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Decay data for the positron emission tomography imaging radionuclide 124I: A DDEP evaluation
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Decay data for the positron emission tomography imaging radionuclide 124I: A DDEP evaluation B.E. Zimmerman Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8462, USA
H I G H L I G H T S evaluation of the decay data for I is presented. • ANewnewrecommended values for gamma emission rates calculated with recent published data. • Recommended positron rates calculated. • Atomic data relevant to emission decay studies provided. • 124
A R T I C L E I N F O
A B S T R A C T
Keywords: Positron-emission probabilities Decay data evaluation DDEP Gamma-ray probabilities 124 I
A new decay data evaluation for the positron emitting radionuclide 124I has been performed using the Decay Data Evaluation Project (DDEP) methodology. New recommended values for the half-life, γ-ray emission probabilities, β+ branching ratios, and other relevant nuclear and atomic data are provided. This paper provides a summary of the evaluation; the complete set of recommended data tables and detailed evaluator comments are available at the DDEP website.
1. Introduction Even though the majority of Positron Emission Tomography (PET) studies continue to be carried out using 18F, an increasing number of positron-emitting radionuclides are being developed as diagnostic agents for specific diseases. One such nuclide is 124I, which is being investigated as a PET imaging surrogate for dosimetry assessments of the widely-used therapeutic radionuclide 131I (Jentzen et al., 2007; Zechmann et al., 2014). In addition, many new 124I labeled compounds, such as [124I]-M-iodobenzylguanidine ([124I]-MIBG) for diagnosis of neuroblastoma (Koehler et al., 2010), are finding use in a wide variety of clinical applications. Unlike the “traditional” PET radionuclides (e.g., 11C, 13N, 15O, 18F), whose half-lives are on the order of minutes, longer-lived radionuclides such as 124I (T1/2 = 4.17 d) are able to image physiological processes that have longer time scales. In addition to the longer half-life, 124I has a much more complex decay scheme than most of the other PET radionuclides being considered. Quantitative clinical imaging applications with 124I, especially those involving dosimetry, require accurate, critically evaluated data. The currently recommended decay data for 124I that are in wide use come from the Evaluated Nuclear Structure Data File (ENSDF)
evaluation published by Katakura and Wu (2008). The publication of more recent experimental data, especially the photon emission probability data of Luca et al. (2016), have prompted the need for a new evaluation. A summary of the important results of a new evaluation of 124I decay data, which was carried out using the Decay Data Evaluation Project (DDEP) methodology (Kellett and Bersillon, 2017), is given in this paper. Full tabulations of recommended values for the main decay scheme parameters, along with a file containing a detailed explanation of the procedure used in the evaluation are available from the DDEP website (http://www.nucleide.org/DDEP_WG/DDEPdata.htm). 2. Evaluation methodology All uncertainties given in this evaluation are presented as corresponding to a single (k = 1) uncertainty interval. Most calculations were performed in a spreadsheet program and the final results transferred manually into the SAISINUC program (Dulieu et al., 2017) that is used by DDEP to organize all the results of the evaluation. Average values of the evaluated decay parameters were determined using a spreadsheet add-in (LWEIGHT) that implements the Limitation of Relative Statistical Weights Method (Browne, 1998 and
E-mail address: [email protected]. http://dx.doi.org/10.1016/j.apradiso.2017.10.051 Received 28 February 2017; Received in revised form 25 October 2017; Accepted 30 October 2017 0969-8043/ Published by Elsevier Ltd.
Please cite this article as: Zimmerman, B.E., Applied Radiation and Isotopes (2017), http://dx.doi.org/10.1016/j.apradiso.2017.10.051
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Fig. 1. Partial level scheme showing (on the left side) the decay of the level at 2039 keV under the assumptions of Doll et al. (2000) in which the level is a doublet with each state decaying by doublet γ-ray transitions. The transitions are shown schematically, since the discrete energies and individual intensities have not been measured. The scheme on the right shows the decay as assumed in this evaluation and discussed in the text. In both cases, the placement of the 2038.43 keV γ-ray that feeds the first excited state is shown.
into them by β+ and EC decay was 0.25%.
references therein). Several external programs can be called within SAISINUC and the results directly entered into the database. This includes BrICC (Kibédi et al., 2008) for calculating internal conversion coefficients and the 2013 version of the EMISSION code (Schönfeld and Janssen, 2000) for calculating X-ray and Auger electron emission intensities. The SAISINUC program also contains a number of internal databases to calculate certain atomic data. The total Q-value, QTot, was calculated internally using the mass evaluation data of Wang et al. (2012). Fluorescence yields were calculated within the SAISINUC program using the data of Schönfeld and Janssen (1996). X-ray and Auger electron energies were also calculated within the SAISINUC program using the data from Schönfeld and Rodloff (1999) and Schönfeld and Rodloff (1998), respectively.
3.1. The 2039.3 keV level Of particular note in this evaluation is the treatment of the level at 2039.3 keV, which is purported to be a doublet of states at 2039.293 keV and 2039.421 keV with spins and parities of 3+ and 2+, respectively. The presence of a doublet state was first suggested by Berendakov et al. (1990) based on data from the (n,n′) reaction on 124 Te. The data that provide evidence for the doublet appear only in unpublished conference proceedings, so it is difficult to judge their quality. The level scheme proposed by Warr et al. (1998) continued to promote the idea of a doublet state at this energy based on the lack of coincidences in the fairly intense 2039 keV γ-ray gate in their 122Sn (α,2n)124Te reaction data. This led them to suggest a level at an energy at about 2039 keV separate from the one already established through coincidence relationships among several other γ-rays. It should be noted, however, that the tabulated energy value for this γ-ray, 2038.43(8) keV, is inconsistent with the energies assigned to either of the proposed levels near 2039 keV, suggesting that the observed transition is in fact not a ground state transition from either of these states. Their data from 124I decay, published in the same reference, indicate a coincidence relationship between the 2039 keV γ-ray and first excited state transition at 603 keV, suggesting that the 2039 keV γ-ray depopulates the level at 2641 keV. This same coincidence relationship was also observed earlier by Ragaini et al. (1969), who proposed that the 2039 keV state could be the 3+ member of the n = 3 phonon multiplet. This is supported by systematics of the locations of the 3+ 3rd-phonon states in the neighboring Te nuclei. The main evidence for a doublet comes from the resolved splitting of the 1437 keV γ-ray that proceeds from the 2039 keV state to the 603 keV first excited state observed by Doll et al. (2000), which is interpreted as a splitting of the 2039 keV level. There are, however, no supporting coincidence data to support placement of the transitions. If the 2039 keV level is a doublet and the two levels de-excite according to the scheme proposed by Doll et al. (2000) and shown in Fig. 1, it would
3. Decay scheme Iodine-124 decays by electron capture (EC) and β+ emission to a total of 28 levels in 124Te. The 124Te decay daughter is stable. As with the current ENSDF evaluation (Katakura and Wu, 2008), spins and parities, transition multipolarities and mixing ratios, as well as γ-ray placements in this evaluation are based on the level scheme proposed by Warr et al. (1998). Additional transitions from the work of Ragaini et al. (1969) and Ghiҭӑ et al. (2008) were also included as placed in the respective references. For transitions in which no published multipolarities are given, assignments are proposed on the basis of selection rules. Unplaced γ-rays were not included in this evaluation regardless of the data source. Level energies are taken from the ENSDF Adopted Levels table (Katakura and Wu, 2008). By considering additional data sets, a total of 3 levels and 18 γ-rays were added to the decay scheme relative to the ENSDF 124I decay evaluation. The level scheme as presented is complete and consistent. This is demonstrated by agreement between QCalc = 3152(19) keV obtained from sum of the average energies and probabilities of all the transitions and the theoretical Q-value, QTot = 3159.6(19) keV. The difference between the summation of all decay out of the levels and the feeding 2
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require the three transitions that de-excite the level (714 keV, 791 keV, and 1437 keV) to all be doublets in addition to the 2039 keV γ-ray being doubly placed. There are currently no published data to support such a proposed scheme. From a practical perspective, there are currently no data to enable the calculation of feeding intensities in and out of a 2039 keV doublet, as the partitioning of observed intensity has yet to be reported. With this information in hand, we propose that the level at 2039 keV be considered to be populated in decay as a singlet state with spin and parity 3+ until such time as more convincing experimental data are available. This proposed configuration is shown in Fig. 1. This is obviously an area in which additional spectroscopic studies from 124I decay are needed. With the appropriate coincidence (perhaps higher than 2-fold) data and high resolution spectroscopy, the nature of this state can hopefully be resolved and the feeding intensity pattern deduced. Within the current levels of uncertainty, however, the level scheme and associated data as given in the full evaluation are internally consistent.
Table 2 List of recommended absolute γ-ray probabilities (per 100 decays), Pγ, in the decay of 124I and their associated uncertainties, s.
4. Half-life The recommended half-life from the ENSDF evaluation (Katakura and Wu, 2008) is 4.1760(3) d and is the value reported by Woods et al. (1992). All of the experimentally-determined, published half-life values with associated uncertainties available in the literature were considered in this evaluation. These are given in Table 1 and lead to an evaluated half-life of 4.1760(3) d, which is identical to the ENSDF value. The bulk of the weight is carried by the two most recent results (Woods et al., 1992; Luca et al., 2016), with the former having a lower uncertainty by a factor of more than 4 and a factor of 100 from the next lowest reported uncertainty. The reported value from Ruan et al. (1967) was excluded as an outlier by LWEIGHT based on the Chauvenet criteria (Chauvenet, 1891). 5. Photon energies and transition probabilities 5.1. Gamma ray energies and intensities High-resolution gamma-ray spectroscopy data were considered from six primary sources: (Lagrange, 1968; Ragaini et al., 1969; Woods et al., 1992; Warr et al., 1998; Ghiҭӑ et al., 2008; Luca et al., 2016). To within their respective uncertainties, all of the data sets are consistent with one another. The γ-ray intensity data of an additional reference (Bechvarzh et al., 1970) were found to be inconsistent with the other data sets and were therefore not included in the calculation of recommended values. The list of the recommended γ-ray intensities and uncertainties from this evaluation is given in Table 2. The complete list of all γ-rays Table 1 Experimental half-life determinations of
124
I considered in this evaluation.
Reference
T1/2 (d)
Uncertainty (d)
Dyson and Francois (1958) Girgis and van Lieshout (1959) Andersson et al. (1965) Ruan and Inoue (1967)a Jonsson and Forkman (1968) Karim (1973) Woods et al. (1992) Luca et al. (2016) Recommendedb
4.24 4.1 4.15 4.3 4.1 4.15 4.1760 4.1758 4.1760
0.05 0.1 0.03 0.08 0.2 0.08 0.0003 0.0014 0.0003
a
Rejected by LWEIGHT by the Chauvenet principle. The recommended half-life is the weighted mean of all the above values, with the exception of Ruan and Inoue (1967). Most of the weight (99.98%) is from Woods et al. (1992) and Luca et al. (2016) due to their small uncertainties. The uncertainty on the recommended half-life is the standard deviation of the weighted values. b
3
Energy (keV)
Pγ, per 100 decays
s, per 100 decays
166.04 307.34 335.67 351.47 370.4b 402.8 443.88 468.5b 490.9b 517.8 525.45 541.19 550.75 557.14 592.34 602.73 609.92 645.85 661.04b 662.1 678.3b 707.46 709.36 713.75 722.78 735.8b 743.19 766.09 776.1 790.76 794.7b 795.63 797.1b 846.8 876.97 899.43 928c 961.84 968.19 976.35 984.4c 998.3b 1045.11 1054.54 1086.4 1128.58 1196 1205.44 1315.67 1325.52 1355.2 1368.18 1376.09 1392.7b 1436.64 1445.17 1488.92 1509.36 1560.53 1586.1 1622.22 1637.43 1658a 1663.7b 1675.6 1690.96 1705.63 1720.21 1752.51 1851.37 1918.56 2038.43 2078.67
0.008 0.017 0.018 0.016 0.003 0.013 0.038 0.008 0.028 0.023 0.029 0.208 0.007 0.025 0.109 62.9 0.148 0.986 0.011 0.055 0.004 0.093 0.044 0.078 10.36 0.013 0.013 0.005 0.013 0.026 0.003 0.038 0.004 0.004 0.023 0.022 0.002 0.018 0.441 0.104 0.014 0.026 0.439 0.124 0.027 0.0457 0.003 0.023 0.029 1.57 0.036 0.297 1.77 0.014 0.076 0.037 0.202 3.20 0.165 0.006 0.049 0.204
0.003 0.003 0.003 0.004 0.001 0.003 0.003 0.004 0.003 0.003 0.002 0.002 0.005 0.016 0.008 0.6 0.003 0.006 0.002 0.002 0.001 0.002 0.001 0.003 0.08 0.008 0.001 0.001 0.002 0.001 0.001 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.003 0.002 0.003 0.002 0.005 0.002 0.003 0.0007 0.002 0.003 0.002 0.01 0.001 0.003 0.01 0.003 0.002 0.002 0.002 0.02 0.003 0.001 0.001 0.002
0.003 0.108 11.04 0.0092 0.181 0.053 0.215 0.170 0.346 0.358
0.001 0.002 0.08 0.0021 0.005 0.001 0.002 0.003 0.005 0.005 (continued on next page)
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Table 2 (continued) Energy (keV)
Pγ, per 100 decays
s, per 100 decays
2090.94 2098.81 2144.21 2214.8b 2232.03 2256.7b 2283.06 2294.4c 2385.1 2453.9c 2681.5c 2746.9c 2987.6c
0.599 0.151 0.103 0.006 0.576 0.003 0.60 0.008 0.015 0.053 0.032 0.473 0.0085
0.007 0.002 0.002 0.001 0.013 0.001 0.05 0.002 0.002 0.008 0.004 0.017 0.002
a b c
Table 3 Comparison of experimental and theoretical αK values for gamma transitions observed in the decay of 124I. The γ-ray energies correspond to the same energies that appear in Table 2. Energy (keV)
335.67 443.88 525.45 602.73 645.85 709.36 713.75 722.78 790.76 968.19 976.35 1045.11 1054.54 1325.52 1355.2 1368.18 1376.09 1436.64 1445.17 1488.92 1509.36 1560.53 1658 1675.6 1690.96 1720.21 1851.37 2038.43 2078.67 2090.94 2232.03 2283.06 2453.9
E0 transition. Energy from Ghiҭӑ et al. (2008). Energy from Ragaini et al. (1969).
considered in the evaluation is given in the evaluator comments file on the DDEP website. The transition energies are from Warr et al. (1998) unless otherwise noted. With the exception of the emission probabilities reported by Luca et al. (2016), the conversion of relative γ-ray intensities to absolute intensities was done by applying the factor of 0.0629(6) that was determined by Woods et al. (1992) from observed photon emission rates and an absolute activity measurement. The value determined by Woods et al. (1992) was favored primarily because of its much lower uncertainty (0.95%, compared to 3.3%). The normalization factor calculated by Luca et al. (2016) was maintained for their data because the work represented a recent determination and was the only other measurement of emission probabilities that was linked to an independent primary standardization. 5.2. Multipolarities and internal conversion coefficients Gamma-ray multipolarities were assigned based on the spins and parities of the initial and final states. Mixing ratios, when available, were taken from Warr et al. (1998). Internal conversion coefficients were calculated using BrICC (Kibédi et al., 2008) with the frozen orbital approximation. Experimental mixing ratios were used in the calculations when available; otherwise, equal mixing between the multipolarities (i.e., δ = 1) was assumed. The calculated αK values are given in Table 3, along with the experimental results of Bechvarzh et al. (1970) and Grigorev et al. (1969) for comparison. Although the γ-ray data of Bechvarzh et al. (1970) were inconsistent with the other available data sets, primarily due to poor energy resolution (which led to incorrect intensity values for many of the transitions), the highest intensity γ-rays were reasonably separated and allowed for determination of αK for those transitions. The minor disagreement in the calculated αK for the 1325 keV transition between this work (0.77(8)) and the ENSDF evaluation (0.693(10), Katakura and Wu, 2008) lies primarily in the assignment of multipolarity. The experimental αK values given by both Bechvarzh et al. (1970) and Grigorev et al. (1969) are higher than the theoretical value given in the ENSDF evaluation that was based on the assumption of a pure E2 transition. If the transition is treated as having mixed M1+E2 nature, which is reasonable given the initial and final level spins and parities, the higher calculated theoretical αK is in much better agreement with experiment. For the case of the 1851 keV γ-ray, Warr et al. (1998) suggest that the transition is of M1+E2 character and report a mixing ratio of δ = 0.039(1) from their 122Sn(α,2n)124Te data (i.e., not from 124I decay). However, the calculated αK from these parameters is not consistent with the measured value of Bechvarzh et al. (1969) that assumes M2+E3. Both proposed multipolarities are plausible from the existing level spin and parity assignments. However, better agreement between
(Bechvarzh et al., 1970)a αK,exp·103 multipolarity
4.31 3.22(60)
E2 E2
2.46(55)
M1+E2
0.73(30)
(Grigorev et al., 1969)b αK,exp·103 multipolarity
4.2 3.4(3)
E2 E2
2.4(4) 2.6(3) 2.0(5) 0.62(13)
M1+E2 M1+E2 M1+E2 E1
E1+M2
0.49(10)
E1
0.86(20)
M1+E2
0.47(15) 0.35(4)
E1 E1
0.78(20) 0.69(13) 0.31(6)
E2 M1+E2 E1
0.54(12)
M1+E2
0.70(15)
M1+E2
unresolved 0.30(5)
E1 E0
0.20(2) 0.47(15) 0.62(15) 0.31(5) 0.35(5) 0.20(5) 0.15(4) 0.13(4)
E1 M1+E2 E3+M2 M1+E2 M1+E2 E1 E1 E1
0.21(3)
E1
0.14(5)
E1
Recommended αK,Calc·103 multipolarity 6.13(9) 9.7(1) 6.6(6) 4.20(6) 3.51(5) 3.49(5) 2.73(4) 2.71(4) 2.13(5) 0.569(9) 1.56(3) 0.494(9) 1.11(2) 0.77(8) 0.92(20) 0.303(5) 0.300(5) 0.591(9) 0.29(4) 0.66(1) 0.256(4) 0.28(10) – 0.48(4) 0.213(3) 0.48(1) 0.416(6) 0.32(2) 0.327(5) 0.152(2) 0.138(5) 0.134(2) 0.219(3)
E1 E2 M1+E2 E2 E2 M1+E2 E2 M1+E2 E2 E1+M2 M1+E2 E1+M2 E2 M1+E2 E2+M3 E1+M2 E1+M2 E2 E1+M2 M1+E2 E1 E1+M2 E0 M1+E2 E1+M2 M1+E2 M1+E2 M1+E2 M1+E2 E1+M2 E1+M2 E1+M2 E2
a The gamma-ray energies, Eγ, given in this reference appear to suffer from a poor energy calibration. Data are provided only for transitions in which the Eγ unambiguously agrees with the recommended values. b Transitions are populated from the decay of 124Sb. The gamma-rays at 707.46 keV and 709.36 keV are unresolved in this work, thus the authors’ reported αK,exp for their observed transition at 708.9 keV is not given here.
theoretical and experimental αK is achieved with the M2+E3 assignment. The result calculated with this assumption is adopted in this evaluation. 6. β+ and electron capture transitions Maximum positron energies were calculated from the adopted Qvalue and the level energies in the 124Te decay daughter, appropriately accounting for the annihilated positron and electron rest masses. Transition probabilities were deduced from the imbalance in total intensities of the γ-rays feeding into and out of each level. Where energetically possible, the relative fractions of β+ and EC decay for each level were calculated with the LOGFT program (based on the work of Gove and Martin 1971), as were the log ft values for each level. Electron capture PK, PL, and PM probabilities were also calculated using the LOGFT program. The calculated β+ endpoint energies and emission rates are compared with published experimental data (Mitchell et al., 1959; Girgis and van Lieshout, 1959; Ruan and Inoue, 1967; Bechvarzh et al., 1970; Woods et al., 1992; and Qaim et al., 2007) in Table 4. The total calculated β+ emission rate calculated in this evaluation is consistent with the most recent experimental data from Qaim et al. (2007), but barely overlaps the value from Woods et al. (1992) at the level of a single uncertainty interval. In general, the currently available experimental 4
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21.62(41) Iβ+,Total+ =
22.1(5) 0.32(9) 753(50) < 0.5
Iβ+,Total+ = 10.59(21) 10.71(25) 2138.3(21) 1543.7(65) 10.9 10.5
Iβ+, % Eβ+,max, keV Iβ+, % Eβ+,max, keV
data are of relatively poor quality and could benefit from new measurements with higher-resolution instrumentation, particularly with regards to the characterization of the two weakest β+ branches and spectral shapes for all the β+ transitions. 7. Conclusion This new evaluation of the decay data for 124I provides new recommended values for the most relevant decay data, including the halflife and energies and emission probabilities for β+ emission, γ-rays, Xrays, conversion electrons, and Auger electrons. By considering six sources of γ-ray emission data in the literature, 3 new levels and 18 γrays were added to the previously-recommended level scheme. The full listing of data, along with a detailed explanation of the evaluation process, is given on the DDEP website.
21.4 Iβ+,Total+ =
790(30)
2136(10) 1520(15)
Iβ+, % Eβ+,max, keV
The author would like to thank Mr. Christophe Dulieu (CEA-LNHB) for his assistance with the SAISINUC program and Dr. Mark Kellett (CEA-LNHB) for his encouragement and patience with this first-time evaluator.
c
b
a
2.2
28.6
786(50)
Iβ+,Total+ =
No uncertainty provided. Calculated from total β+ probability and relative intensities. Authors indicate that intensity is distributed among three levels between 1350 keV and 1248 keV.
26.5(35) Iβ+,Total+ =
13.1 13.3 2130(20) 1531(30)
10.6(2) 11.7(2) 1.9(16) × 10−4 0.293(11) 1.25(10) × 10−4 22.59(28) 0.0 602.7271 1248.5811 1325.5131 1657.283 β+0,0 β+0,1 β+0,2 β+0,3 β+0,4
2137.5(19) 1534.8(19) 888.9(19) 812.0(19) 480.3(19) Iβ+,Total+ =
Iβ+, % Eβ+,max, keV Level, keV Transition
Iβ+, % Eβ+,max, keV
Andersson, G., Rudstam, G., Sörensen, G., 1965. Decay data on some Xe, I, and Te isotopes. Ark. Fys. 28, 37. Bechvarzh, F., Gromov, K.Y., Zhelev, Z.T., Zaitseva, N.G., Loshchilov, M.G., Nazarov, U.K., Sabirov, S.S., 1970. Investigation of the radiation of 124I. Bull. Acad. Sci. USSR Phys. Ser. 33, 1228. Berendakov, S.A., Govor, L.I., Demidov, A.M., Mikhailov, I.V., 1990. Comparison of the de-excitation schemes of the complete system of levels of 122−130Te up to excitation energy 2.5 MeV. Sov. J. Nucl. Phys. 52, 389. Browne, E., 1998. Limitation of Relative Statistical Weights, A Method for Evaluating Discrepant Data. INDC(NDS)−363, Appendix 1. International Atomic Energy Agency, Vienna. Chauvenet, W., 1891. A Manual of Spherical and Practical Astronomy, 5th ed. Lippincott Company, Philadelphia (Appendix). Doll, C., Lehmann, H., Borner, H.G., von Egidy, T., 2000. Lifetime measurement in 124Te. Nucl. Phys. A672, 3. Dulieu, C., Kellett, M.A., Mougeot, X., 2017. Dissemination and visualisation of reference decay data from Decay Data Evaluation Project (DDEP). EPJ Web Conf. 146, 07004. Dyson, N.A., Francois, P.E., 1958. Some observations on the decay of iodine-124 and their implications in radioiodine therapy. Phys. Med. Biol. 3, 111. Ghiҭӑ, D.G., Cata-Danil, G., Bucurescu, D., Cata-Danil, I., Ivascu, M., Mihai, C., Suliman, G., Stroe, L., Sava, T., Zamfir, N.V., 2008. 124Te and the E(5) critical point symmetry. Int. J. Mod. Phys. E17, 1453. Girgis, R.K., van Lieshout, R., 1959. Gamma radiation following the decay of 124Sb and 124 I. Physica 25, 133. Gove, N.B., Martin, M.M., 1971. Log f tables for beta decay. At. Data Nucl. Data Tab. A10, 205. Grigorev, E.P., Zolotavin, A.V., Sergeev, V.O., Sovtsov, M.I., 1969. Bill. Acad. Sci. USSR Phys. Ser. 32, 711. Jentzen, W., Freudenberg, L., Eising, E.G., Sonnenschein, W., Knust, J., Bockisch, A., 2007. Optimized 124I PET dosimetry protocol for radioiodine therapy of differentiated thyroid cancer. J. Nucl. Med. 49, 1017. Jonsson, G.G., Forkman, B., 1968. (γ,xn) reactions in 127I. Nucl. Phys. A107, 52. Karim, H.M., 1973. A study of 4 GeV electron spallation products of iodine. Radiochim. Acta 19, 1. Katakura, J., Wu, Z.D., 2008. Nuclear data sheets for A = 124. Nucl. Data Sheets 109, 1655. Kellett, M.A., Bersillon, O., 2017. The Decay Data Evaluation Project (DDEP) and the JEFF-3.3 radioactive decay data library: combining international collaborative efforts on evaluated decay data. EPJ Web Conf. 146, 02009. Kibédi, T., Burrows, T.W., Trzhaskovskaya, M.B., Davidson, P.M., Nestor Jr., C.W., 2008. Evaluation of theoretical conversion coefficients using BrICC. Nucl. Instrum. Methods Phys. Res. A 589, 202. Koehler, L., Gagnon, K., McQuarrie, S., Wuest, F., 2010. Iodine-124: a promising positron emitter for organic PET chemistry. Molecules 15, 2686. Lagrange, J.-M., 1968. Etude du Schema de Desintegration de l′Iode-124. Compt. Rend. 267B, 1354. Luca, A., Sahagia, M., Ioan, M.-R., Antohe, A., Neascu, B.L., 2016. Experimental determination of some nuclear decay data in the decays of 177Lu, 1886Re, and 124I. Appl. Radiat. Isot. 109, 146–150. Mitchell, A.C.G., Juliano, J.O., Creager, C.B., Kocher, C.W., 1959. Disintegration of 124I and 123I. Phys. Rev. 113, 628. Qaim, S.M., Bisinger, T., Hilgers, K., Nayak, D., Coenen, H.H., 2007. Positron emission intensities in the decay of 64Cu, 76Br, and 124I. Radiochim Acta 95, 67.
800a
11(3) 14(4) 0.5(5)c
2146(15) 1542(20)
Iβ+, % Eβ+,max, keV Iβ+, % Eβ+,max, keV
Ruan and Inoue (1967) Girgis and van Lieshout (1959)
Acknowledgements
References
a
Mitchell et al. (1959) This evaluation
Table 4 Comparison of recommended and experimental β+ endpoint energies, Eβ+,max, and emission probabilities, Iβ+.
a
Bechvarzh et al. (1970)
a
Woods et al. (1992)
b
Qaim et al. (2007)
B.E. Zimmerman
5
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B.E. Zimmerman Ragaini, R.C., Walters, W.B., Meyer, R.A., 1969. Levels of 124Te from the decay of 4.2-Day 124 I. Phys. Rev. 187, 1721. Ruan, J.-Z., Inoue, H., 1967. Decay of 124I. J. Phys. Soc. Jpn. 23, 481. Schönfeld, E., Janssen, R., 1996. Evaluation of atomic shell data. Nucl. Instrum. Methods Phys. Res. A 369, 527. Schönfeld, E., Rodloff, G., 1998. Tables of the Energies of K-Auger Electrons for Elements with Atomic Numbers in the Range from Z = 11 to Z = 100, PTB Report PTB-6.1198-1. Schönfeld, E., Rodloff, G., 1999, Energies and Relative Emission Probabilities of K X-rays for Elements with Atomic Numbers in the Range from Z = 5 to Z = 100, PTB Report PTB-6.11-1999-1. Schönfeld, E., Janssen, H., 2000. Calculation of emission probabilities of X-rays and Auger electrons emitted in radioactive disintegration processes. Appl. Radiat. Isot. 52, 595.
Wang, M., Audi, G., Wapstra, A.H., Kondev, F.G., MacCormick, M., Xu, X., Pfeiffer, B., 2012. The AME2012 atomic mass evaluation (II). Tables, graphs and references. Chin. Phys. C 36, 1603. Warr, N., Drissi, S., Garrett, P.E., Jolie, J., Kern, J., Lehmann, H., Mannana, S.J., Vorlet, J.-P., 1998. Study of 124Te by the 122Sn(α,2nγ) reaction and by the decay of 124I. Nucl. Phys. A636, 379. Woods, D.H., Woods, S.A., Woods, M.J., Makepeace, J.L., Downey, C.W.A., Smith, D., Munster, A.S., Lucas, S.E.M., Sharma, H., 1992. The standardization and measurement of decay scheme data of 124I. Appl. Radiat. Isot. 43, 551. Zechmann, C.M., Oromieh, A.A.-, Armor, T., Stubbs, J.B., Mier, W., Hadaschik, B., Joyal, J., Kopka, K., Debus, J., Babich, J.W., Haberkorn, U., 2014. Radiation dosimetry and first therapy results with a 124I/131I-labeled small molecule (MIP-1095) targeting PSMA for prostate cancer therapy. Eur. J. Nucl. Med. Mol. Imaging 41 (7), 1280.
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Contents lists available at ScienceDirect
Applied Radiation and Isotopes journal homepage: www.elsevier.com/locate/apradiso
Decay data for the positron emission tomography imaging radionuclide 124I: A DDEP evaluation B.E. Zimmerman Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8462, USA
H I G H L I G H T S evaluation of the decay data for I is presented. • ANewnewrecommended values for gamma emission rates calculated with recent published data. • Recommended positron rates calculated. • Atomic data relevant to emission decay studies provided. • 124
A R T I C L E I N F O
A B S T R A C T
Keywords: Positron-emission probabilities Decay data evaluation DDEP Gamma-ray probabilities 124 I
A new decay data evaluation for the positron emitting radionuclide 124I has been performed using the Decay Data Evaluation Project (DDEP) methodology. New recommended values for the half-life, γ-ray emission probabilities, β+ branching ratios, and other relevant nuclear and atomic data are provided. This paper provides a summary of the evaluation; the complete set of recommended data tables and detailed evaluator comments are available at the DDEP website.
1. Introduction Even though the majority of Positron Emission Tomography (PET) studies continue to be carried out using 18F, an increasing number of positron-emitting radionuclides are being developed as diagnostic agents for specific diseases. One such nuclide is 124I, which is being investigated as a PET imaging surrogate for dosimetry assessments of the widely-used therapeutic radionuclide 131I (Jentzen et al., 2007; Zechmann et al., 2014). In addition, many new 124I labeled compounds, such as [124I]-M-iodobenzylguanidine ([124I]-MIBG) for diagnosis of neuroblastoma (Koehler et al., 2010), are finding use in a wide variety of clinical applications. Unlike the “traditional” PET radionuclides (e.g., 11C, 13N, 15O, 18F), whose half-lives are on the order of minutes, longer-lived radionuclides such as 124I (T1/2 = 4.17 d) are able to image physiological processes that have longer time scales. In addition to the longer half-life, 124I has a much more complex decay scheme than most of the other PET radionuclides being considered. Quantitative clinical imaging applications with 124I, especially those involving dosimetry, require accurate, critically evaluated data. The currently recommended decay data for 124I that are in wide use come from the Evaluated Nuclear Structure Data File (ENSDF)
evaluation published by Katakura and Wu (2008). The publication of more recent experimental data, especially the photon emission probability data of Luca et al. (2016), have prompted the need for a new evaluation. A summary of the important results of a new evaluation of 124I decay data, which was carried out using the Decay Data Evaluation Project (DDEP) methodology (Kellett and Bersillon, 2017), is given in this paper. Full tabulations of recommended values for the main decay scheme parameters, along with a file containing a detailed explanation of the procedure used in the evaluation are available from the DDEP website (http://www.nucleide.org/DDEP_WG/DDEPdata.htm). 2. Evaluation methodology All uncertainties given in this evaluation are presented as corresponding to a single (k = 1) uncertainty interval. Most calculations were performed in a spreadsheet program and the final results transferred manually into the SAISINUC program (Dulieu et al., 2017) that is used by DDEP to organize all the results of the evaluation. Average values of the evaluated decay parameters were determined using a spreadsheet add-in (LWEIGHT) that implements the Limitation of Relative Statistical Weights Method (Browne, 1998 and
E-mail address: [email protected]. http://dx.doi.org/10.1016/j.apradiso.2017.10.051 Received 28 February 2017; Received in revised form 25 October 2017; Accepted 30 October 2017 0969-8043/ Published by Elsevier Ltd.
Please cite this article as: Zimmerman, B.E., Applied Radiation and Isotopes (2017), http://dx.doi.org/10.1016/j.apradiso.2017.10.051
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Fig. 1. Partial level scheme showing (on the left side) the decay of the level at 2039 keV under the assumptions of Doll et al. (2000) in which the level is a doublet with each state decaying by doublet γ-ray transitions. The transitions are shown schematically, since the discrete energies and individual intensities have not been measured. The scheme on the right shows the decay as assumed in this evaluation and discussed in the text. In both cases, the placement of the 2038.43 keV γ-ray that feeds the first excited state is shown.
into them by β+ and EC decay was 0.25%.
references therein). Several external programs can be called within SAISINUC and the results directly entered into the database. This includes BrICC (Kibédi et al., 2008) for calculating internal conversion coefficients and the 2013 version of the EMISSION code (Schönfeld and Janssen, 2000) for calculating X-ray and Auger electron emission intensities. The SAISINUC program also contains a number of internal databases to calculate certain atomic data. The total Q-value, QTot, was calculated internally using the mass evaluation data of Wang et al. (2012). Fluorescence yields were calculated within the SAISINUC program using the data of Schönfeld and Janssen (1996). X-ray and Auger electron energies were also calculated within the SAISINUC program using the data from Schönfeld and Rodloff (1999) and Schönfeld and Rodloff (1998), respectively.
3.1. The 2039.3 keV level Of particular note in this evaluation is the treatment of the level at 2039.3 keV, which is purported to be a doublet of states at 2039.293 keV and 2039.421 keV with spins and parities of 3+ and 2+, respectively. The presence of a doublet state was first suggested by Berendakov et al. (1990) based on data from the (n,n′) reaction on 124 Te. The data that provide evidence for the doublet appear only in unpublished conference proceedings, so it is difficult to judge their quality. The level scheme proposed by Warr et al. (1998) continued to promote the idea of a doublet state at this energy based on the lack of coincidences in the fairly intense 2039 keV γ-ray gate in their 122Sn (α,2n)124Te reaction data. This led them to suggest a level at an energy at about 2039 keV separate from the one already established through coincidence relationships among several other γ-rays. It should be noted, however, that the tabulated energy value for this γ-ray, 2038.43(8) keV, is inconsistent with the energies assigned to either of the proposed levels near 2039 keV, suggesting that the observed transition is in fact not a ground state transition from either of these states. Their data from 124I decay, published in the same reference, indicate a coincidence relationship between the 2039 keV γ-ray and first excited state transition at 603 keV, suggesting that the 2039 keV γ-ray depopulates the level at 2641 keV. This same coincidence relationship was also observed earlier by Ragaini et al. (1969), who proposed that the 2039 keV state could be the 3+ member of the n = 3 phonon multiplet. This is supported by systematics of the locations of the 3+ 3rd-phonon states in the neighboring Te nuclei. The main evidence for a doublet comes from the resolved splitting of the 1437 keV γ-ray that proceeds from the 2039 keV state to the 603 keV first excited state observed by Doll et al. (2000), which is interpreted as a splitting of the 2039 keV level. There are, however, no supporting coincidence data to support placement of the transitions. If the 2039 keV level is a doublet and the two levels de-excite according to the scheme proposed by Doll et al. (2000) and shown in Fig. 1, it would
3. Decay scheme Iodine-124 decays by electron capture (EC) and β+ emission to a total of 28 levels in 124Te. The 124Te decay daughter is stable. As with the current ENSDF evaluation (Katakura and Wu, 2008), spins and parities, transition multipolarities and mixing ratios, as well as γ-ray placements in this evaluation are based on the level scheme proposed by Warr et al. (1998). Additional transitions from the work of Ragaini et al. (1969) and Ghiҭӑ et al. (2008) were also included as placed in the respective references. For transitions in which no published multipolarities are given, assignments are proposed on the basis of selection rules. Unplaced γ-rays were not included in this evaluation regardless of the data source. Level energies are taken from the ENSDF Adopted Levels table (Katakura and Wu, 2008). By considering additional data sets, a total of 3 levels and 18 γ-rays were added to the decay scheme relative to the ENSDF 124I decay evaluation. The level scheme as presented is complete and consistent. This is demonstrated by agreement between QCalc = 3152(19) keV obtained from sum of the average energies and probabilities of all the transitions and the theoretical Q-value, QTot = 3159.6(19) keV. The difference between the summation of all decay out of the levels and the feeding 2
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require the three transitions that de-excite the level (714 keV, 791 keV, and 1437 keV) to all be doublets in addition to the 2039 keV γ-ray being doubly placed. There are currently no published data to support such a proposed scheme. From a practical perspective, there are currently no data to enable the calculation of feeding intensities in and out of a 2039 keV doublet, as the partitioning of observed intensity has yet to be reported. With this information in hand, we propose that the level at 2039 keV be considered to be populated in decay as a singlet state with spin and parity 3+ until such time as more convincing experimental data are available. This proposed configuration is shown in Fig. 1. This is obviously an area in which additional spectroscopic studies from 124I decay are needed. With the appropriate coincidence (perhaps higher than 2-fold) data and high resolution spectroscopy, the nature of this state can hopefully be resolved and the feeding intensity pattern deduced. Within the current levels of uncertainty, however, the level scheme and associated data as given in the full evaluation are internally consistent.
Table 2 List of recommended absolute γ-ray probabilities (per 100 decays), Pγ, in the decay of 124I and their associated uncertainties, s.
4. Half-life The recommended half-life from the ENSDF evaluation (Katakura and Wu, 2008) is 4.1760(3) d and is the value reported by Woods et al. (1992). All of the experimentally-determined, published half-life values with associated uncertainties available in the literature were considered in this evaluation. These are given in Table 1 and lead to an evaluated half-life of 4.1760(3) d, which is identical to the ENSDF value. The bulk of the weight is carried by the two most recent results (Woods et al., 1992; Luca et al., 2016), with the former having a lower uncertainty by a factor of more than 4 and a factor of 100 from the next lowest reported uncertainty. The reported value from Ruan et al. (1967) was excluded as an outlier by LWEIGHT based on the Chauvenet criteria (Chauvenet, 1891). 5. Photon energies and transition probabilities 5.1. Gamma ray energies and intensities High-resolution gamma-ray spectroscopy data were considered from six primary sources: (Lagrange, 1968; Ragaini et al., 1969; Woods et al., 1992; Warr et al., 1998; Ghiҭӑ et al., 2008; Luca et al., 2016). To within their respective uncertainties, all of the data sets are consistent with one another. The γ-ray intensity data of an additional reference (Bechvarzh et al., 1970) were found to be inconsistent with the other data sets and were therefore not included in the calculation of recommended values. The list of the recommended γ-ray intensities and uncertainties from this evaluation is given in Table 2. The complete list of all γ-rays Table 1 Experimental half-life determinations of
124
I considered in this evaluation.
Reference
T1/2 (d)
Uncertainty (d)
Dyson and Francois (1958) Girgis and van Lieshout (1959) Andersson et al. (1965) Ruan and Inoue (1967)a Jonsson and Forkman (1968) Karim (1973) Woods et al. (1992) Luca et al. (2016) Recommendedb
4.24 4.1 4.15 4.3 4.1 4.15 4.1760 4.1758 4.1760
0.05 0.1 0.03 0.08 0.2 0.08 0.0003 0.0014 0.0003
a
Rejected by LWEIGHT by the Chauvenet principle. The recommended half-life is the weighted mean of all the above values, with the exception of Ruan and Inoue (1967). Most of the weight (99.98%) is from Woods et al. (1992) and Luca et al. (2016) due to their small uncertainties. The uncertainty on the recommended half-life is the standard deviation of the weighted values. b
3
Energy (keV)
Pγ, per 100 decays
s, per 100 decays
166.04 307.34 335.67 351.47 370.4b 402.8 443.88 468.5b 490.9b 517.8 525.45 541.19 550.75 557.14 592.34 602.73 609.92 645.85 661.04b 662.1 678.3b 707.46 709.36 713.75 722.78 735.8b 743.19 766.09 776.1 790.76 794.7b 795.63 797.1b 846.8 876.97 899.43 928c 961.84 968.19 976.35 984.4c 998.3b 1045.11 1054.54 1086.4 1128.58 1196 1205.44 1315.67 1325.52 1355.2 1368.18 1376.09 1392.7b 1436.64 1445.17 1488.92 1509.36 1560.53 1586.1 1622.22 1637.43 1658a 1663.7b 1675.6 1690.96 1705.63 1720.21 1752.51 1851.37 1918.56 2038.43 2078.67
0.008 0.017 0.018 0.016 0.003 0.013 0.038 0.008 0.028 0.023 0.029 0.208 0.007 0.025 0.109 62.9 0.148 0.986 0.011 0.055 0.004 0.093 0.044 0.078 10.36 0.013 0.013 0.005 0.013 0.026 0.003 0.038 0.004 0.004 0.023 0.022 0.002 0.018 0.441 0.104 0.014 0.026 0.439 0.124 0.027 0.0457 0.003 0.023 0.029 1.57 0.036 0.297 1.77 0.014 0.076 0.037 0.202 3.20 0.165 0.006 0.049 0.204
0.003 0.003 0.003 0.004 0.001 0.003 0.003 0.004 0.003 0.003 0.002 0.002 0.005 0.016 0.008 0.6 0.003 0.006 0.002 0.002 0.001 0.002 0.001 0.003 0.08 0.008 0.001 0.001 0.002 0.001 0.001 0.002 0.002 0.002 0.001 0.001 0.001 0.001 0.003 0.002 0.003 0.002 0.005 0.002 0.003 0.0007 0.002 0.003 0.002 0.01 0.001 0.003 0.01 0.003 0.002 0.002 0.002 0.02 0.003 0.001 0.001 0.002
0.003 0.108 11.04 0.0092 0.181 0.053 0.215 0.170 0.346 0.358
0.001 0.002 0.08 0.0021 0.005 0.001 0.002 0.003 0.005 0.005 (continued on next page)
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Table 2 (continued) Energy (keV)
Pγ, per 100 decays
s, per 100 decays
2090.94 2098.81 2144.21 2214.8b 2232.03 2256.7b 2283.06 2294.4c 2385.1 2453.9c 2681.5c 2746.9c 2987.6c
0.599 0.151 0.103 0.006 0.576 0.003 0.60 0.008 0.015 0.053 0.032 0.473 0.0085
0.007 0.002 0.002 0.001 0.013 0.001 0.05 0.002 0.002 0.008 0.004 0.017 0.002
a b c
Table 3 Comparison of experimental and theoretical αK values for gamma transitions observed in the decay of 124I. The γ-ray energies correspond to the same energies that appear in Table 2. Energy (keV)
335.67 443.88 525.45 602.73 645.85 709.36 713.75 722.78 790.76 968.19 976.35 1045.11 1054.54 1325.52 1355.2 1368.18 1376.09 1436.64 1445.17 1488.92 1509.36 1560.53 1658 1675.6 1690.96 1720.21 1851.37 2038.43 2078.67 2090.94 2232.03 2283.06 2453.9
E0 transition. Energy from Ghiҭӑ et al. (2008). Energy from Ragaini et al. (1969).
considered in the evaluation is given in the evaluator comments file on the DDEP website. The transition energies are from Warr et al. (1998) unless otherwise noted. With the exception of the emission probabilities reported by Luca et al. (2016), the conversion of relative γ-ray intensities to absolute intensities was done by applying the factor of 0.0629(6) that was determined by Woods et al. (1992) from observed photon emission rates and an absolute activity measurement. The value determined by Woods et al. (1992) was favored primarily because of its much lower uncertainty (0.95%, compared to 3.3%). The normalization factor calculated by Luca et al. (2016) was maintained for their data because the work represented a recent determination and was the only other measurement of emission probabilities that was linked to an independent primary standardization. 5.2. Multipolarities and internal conversion coefficients Gamma-ray multipolarities were assigned based on the spins and parities of the initial and final states. Mixing ratios, when available, were taken from Warr et al. (1998). Internal conversion coefficients were calculated using BrICC (Kibédi et al., 2008) with the frozen orbital approximation. Experimental mixing ratios were used in the calculations when available; otherwise, equal mixing between the multipolarities (i.e., δ = 1) was assumed. The calculated αK values are given in Table 3, along with the experimental results of Bechvarzh et al. (1970) and Grigorev et al. (1969) for comparison. Although the γ-ray data of Bechvarzh et al. (1970) were inconsistent with the other available data sets, primarily due to poor energy resolution (which led to incorrect intensity values for many of the transitions), the highest intensity γ-rays were reasonably separated and allowed for determination of αK for those transitions. The minor disagreement in the calculated αK for the 1325 keV transition between this work (0.77(8)) and the ENSDF evaluation (0.693(10), Katakura and Wu, 2008) lies primarily in the assignment of multipolarity. The experimental αK values given by both Bechvarzh et al. (1970) and Grigorev et al. (1969) are higher than the theoretical value given in the ENSDF evaluation that was based on the assumption of a pure E2 transition. If the transition is treated as having mixed M1+E2 nature, which is reasonable given the initial and final level spins and parities, the higher calculated theoretical αK is in much better agreement with experiment. For the case of the 1851 keV γ-ray, Warr et al. (1998) suggest that the transition is of M1+E2 character and report a mixing ratio of δ = 0.039(1) from their 122Sn(α,2n)124Te data (i.e., not from 124I decay). However, the calculated αK from these parameters is not consistent with the measured value of Bechvarzh et al. (1969) that assumes M2+E3. Both proposed multipolarities are plausible from the existing level spin and parity assignments. However, better agreement between
(Bechvarzh et al., 1970)a αK,exp·103 multipolarity
4.31 3.22(60)
E2 E2
2.46(55)
M1+E2
0.73(30)
(Grigorev et al., 1969)b αK,exp·103 multipolarity
4.2 3.4(3)
E2 E2
2.4(4) 2.6(3) 2.0(5) 0.62(13)
M1+E2 M1+E2 M1+E2 E1
E1+M2
0.49(10)
E1
0.86(20)
M1+E2
0.47(15) 0.35(4)
E1 E1
0.78(20) 0.69(13) 0.31(6)
E2 M1+E2 E1
0.54(12)
M1+E2
0.70(15)
M1+E2
unresolved 0.30(5)
E1 E0
0.20(2) 0.47(15) 0.62(15) 0.31(5) 0.35(5) 0.20(5) 0.15(4) 0.13(4)
E1 M1+E2 E3+M2 M1+E2 M1+E2 E1 E1 E1
0.21(3)
E1
0.14(5)
E1
Recommended αK,Calc·103 multipolarity 6.13(9) 9.7(1) 6.6(6) 4.20(6) 3.51(5) 3.49(5) 2.73(4) 2.71(4) 2.13(5) 0.569(9) 1.56(3) 0.494(9) 1.11(2) 0.77(8) 0.92(20) 0.303(5) 0.300(5) 0.591(9) 0.29(4) 0.66(1) 0.256(4) 0.28(10) – 0.48(4) 0.213(3) 0.48(1) 0.416(6) 0.32(2) 0.327(5) 0.152(2) 0.138(5) 0.134(2) 0.219(3)
E1 E2 M1+E2 E2 E2 M1+E2 E2 M1+E2 E2 E1+M2 M1+E2 E1+M2 E2 M1+E2 E2+M3 E1+M2 E1+M2 E2 E1+M2 M1+E2 E1 E1+M2 E0 M1+E2 E1+M2 M1+E2 M1+E2 M1+E2 M1+E2 E1+M2 E1+M2 E1+M2 E2
a The gamma-ray energies, Eγ, given in this reference appear to suffer from a poor energy calibration. Data are provided only for transitions in which the Eγ unambiguously agrees with the recommended values. b Transitions are populated from the decay of 124Sb. The gamma-rays at 707.46 keV and 709.36 keV are unresolved in this work, thus the authors’ reported αK,exp for their observed transition at 708.9 keV is not given here.
theoretical and experimental αK is achieved with the M2+E3 assignment. The result calculated with this assumption is adopted in this evaluation. 6. β+ and electron capture transitions Maximum positron energies were calculated from the adopted Qvalue and the level energies in the 124Te decay daughter, appropriately accounting for the annihilated positron and electron rest masses. Transition probabilities were deduced from the imbalance in total intensities of the γ-rays feeding into and out of each level. Where energetically possible, the relative fractions of β+ and EC decay for each level were calculated with the LOGFT program (based on the work of Gove and Martin 1971), as were the log ft values for each level. Electron capture PK, PL, and PM probabilities were also calculated using the LOGFT program. The calculated β+ endpoint energies and emission rates are compared with published experimental data (Mitchell et al., 1959; Girgis and van Lieshout, 1959; Ruan and Inoue, 1967; Bechvarzh et al., 1970; Woods et al., 1992; and Qaim et al., 2007) in Table 4. The total calculated β+ emission rate calculated in this evaluation is consistent with the most recent experimental data from Qaim et al. (2007), but barely overlaps the value from Woods et al. (1992) at the level of a single uncertainty interval. In general, the currently available experimental 4
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21.62(41) Iβ+,Total+ =
22.1(5) 0.32(9) 753(50) < 0.5
Iβ+,Total+ = 10.59(21) 10.71(25) 2138.3(21) 1543.7(65) 10.9 10.5
Iβ+, % Eβ+,max, keV Iβ+, % Eβ+,max, keV
data are of relatively poor quality and could benefit from new measurements with higher-resolution instrumentation, particularly with regards to the characterization of the two weakest β+ branches and spectral shapes for all the β+ transitions. 7. Conclusion This new evaluation of the decay data for 124I provides new recommended values for the most relevant decay data, including the halflife and energies and emission probabilities for β+ emission, γ-rays, Xrays, conversion electrons, and Auger electrons. By considering six sources of γ-ray emission data in the literature, 3 new levels and 18 γrays were added to the previously-recommended level scheme. The full listing of data, along with a detailed explanation of the evaluation process, is given on the DDEP website.
21.4 Iβ+,Total+ =
790(30)
2136(10) 1520(15)
Iβ+, % Eβ+,max, keV
The author would like to thank Mr. Christophe Dulieu (CEA-LNHB) for his assistance with the SAISINUC program and Dr. Mark Kellett (CEA-LNHB) for his encouragement and patience with this first-time evaluator.
c
b
a
2.2
28.6
786(50)
Iβ+,Total+ =
No uncertainty provided. Calculated from total β+ probability and relative intensities. Authors indicate that intensity is distributed among three levels between 1350 keV and 1248 keV.
26.5(35) Iβ+,Total+ =
13.1 13.3 2130(20) 1531(30)
10.6(2) 11.7(2) 1.9(16) × 10−4 0.293(11) 1.25(10) × 10−4 22.59(28) 0.0 602.7271 1248.5811 1325.5131 1657.283 β+0,0 β+0,1 β+0,2 β+0,3 β+0,4
2137.5(19) 1534.8(19) 888.9(19) 812.0(19) 480.3(19) Iβ+,Total+ =
Iβ+, % Eβ+,max, keV Level, keV Transition
Iβ+, % Eβ+,max, keV
Andersson, G., Rudstam, G., Sörensen, G., 1965. Decay data on some Xe, I, and Te isotopes. Ark. Fys. 28, 37. Bechvarzh, F., Gromov, K.Y., Zhelev, Z.T., Zaitseva, N.G., Loshchilov, M.G., Nazarov, U.K., Sabirov, S.S., 1970. Investigation of the radiation of 124I. Bull. Acad. Sci. USSR Phys. Ser. 33, 1228. Berendakov, S.A., Govor, L.I., Demidov, A.M., Mikhailov, I.V., 1990. Comparison of the de-excitation schemes of the complete system of levels of 122−130Te up to excitation energy 2.5 MeV. Sov. J. Nucl. Phys. 52, 389. Browne, E., 1998. Limitation of Relative Statistical Weights, A Method for Evaluating Discrepant Data. INDC(NDS)−363, Appendix 1. International Atomic Energy Agency, Vienna. Chauvenet, W., 1891. A Manual of Spherical and Practical Astronomy, 5th ed. Lippincott Company, Philadelphia (Appendix). Doll, C., Lehmann, H., Borner, H.G., von Egidy, T., 2000. Lifetime measurement in 124Te. Nucl. Phys. A672, 3. Dulieu, C., Kellett, M.A., Mougeot, X., 2017. Dissemination and visualisation of reference decay data from Decay Data Evaluation Project (DDEP). EPJ Web Conf. 146, 07004. Dyson, N.A., Francois, P.E., 1958. Some observations on the decay of iodine-124 and their implications in radioiodine therapy. Phys. Med. Biol. 3, 111. Ghiҭӑ, D.G., Cata-Danil, G., Bucurescu, D., Cata-Danil, I., Ivascu, M., Mihai, C., Suliman, G., Stroe, L., Sava, T., Zamfir, N.V., 2008. 124Te and the E(5) critical point symmetry. Int. J. Mod. Phys. E17, 1453. Girgis, R.K., van Lieshout, R., 1959. Gamma radiation following the decay of 124Sb and 124 I. Physica 25, 133. Gove, N.B., Martin, M.M., 1971. Log f tables for beta decay. At. Data Nucl. Data Tab. A10, 205. Grigorev, E.P., Zolotavin, A.V., Sergeev, V.O., Sovtsov, M.I., 1969. Bill. Acad. Sci. USSR Phys. Ser. 32, 711. Jentzen, W., Freudenberg, L., Eising, E.G., Sonnenschein, W., Knust, J., Bockisch, A., 2007. Optimized 124I PET dosimetry protocol for radioiodine therapy of differentiated thyroid cancer. J. Nucl. Med. 49, 1017. Jonsson, G.G., Forkman, B., 1968. (γ,xn) reactions in 127I. Nucl. Phys. A107, 52. Karim, H.M., 1973. A study of 4 GeV electron spallation products of iodine. Radiochim. Acta 19, 1. Katakura, J., Wu, Z.D., 2008. Nuclear data sheets for A = 124. Nucl. Data Sheets 109, 1655. Kellett, M.A., Bersillon, O., 2017. The Decay Data Evaluation Project (DDEP) and the JEFF-3.3 radioactive decay data library: combining international collaborative efforts on evaluated decay data. EPJ Web Conf. 146, 02009. Kibédi, T., Burrows, T.W., Trzhaskovskaya, M.B., Davidson, P.M., Nestor Jr., C.W., 2008. Evaluation of theoretical conversion coefficients using BrICC. Nucl. Instrum. Methods Phys. Res. A 589, 202. Koehler, L., Gagnon, K., McQuarrie, S., Wuest, F., 2010. Iodine-124: a promising positron emitter for organic PET chemistry. Molecules 15, 2686. Lagrange, J.-M., 1968. Etude du Schema de Desintegration de l′Iode-124. Compt. Rend. 267B, 1354. Luca, A., Sahagia, M., Ioan, M.-R., Antohe, A., Neascu, B.L., 2016. Experimental determination of some nuclear decay data in the decays of 177Lu, 1886Re, and 124I. Appl. Radiat. Isot. 109, 146–150. Mitchell, A.C.G., Juliano, J.O., Creager, C.B., Kocher, C.W., 1959. Disintegration of 124I and 123I. Phys. Rev. 113, 628. Qaim, S.M., Bisinger, T., Hilgers, K., Nayak, D., Coenen, H.H., 2007. Positron emission intensities in the decay of 64Cu, 76Br, and 124I. Radiochim Acta 95, 67.
800a
11(3) 14(4) 0.5(5)c
2146(15) 1542(20)
Iβ+, % Eβ+,max, keV Iβ+, % Eβ+,max, keV
Ruan and Inoue (1967) Girgis and van Lieshout (1959)
Acknowledgements
References
a
Mitchell et al. (1959) This evaluation
Table 4 Comparison of recommended and experimental β+ endpoint energies, Eβ+,max, and emission probabilities, Iβ+.
a
Bechvarzh et al. (1970)
a
Woods et al. (1992)
b
Qaim et al. (2007)
B.E. Zimmerman
5
Applied Radiation and Isotopes xxx (xxxx) xxx–xxx
B.E. Zimmerman Ragaini, R.C., Walters, W.B., Meyer, R.A., 1969. Levels of 124Te from the decay of 4.2-Day 124 I. Phys. Rev. 187, 1721. Ruan, J.-Z., Inoue, H., 1967. Decay of 124I. J. Phys. Soc. Jpn. 23, 481. Schönfeld, E., Janssen, R., 1996. Evaluation of atomic shell data. Nucl. Instrum. Methods Phys. Res. A 369, 527. Schönfeld, E., Rodloff, G., 1998. Tables of the Energies of K-Auger Electrons for Elements with Atomic Numbers in the Range from Z = 11 to Z = 100, PTB Report PTB-6.1198-1. Schönfeld, E., Rodloff, G., 1999, Energies and Relative Emission Probabilities of K X-rays for Elements with Atomic Numbers in the Range from Z = 5 to Z = 100, PTB Report PTB-6.11-1999-1. Schönfeld, E., Janssen, H., 2000. Calculation of emission probabilities of X-rays and Auger electrons emitted in radioactive disintegration processes. Appl. Radiat. Isot. 52, 595.
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