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Excitation functions of the 165Ho(3He,xn)166,165,163Tm and natTi(3He,x)48V,48Cr reactions
Journal Pre-proof Excitation functions of the reactions
165
3 166,165,163 nat 3 48 48 Ho( He,xn) Tm and Ti( He,x) V, Cr
Ondřej Lebeda, Jan Ráliš, Jan Štursa PII:
S0969-8043(19)31040-1
DOI:
https://doi.org/10.1016/j.apradiso.2019.108988
Reference:
ARI 108988
To appear in:
Applied Radiation and Isotopes
Received Date: 18 September 2019 Revised Date:
29 October 2019
Accepted Date: 13 November 2019
Please cite this article as: Lebeda, Ondř., Ráliš, J., Štursa, J., Excitation functions of the 165 3 166,165,163 nat 3 48 48 Ho( He,xn) Tm and Ti( He,x) V, Cr reactions, Applied Radiation and Isotopes (2019), doi: https://doi.org/10.1016/j.apradiso.2019.108988. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Ltd.
Excitation functions of the 165Ho(3He,xn)166,165,163Tm and natTi(3He,x)48V,48Cr reactions Ondřej Lebeda1, Jan Ráliš, Jan Štursa Nuclear Physics Institute of the CAS, Husinec-Řež 130, 250 68 Řež, Czech Republic Abstract The cross-sections of the natTi(3He,x)48V,48Cr and the 165Ho(3He,xn)166,165,163Tm reactions were measured from the threshold to 47 MeV using well-established method of stacked-foil activation and off-line γ-ray spectrometry. The 3He-ion induced nuclear reaction crosssections on 165Ho were measured for the first time. Their comparison with the prediction adopted from the TENDL-2017 library revealed significant difference. Thick target yields deduced from the experimental data are provided. Key words: cross-sections; He-3 nuclear reactions; Ho-165; Ti-nat; Tm-166; Tm-165; Tm163; V-48; Cr-48; thick target yields 1. Introduction Due to the limited availability of the 3He beams, experimental material on the nuclear reactions induced by this particle is rather scarce. In contrast to proton- and α-induced nuclear reactions, the complex character of the projectile makes prediction of the excitation functions difficult. Thus the measured reaction cross-sections data induced by 3He-ion may contribute to improve the nuclear reaction model codes. We have, therefore, decided to employ 3He beam of the cyclotron U-120M at the Nuclear Physics Institute, Řež for measurement of the excitation functions on naturally monoisotopic elements, where the comparison with theoretical prediction is rather straightforward. In this work, we present cross-sections for the 165Ho(3He,xn) reactions and compare them with the prediction of the TALYS nuclear reaction model code available in the TENDL-2017 library. We further re-measured the natTi(3He,x)48V and natTi(3He,xn)48Cr reaction cross-sections and compare them with previously published data. 2. Experimental 2.1 Target and activation Four stacks of foils containing 8, 8, 3 and 6 Ho discs (99.9 %, 8–11 µm thick, 20 mm diameter, Goodfellow) interleaved with natTi foils (99.6 %, 12.1 µm thick, 20 mm diameter, AlfaAesar) were bombarded with 3He-ions of 28.49, 37.11, 39.72 and 46.92 MeV incident energy on the external beam line of the cyclotron U-120M at the Nuclear Physics Institute of the Czech Academy of Sciences (CAS) in a Faraday-cup-like holder for 1.5–3 hours. The first foil in each stack was Ti monitor followed by the Ho/Ti pairs and finished by 500 µm thick Ag beam stop (99.99 %, Safina, Czech Republic). 1
Corresponding author. E-mail address: [email protected]
The density of the target nuclei per area unit was measured by weighing of each foil and the energy loss and straggling of the 3He beam was calculated with use of the program SRIM (Ziegler et al., SRIM2008). The incident 3He beam energy uncertainty was ca 0.25 MeV (Čihák et al., 2007). Beam current was continuously monitored and integrated over the bombardment time tb. 2.2 Activity measurement Energy and efficiency calibrated γ-ray spectrometers equipped with coaxial HPGe detectors (GMX45-Plus, Ortec; GC2019, Canberra) were employed for the analysis of the activated holmium and titanium foils. The spectrometers were calibrated using a set of point-like standards (241Am, 152Eu, 137Cs, 133Ba and 60Co) for each distance sample-detector used for the measurements. The logarithm of detection efficiency against logarithm of energy was fitted in the whole energy range by a polynomial of the fifth degree, while a linear fit was used for the γ-ray energies exceeding 240 keV. Each stack of was disassembled and the irradiated Ho and Ti foils were subjected to repeated measurements on the γ-ray spectrometers at decreasing distances sample-detector in order to identify and quantify all the present radionuclides with various half-lives and emission probabilities of the γ-lines under optimal conditions. The Ti foils were measured shortly after the EOB in order to quantify 48Cr, and then after the total decay of this radionuclide and that of the 48Sc in order to avoid their interference with the activity of 48V. Attention was paid to the careful quantification of the 48Cr and 48V activity fractions ejected from the monitor to the following Ho foil. The evaluation of the acquired γ-ray spectra was executed in the program DEIMOS (Frána, 2003). All the relevant decay data and the nuclear reaction data used in the evaluation are summarized in Table 1. The decay data were adopted from the NuDat2 database (NuDat2, 2012), and the Q-values and thresholds of the reactions were deduced using the Q-calc program online (Pritychenko and Sonzogni). 2.3 Calculation of cross-sections, their uncertainties, thick target yields and prediction of excitation functions Cross-sections were calculated from the well-known activation formula (equation 1): =
1−
(1 −
)
, (1)
where σ is cross-section for formation of a radionuclide at the energy in the middle of the foil (cm2), Pγ is net peak area of the γ-line used for the radionuclide’s quantification, Iγ is intensity of this γ-line, η is detection efficiency for this γ-line, tm is live time of the measurement (h), tr is real time of measurement (including the dead time) (h), λ is decay constant of a radionuclide (h−1), tc is cooling time between the EOB and the start of the measurement (h), A is atomic weight of the metal foil material (g/mol), z is 3He-ion charge (z = 2), e is elementary
charge (1.602177×10−19 C), d is thickness of the foil (cm), ρ is metal foil density (g/cm3), NA is Avogadro’s number (6.022137×1023 mol−1), I is beam current (A) and tb is irradiation time (h). Total relative cross-section uncertainty was deduced as the square root of the sum of the squares of partial relative uncertainties of the following parameters in the activation formula: • • • • •
detection efficiency for a gamma line selected for the activity calculation (ca 3 %) emission probability of a gamma line used in the activity calculation (usually < 3 %) net peak area of a gamma line selected for the activity calculation (< 10 %) beam current (ca 10 %) foil’s thickness (< 2 %)
There are no reported cross-sections of 3He-induced reaction on 165Ho in the literature. The measured data could be, therefore, compared only with a theoretical prediction. For this purpose, we chose the TALYS nuclear reaction model code, adopting the data directly from the TENDL-2017 library (Koning et al., 2017). 2.4 Interference corrections No interferences were observed in the γ-ray spectra, neither overlapping peaks, nor contribution of the parent nuclei decay. The cross-sections for the formation of 48V were deduced from its activities measured after the total decay of 48Cr, they are, therefore, cumulative regarding this radionuclide. The activity of 48Sc that has common γ-lines with 48V was negligible at the measurement time as well (checked via interference-free 1 037.52 keV γ-line of 48Sc). 3. Results and discussion 3.1 Beam energy and current We haven’t corrected neither incident beam energy, nor the beam current for any of the four bombarded stack of foils. In the calculations, we used the beam incident energies as set and the beam energy loss in the stack deduced from the stopping power, and the recorded beam currents. The measured cross-sections of the monitoring reaction natTi(3He,x)48V were compared with the recommended values (Hermanne et al., 2018), see subsection 3.2.1. 3.2 Measured cross-sections and prediction of excitation functions The measured excitation functions data together with the previously published data (if available) and prediction of the TALYS code are displayed in Figs. 1,2,4–6. The numerical values including the uncertainties are summarized in Table 2 and in Table 3. 3.2.1 Cross-sections for the natTi(3He,x)48V reactions The activity of 48V was calculated as a weighted average value deduced from the net photopeak area of both its dominant γ-rays indicated in Table 1 that provide almost identical
results. The spectra acquired after the total decay of 48Cr and almost complete decay of 48Sc were used for its quantification. The measured experimental cross-sections are summarized in Table 2. Their comparison with the recommended values (Hermanne et al., 2018), and with all the previously measured data (Weinreich et al., 1980, Tárkányi et al., 1992, Ditrói et al., 2000 and Szelecsényi et al., 2017) is displayed in Fig. 1. All the cross-sections agree within indicated uncertainties as well as with the recently recommended data. The best agreement was observed with the recent measurement of Szelecsényi et al. (2017), in particular for the energies exceeding 35 MeV, where the data of Weinreich et al. (1980) seem to be systematically slightly lower. Significant amount of 48V is ejected from the titanium foil to the following Ho foil in the stack. This fraction was thoroughly measured and summed with the 48V activity in the Ti disc itself prior cross-section calculation. The ejected fraction as a function of energy is displayed in Fig. 3. It slowly grows from 3.4 % at 14 MeV to ca 6.5 % for energies exceeding 36 MeV, where it becomes to be roughly constant. 3.2.2 Cross-sections for the natTi(3He,xn)48Cr reactions Radionuclide 48Cr was quantified via its second dominant 308.24 keV γ-line (100 % per decay). The obtained cross-sections are summarized in Table 2 and compared with three published experimental data sets (Weinreich et al., 1980, Ditrói et al., 2000 and Szelecsényi et al., 2017) in Fig. 2. Our results agree very well with the measurement of Ditrói et al. (2000) and Szelecsényi et al. (2017), while the data of Weinreich et al. (1980) are in general slightly lower, although the difference hardly exceed the estimated uncertainties of both measurements. Due to its shape and rapid, straightforward quantification of 48Cr shortly after the end of bombardment, the natTi(3He,xn)48Cr may serve as the second 3He beam monitoring reaction on natural titanium. Similar to 48V, we measured always the ejected fraction of 48Cr from the Ti foils. Results displayed in Fig. 3 demonstrate again gradual increase of this fraction with energy, the data are however more scattered than in the case of 48V, reaching maximum of 8.8 % at 41 MeV. 3.2.3 Cross-sections for the 165Ho(3He,2n)166Tm reaction Activity of the radionuclide 166Tm was measured via its strongest γ-line 778.814 keV (emission probability 19.1 % per decay). The deduced cross-sections and their uncertainties are provided in Table 3 and displayed in Fig. 4 together with the TALYS prediction adopted from the TENDL-2017 library. The TALYS suggests similar shape of the excitation function as the measured data, but it underestimates them approximately five times. Position of the maximum derived from the experimental data is at 20 MeV, while TALYS is shifted by 4 MeV towards higher energy. 3.2.4 Cross-sections for the 165Ho(3He,3n)165Tm reaction The longer-lived 165Tm was quantified via its dominant 242.917 keV γ-line with emission probability of 35.5 % per decay present in the spectra acquired after the total decay of 163Tm that emits an interfering 241.3 keV γ-line (cf. Table 1). The resulting cross-sections are
summarized in Table 3 and shown in Fig. 5. The TALYS code indicates significantly less rapid decrease of the excitation function following the maximum that is again forecast at much higher energy (25 MeV experiment versus 30 MeV theory). The predicted cross-section values significantly underestimate the experimental data (by a factor of 30 at the maximum), too. 3.2.5 Cross-sections for the 165Ho(3He,5n)163Tm reaction Activity of the short-lived 163Tm was based on its 1 265.116 keV γ-line (emission probability of 5.17 % per decay). It shows very good agreement with other 163Tm γ-rays in the spectrum, and although not the strongest, good counting statistics was obtained at low background levels at the peak position. The measured cross-sections are summarized in Table 3 and represented in Fig. 6 together with the values from the theoretical model. The forecast of the TALYS code as adopted from the TENDL-2017 library follows well the shape of the experimental excitation function, but the absolute values underestimate the experiment roughly by a factor of 40. This radionuclide allowed us to estimate the fraction of the reaction product ejected on the following titanium foil in the stack thanks to the high activity formed in the holmium foils. As expected from the larger mass of the formed nucleus, this fraction is practically negligible compared to that of 48V or 48Cr, reaching 1.5 % at the highest energy of 46.5 MeV. 3.4 Thick target yields The production rate (thick target yield) for 166Tm, 165Tm and 163Tm was calculated from the measured cross-sections (Otuka and Takács, 2015). The data were fitted with one or two polynomials and the fit was integrated employing the stopping power of 3He in holmium adopted from the SRIM2008 program. The thick target yields are displayed in Figs. 7–9. Conclusion We measured the excitation functions of the 165Ho(3He,xn)166,165,163Tm nuclear reactions for the first time. The comparison of the experimental results with the predictions of the TALYS nuclear reaction model code revealed differences that are far from an acceptable agreement. The obtained data may serve as a benchmark in further improvement of the nuclear reaction model codes for 3He-induced nuclear reactions. We also provide new cross-sections for the reactions of 3He on natTi resulting in 48V and 48Cr. Both of them are relevant in the 3He beam monitoring. Since the experimental material for these reactions is rather scarce, supplying new data is desirable for revising the recommended cross-sections. Acknowledgement The work was supported by the IAEA Research Contract No. 16667 and by the research plan RVO61389005 of the Nuclear Physics Institute of the Czech Academy of Sciences. References
Čihák, M., Lebeda, O., Štursa, J., 2007. Beam dynamic simulation in the isochronous cyclotron U120M. In: Proceedings of the eighteenth international conference on cyclotrons and their applications, CYCLOTRONS 2007, Giardini Naxos, Italy, 2007. Ditrói, F., Tárkányi, F., Ali, M.A., Ando, L., Heselius, S.J., Shubin, Yu., Youxiang, Z., Mustafa, M.G., 2000. Investigation of 3He-induced reactions on natural Ti for nuclear analytical and radionuclide production purposes. Nucl. Inst. Methods in Phys. Res. B 168(3), 337–346. Frána, J., 2003. Program DEIMOS32 for gamma-ray spectra evaluation. J. Radioanal. Nucl. Chem. 257(3), 583–587. Hermanne, A., Ignatyuk, A.V., Capote, R., Carlson, B.V., Engle, J.W., Kellett, M.A., Kibedi, T., Kim, G., Kondev, F.G., Hussain, M., Lebeda, O., Luca, A., Nagai, Y., Naik, H., Nichols, A.L., Nortier, F.M., Suryanarayana, S. V., Takacs, S., Tárkányi, F.T., Verpelli, M., 2018. Reference Cross Sections for Charged-particle Monitor Reactions. Nuclear Data Sheets 148, 338–382. Data available from URL:. Lebeda, O., Lozza, V., Schrock, P., Štursa, J., Zuber, K., 2012. Excitation functions of proton-induced reactions on natural Nd in the 10–30 MeV energy range, and production of radionuclides relevant for double-β decay. Phys. Rev. C 85(1), 014602, 12 pages. NuDat 2.6, National Nuclear Data Center, Brookhaven National Laboratory, 2012. Available at URL . Szelecsényi, F., Kovács, Z., Nagatsu, K., Zhang, M.-R., Suzuki, K., 2017. Production cross sections of radioisotopes from 3He-particle induced nuclear reactions on natural titanium. Appl. Radiat. Isot. 119, 94–100. Tárkányi, F., Szelecsényi, F., Kopecký, P., 1992. Cross section data for proton, He-3 and alphaparticle induced reactions on natNi, natCu and natTi for monitoring beam performance. In: Qaim, M., (Ed.) Proceedings of International Conference on Nuclear Data for Science and Technology. Juelich, Germany, 13–17 May 1991, Springer-Verlag, pp. 529–532. Weinreich, R., Probst, H.J., Qaim, S.M., 1980. Production of chromium-48 for applications in life sciences. Int. J. Appl. Radiat. Isot. 31(4), 223–232. Ziegler, J.F., Ziegler,
M.D.,
Biersack,
J.P.
SRIM2008
Code,
Available
at
URL
Radionuclide
Half-life
Reaction
Q (MeV)
Threshold (MeV)
166
Tm
7.70 h 3
165
Ho(3He,2n)
−4.222
4.299
165
Tm
30.06 h 3
165
Ho(3He,3n)
−11.252
11.458
163
Tm
1.810 h 5
165
Ho(3He,5n)
−27.596
28.100
7.992 −0.889 −12.515 −20.658 −31.597 5.554 −3.327 −14.953 −23.096 −34.035
0 0.946 13.303 21.931 33.505 0 3.540 15.894 24.519 36.090
46
Ti(3He,p) Ti(3He,pn) 48 Ti(3He,p2n) 49 Ti(3He,p3n) 50 Ti(3He,p4n) 46 Ti(3He,n) 47 Ti(3He,2n) 48 Ti(3He,3n) 49 Ti(3He,4n) 50 Ti(3He,5n) 47
48
48
V
Cr
15.9735 d 25
21.56 h 3
Eγ (keV) 184.405 25 705.333 20 778.814 15 785.904 15 1 273.540 16 242.917 7 297.369 6 806.372 17 104.320 3 241.305 5 1 265.116 25 1 397.52 3 1 434.45 3 944.130 4 983.525 4 1 312.106 8
Iγ (%) 16.2 10 11.1 7 19.1 12 10.0 6 17.4 11 35.5 17 12.7 6 9.5 5 18.6 6 10.9 4 5.17 17 7.03 24 8.0 3 7.870 7 99.98 4 98.2 3
112.31 8 308.24 6
96.0 20 100
Table 1 Data for the quantified radionuclides. Q-values for reactions where composed particles are emitted need to be increased by binding energy of the particle (d = np + 2.225 MeV, t = p2n + 8.482 MeV, 3He = 2pn + 7.718 MeV, α = 2p2n + 28.296 MeV). Energies and emission probabilities of γlines used for quantification of a radionuclide’s activity are in bold. Uncertainties in the last digits are displayed in italics.
EHe-3 (MeV) 28.41 ± 0.26 26.27 ± 0.32 24.89 ± 0.36 23.43 ± 0.41 20.13 ± 0.53 18.21 ± 0.61 16.12 ± 0.71 13.83 ± 0.84 37.09 ± 0.26 35.16 ± 0.31 33.86 ± 0.34 32.53 ± 0.38 31.19 ± 0.42 30.00 ± 0.45 28.56 ± 0.50 27.11 ± 0.55 25.77 ± 0.60 39.71 ± 0.26 37.34 ± 0.32 36.25 ± 0.35 46.93 ± 0.26 45.42 ± 0.29 44.35 ± 0.32 43.26 ± 0.35 41.18 ± 0.40
σ (mb) 48
V 401 ± 43 358 ± 38 315 ± 34 266 ± 29 139 ± 15 91.1 ± 9.8 65.8 ± 7.1 60.5 ± 6.5 359 ± 38 387 ± 41 402 ± 43 411 ± 44 416 ± 45 414 ± 44 402 ± 43 379 ± 41 346 ± 37 323 ± 35 350 ± 38 372 ± 40 222 ± 24 230 ± 25 243 ± 26 262 ± 28 289 ± 31
48
Cr 8.53 ± 0.91 7.43 ± 0.79 6.52 ± 0.70 5.55 ± 0.59 3.69 ± 0.39 3.11 ± 0.33 3.00 ± 0.32 2.95 ± 0.32 8.13 ± 0.87 9.12 ± 0.98 9.41 ± 1.01 9.73 ± 1.04 9.67 ± 1.04 9.38 ± 1.00 8.87 ± 0.95 7.90 ± 0.85 7.11 ± 0.76 6.80 ± 0.74 8.05 ± 0.87 8.73 ± 0.94 4.00 ± 0.43 4.33 ± 0.47 4.60 ± 0.50 5.06 ± 0.55 6.07 ± 0.65
Table 2 Experimental cross-sections for the formation of 48V and 48Cr in the 165Ho(3He,x) reactions
EHe-3 (MeV) 26.94 ± 0.30 25.59 ± 0.34 24.17 ± 0.38 22.67 ± 0.43 20.94 ± 0.49 19.19 ± 0.56 17.19 ± 0.65 15.00 ± 0.77 35.80 ± 0.29 34.51 ± 0.32 33.20 ± 0.36 31.87 ± 0.40 30.60 ± 0.44 29.29 ± 0.48 27.85 ± 0.52 26.45 ± 0.57 39.12 ± 0.27 37.89 ± 0.30 36.80 ± 0.33 46.46 ± 0.27 44.89 ± 0.31 43.81 ± 0.33 42.76 ± 0.36 41.68 ± 0.39 40.58 ± 0.42
166
Tm 23.1 ± 2.9 24.7 ± 3.1 27.1 ± 3.3 28.6 ± 3.5 31.0 ± 3.8 31.1 ± 3.8 23.7 ± 2.9 8.1 ± 1.0 15.2 ± 1.9 14.8 ± 1.8 15.7 ± 2.0 18.6 ± 2.3 18.9 ± 2.4 19.6 ± 2.4 21.0 ± 2.6 22.6 ± 2.8 12.2 ± 1.5 13.3 ± 1.7 14.3 ± 1.9 8.6 ± 1.1 9.2 ± 1.2 9.7 ± 1.2 10.7 ± 1.3 11.2 ± 1.3 11.5 ± 1.3
σ (mb) 165 Tm 507 ± 58 577 ± 67 587 ± 68 504 ± 58 361 ± 42 205 ± 24 69.2 ± 8.0 7.69 ± 0.89 121 ± 14 139 ± 16 164 ± 19 208 ± 24 257 ± 30 318 ± 37 404 ± 47 489 ± 56 88 ± 10 99 ± 11 115 ± 13 51.2 ± 5.9 55.3 ± 6.4 59.3 ± 6.8 64.7 ± 7.5 69.5 ± 8.0 74.5 ± 8.6
163
Tm
184 ± 20 93 ± 10 38.3 ± 4.3 10.7 ± 1.3 1.67 ± 0.34
434 ± 48 319 ± 35 235 ± 26 897 ± 100 857 ± 95 819 ± 91 768 ± 86 698 ± 78 584 ± 66
Table 3 Experimental cross-sections for the formation of 166,165,163Tm in the 165Ho(3He,xn) reactions
500 natTi(3He,x)48V 450 This work Weinreich (1980) Tárkányi (1992) Ditrói (2000) Szelecsényi (2017) IAEA recommended
400
cross-section (mb)
350 300 250 200 150 100 50 0 0
10
20
30
40
50
60
70
EHe-3 (MeV)
Fig. 1 Re-measured excitation function of the monitoring reaction natTi(3He,x)48V – our cross-sections in comparison with the previously published results of Weinreich et al. (1980), Tárkányi et al. (1992), Ditrói et al. (2000) and Szelecsényi et al. (2017) and with the IAEA recommended data (Hermanne et al., 2018)
12 natTi(3He,x)48Cr
This work
10
Weinreich (1980)
cross-section (mb)
Ditrói (2000) Szelecsényi (2017)
8
6
4
2
0 0
10
20
30
40
50
60
70
EHe-3 (MeV)
Fig. 2 Excitation function of the natTi(3He,xn)48Cr reaction – our data in comparison with the previously published results of Weinreich et al. (1980), Ditrói et al. (2000) and Szelecsényi et al. (2017)
10
V-48 Cr-48
9
ejected activity (%)
8 7 6 5 4 3 2 1 0 0
10
20 3He
30
40
50
energy (MeV)
Fig. 3 Fraction of the 48V and 48Cr ejected from the monitoring stack as a function of energy
nat
Ti foil to the following foil in the
7
165Ho( 3He,2n)166Tm
35
6
This work
30
TENDL-2017
5
25 4 20 3 15 2
10 5
1
0
0 10
15
20
25 3He
30
35
40
45
predicted cross-section (mb)
experimental cross-section (mb)
40
50
energy (MeV)
Fig. 4 Cross-sections of the 165Ho(3He,2n)166Tm reaction – the measured values in comparison with the TALYS prediction adopted from the TENDL-2017 library
25
165Ho( 3He,3n) 165Tm
This work
600
TENDL-2017
20
500 15
400 300
10
200 5 100 0
predicted cross-section (mb)
experimental cross-section (mb)
700
0 10
15
20
25 3He
30
35
40
45
50
energy (MeV)
Fig. 5 Cross-sections of the 165Ho(3He,3n)165Tm reaction – the measured values in comparison with the TALYS prediction adopted from the TENDL-2017 library
25
165Ho(3He,5n)163Tm
800
20
600
15
400
10 This work
200
5
TENDL-2017
0
predicted cross-section (mb)
experimental cross-section (mb)
1000
0 30
32
34
36
38 3He
40
42
44
46
48
50
energy (MeV)
Fig. 6 Cross-sections of the 165Ho(3He,5n)163Tm reaction – the measured values in comparison with the TALYS prediction adopted from the TENDL-2017 library
8
165Ho( 3He,2n) 166Tm
production rate (MBq/µAh)
7 6 5 4 3 2 1 0 15
20
25
30 3He
35
40
energy (MeV)
Fig. 7 Thick target yield (production rate) for 166Tm in the 165Ho(3He,2n) reaction
45
production rate (MBq/µAh)
25
165Ho( 3He,3n) 165Tm
20
15
10
5
0 15
20
25
30 3He
35
40
energy (MeV)
Fig. 8 Thick target yield (production rate) for 165Tm in the 165Ho(3He,3n) reaction
45
50
production rate (MBq/µAh)
600
165Ho( 3He,5n) 163Tm
500
400
300
200
100
0 30
32
34
36
38 3He
40
42
44
46
energy (MeV)
Fig. 9 Thick target yield (production rate) for 163Tm in the 165Ho(3He,5n) reaction
48
50
Highlights The first measurement of the cross-sections for the (3He,xn) nuclear reactions on 165Ho. Benchmark for the prediction of 3He-induced nuclear reaction cross-sections in nuclear reaction model codes. New cross-sections for the monitoring reaction natTi(3He,x)48V are provided. New cross-sections for the potential monitoring reaction natTi(3He,x)48Cr were measured.
Declaration of interests ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. ☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:
Ondřej Lebeda Jan Ráliš Jan Štursa
165
3 166,165,163 nat 3 48 48 Ho( He,xn) Tm and Ti( He,x) V, Cr
Ondřej Lebeda, Jan Ráliš, Jan Štursa PII:
S0969-8043(19)31040-1
DOI:
https://doi.org/10.1016/j.apradiso.2019.108988
Reference:
ARI 108988
To appear in:
Applied Radiation and Isotopes
Received Date: 18 September 2019 Revised Date:
29 October 2019
Accepted Date: 13 November 2019
Please cite this article as: Lebeda, Ondř., Ráliš, J., Štursa, J., Excitation functions of the 165 3 166,165,163 nat 3 48 48 Ho( He,xn) Tm and Ti( He,x) V, Cr reactions, Applied Radiation and Isotopes (2019), doi: https://doi.org/10.1016/j.apradiso.2019.108988. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Ltd.
Excitation functions of the 165Ho(3He,xn)166,165,163Tm and natTi(3He,x)48V,48Cr reactions Ondřej Lebeda1, Jan Ráliš, Jan Štursa Nuclear Physics Institute of the CAS, Husinec-Řež 130, 250 68 Řež, Czech Republic Abstract The cross-sections of the natTi(3He,x)48V,48Cr and the 165Ho(3He,xn)166,165,163Tm reactions were measured from the threshold to 47 MeV using well-established method of stacked-foil activation and off-line γ-ray spectrometry. The 3He-ion induced nuclear reaction crosssections on 165Ho were measured for the first time. Their comparison with the prediction adopted from the TENDL-2017 library revealed significant difference. Thick target yields deduced from the experimental data are provided. Key words: cross-sections; He-3 nuclear reactions; Ho-165; Ti-nat; Tm-166; Tm-165; Tm163; V-48; Cr-48; thick target yields 1. Introduction Due to the limited availability of the 3He beams, experimental material on the nuclear reactions induced by this particle is rather scarce. In contrast to proton- and α-induced nuclear reactions, the complex character of the projectile makes prediction of the excitation functions difficult. Thus the measured reaction cross-sections data induced by 3He-ion may contribute to improve the nuclear reaction model codes. We have, therefore, decided to employ 3He beam of the cyclotron U-120M at the Nuclear Physics Institute, Řež for measurement of the excitation functions on naturally monoisotopic elements, where the comparison with theoretical prediction is rather straightforward. In this work, we present cross-sections for the 165Ho(3He,xn) reactions and compare them with the prediction of the TALYS nuclear reaction model code available in the TENDL-2017 library. We further re-measured the natTi(3He,x)48V and natTi(3He,xn)48Cr reaction cross-sections and compare them with previously published data. 2. Experimental 2.1 Target and activation Four stacks of foils containing 8, 8, 3 and 6 Ho discs (99.9 %, 8–11 µm thick, 20 mm diameter, Goodfellow) interleaved with natTi foils (99.6 %, 12.1 µm thick, 20 mm diameter, AlfaAesar) were bombarded with 3He-ions of 28.49, 37.11, 39.72 and 46.92 MeV incident energy on the external beam line of the cyclotron U-120M at the Nuclear Physics Institute of the Czech Academy of Sciences (CAS) in a Faraday-cup-like holder for 1.5–3 hours. The first foil in each stack was Ti monitor followed by the Ho/Ti pairs and finished by 500 µm thick Ag beam stop (99.99 %, Safina, Czech Republic). 1
Corresponding author. E-mail address: [email protected]
The density of the target nuclei per area unit was measured by weighing of each foil and the energy loss and straggling of the 3He beam was calculated with use of the program SRIM (Ziegler et al., SRIM2008). The incident 3He beam energy uncertainty was ca 0.25 MeV (Čihák et al., 2007). Beam current was continuously monitored and integrated over the bombardment time tb. 2.2 Activity measurement Energy and efficiency calibrated γ-ray spectrometers equipped with coaxial HPGe detectors (GMX45-Plus, Ortec; GC2019, Canberra) were employed for the analysis of the activated holmium and titanium foils. The spectrometers were calibrated using a set of point-like standards (241Am, 152Eu, 137Cs, 133Ba and 60Co) for each distance sample-detector used for the measurements. The logarithm of detection efficiency against logarithm of energy was fitted in the whole energy range by a polynomial of the fifth degree, while a linear fit was used for the γ-ray energies exceeding 240 keV. Each stack of was disassembled and the irradiated Ho and Ti foils were subjected to repeated measurements on the γ-ray spectrometers at decreasing distances sample-detector in order to identify and quantify all the present radionuclides with various half-lives and emission probabilities of the γ-lines under optimal conditions. The Ti foils were measured shortly after the EOB in order to quantify 48Cr, and then after the total decay of this radionuclide and that of the 48Sc in order to avoid their interference with the activity of 48V. Attention was paid to the careful quantification of the 48Cr and 48V activity fractions ejected from the monitor to the following Ho foil. The evaluation of the acquired γ-ray spectra was executed in the program DEIMOS (Frána, 2003). All the relevant decay data and the nuclear reaction data used in the evaluation are summarized in Table 1. The decay data were adopted from the NuDat2 database (NuDat2, 2012), and the Q-values and thresholds of the reactions were deduced using the Q-calc program online (Pritychenko and Sonzogni). 2.3 Calculation of cross-sections, their uncertainties, thick target yields and prediction of excitation functions Cross-sections were calculated from the well-known activation formula (equation 1): =
1−
(1 −
)
, (1)
where σ is cross-section for formation of a radionuclide at the energy in the middle of the foil (cm2), Pγ is net peak area of the γ-line used for the radionuclide’s quantification, Iγ is intensity of this γ-line, η is detection efficiency for this γ-line, tm is live time of the measurement (h), tr is real time of measurement (including the dead time) (h), λ is decay constant of a radionuclide (h−1), tc is cooling time between the EOB and the start of the measurement (h), A is atomic weight of the metal foil material (g/mol), z is 3He-ion charge (z = 2), e is elementary
charge (1.602177×10−19 C), d is thickness of the foil (cm), ρ is metal foil density (g/cm3), NA is Avogadro’s number (6.022137×1023 mol−1), I is beam current (A) and tb is irradiation time (h). Total relative cross-section uncertainty was deduced as the square root of the sum of the squares of partial relative uncertainties of the following parameters in the activation formula: • • • • •
detection efficiency for a gamma line selected for the activity calculation (ca 3 %) emission probability of a gamma line used in the activity calculation (usually < 3 %) net peak area of a gamma line selected for the activity calculation (< 10 %) beam current (ca 10 %) foil’s thickness (< 2 %)
There are no reported cross-sections of 3He-induced reaction on 165Ho in the literature. The measured data could be, therefore, compared only with a theoretical prediction. For this purpose, we chose the TALYS nuclear reaction model code, adopting the data directly from the TENDL-2017 library (Koning et al., 2017). 2.4 Interference corrections No interferences were observed in the γ-ray spectra, neither overlapping peaks, nor contribution of the parent nuclei decay. The cross-sections for the formation of 48V were deduced from its activities measured after the total decay of 48Cr, they are, therefore, cumulative regarding this radionuclide. The activity of 48Sc that has common γ-lines with 48V was negligible at the measurement time as well (checked via interference-free 1 037.52 keV γ-line of 48Sc). 3. Results and discussion 3.1 Beam energy and current We haven’t corrected neither incident beam energy, nor the beam current for any of the four bombarded stack of foils. In the calculations, we used the beam incident energies as set and the beam energy loss in the stack deduced from the stopping power, and the recorded beam currents. The measured cross-sections of the monitoring reaction natTi(3He,x)48V were compared with the recommended values (Hermanne et al., 2018), see subsection 3.2.1. 3.2 Measured cross-sections and prediction of excitation functions The measured excitation functions data together with the previously published data (if available) and prediction of the TALYS code are displayed in Figs. 1,2,4–6. The numerical values including the uncertainties are summarized in Table 2 and in Table 3. 3.2.1 Cross-sections for the natTi(3He,x)48V reactions The activity of 48V was calculated as a weighted average value deduced from the net photopeak area of both its dominant γ-rays indicated in Table 1 that provide almost identical
results. The spectra acquired after the total decay of 48Cr and almost complete decay of 48Sc were used for its quantification. The measured experimental cross-sections are summarized in Table 2. Their comparison with the recommended values (Hermanne et al., 2018), and with all the previously measured data (Weinreich et al., 1980, Tárkányi et al., 1992, Ditrói et al., 2000 and Szelecsényi et al., 2017) is displayed in Fig. 1. All the cross-sections agree within indicated uncertainties as well as with the recently recommended data. The best agreement was observed with the recent measurement of Szelecsényi et al. (2017), in particular for the energies exceeding 35 MeV, where the data of Weinreich et al. (1980) seem to be systematically slightly lower. Significant amount of 48V is ejected from the titanium foil to the following Ho foil in the stack. This fraction was thoroughly measured and summed with the 48V activity in the Ti disc itself prior cross-section calculation. The ejected fraction as a function of energy is displayed in Fig. 3. It slowly grows from 3.4 % at 14 MeV to ca 6.5 % for energies exceeding 36 MeV, where it becomes to be roughly constant. 3.2.2 Cross-sections for the natTi(3He,xn)48Cr reactions Radionuclide 48Cr was quantified via its second dominant 308.24 keV γ-line (100 % per decay). The obtained cross-sections are summarized in Table 2 and compared with three published experimental data sets (Weinreich et al., 1980, Ditrói et al., 2000 and Szelecsényi et al., 2017) in Fig. 2. Our results agree very well with the measurement of Ditrói et al. (2000) and Szelecsényi et al. (2017), while the data of Weinreich et al. (1980) are in general slightly lower, although the difference hardly exceed the estimated uncertainties of both measurements. Due to its shape and rapid, straightforward quantification of 48Cr shortly after the end of bombardment, the natTi(3He,xn)48Cr may serve as the second 3He beam monitoring reaction on natural titanium. Similar to 48V, we measured always the ejected fraction of 48Cr from the Ti foils. Results displayed in Fig. 3 demonstrate again gradual increase of this fraction with energy, the data are however more scattered than in the case of 48V, reaching maximum of 8.8 % at 41 MeV. 3.2.3 Cross-sections for the 165Ho(3He,2n)166Tm reaction Activity of the radionuclide 166Tm was measured via its strongest γ-line 778.814 keV (emission probability 19.1 % per decay). The deduced cross-sections and their uncertainties are provided in Table 3 and displayed in Fig. 4 together with the TALYS prediction adopted from the TENDL-2017 library. The TALYS suggests similar shape of the excitation function as the measured data, but it underestimates them approximately five times. Position of the maximum derived from the experimental data is at 20 MeV, while TALYS is shifted by 4 MeV towards higher energy. 3.2.4 Cross-sections for the 165Ho(3He,3n)165Tm reaction The longer-lived 165Tm was quantified via its dominant 242.917 keV γ-line with emission probability of 35.5 % per decay present in the spectra acquired after the total decay of 163Tm that emits an interfering 241.3 keV γ-line (cf. Table 1). The resulting cross-sections are
summarized in Table 3 and shown in Fig. 5. The TALYS code indicates significantly less rapid decrease of the excitation function following the maximum that is again forecast at much higher energy (25 MeV experiment versus 30 MeV theory). The predicted cross-section values significantly underestimate the experimental data (by a factor of 30 at the maximum), too. 3.2.5 Cross-sections for the 165Ho(3He,5n)163Tm reaction Activity of the short-lived 163Tm was based on its 1 265.116 keV γ-line (emission probability of 5.17 % per decay). It shows very good agreement with other 163Tm γ-rays in the spectrum, and although not the strongest, good counting statistics was obtained at low background levels at the peak position. The measured cross-sections are summarized in Table 3 and represented in Fig. 6 together with the values from the theoretical model. The forecast of the TALYS code as adopted from the TENDL-2017 library follows well the shape of the experimental excitation function, but the absolute values underestimate the experiment roughly by a factor of 40. This radionuclide allowed us to estimate the fraction of the reaction product ejected on the following titanium foil in the stack thanks to the high activity formed in the holmium foils. As expected from the larger mass of the formed nucleus, this fraction is practically negligible compared to that of 48V or 48Cr, reaching 1.5 % at the highest energy of 46.5 MeV. 3.4 Thick target yields The production rate (thick target yield) for 166Tm, 165Tm and 163Tm was calculated from the measured cross-sections (Otuka and Takács, 2015). The data were fitted with one or two polynomials and the fit was integrated employing the stopping power of 3He in holmium adopted from the SRIM2008 program. The thick target yields are displayed in Figs. 7–9. Conclusion We measured the excitation functions of the 165Ho(3He,xn)166,165,163Tm nuclear reactions for the first time. The comparison of the experimental results with the predictions of the TALYS nuclear reaction model code revealed differences that are far from an acceptable agreement. The obtained data may serve as a benchmark in further improvement of the nuclear reaction model codes for 3He-induced nuclear reactions. We also provide new cross-sections for the reactions of 3He on natTi resulting in 48V and 48Cr. Both of them are relevant in the 3He beam monitoring. Since the experimental material for these reactions is rather scarce, supplying new data is desirable for revising the recommended cross-sections. Acknowledgement The work was supported by the IAEA Research Contract No. 16667 and by the research plan RVO61389005 of the Nuclear Physics Institute of the Czech Academy of Sciences. References
Čihák, M., Lebeda, O., Štursa, J., 2007. Beam dynamic simulation in the isochronous cyclotron U120M. In: Proceedings of the eighteenth international conference on cyclotrons and their applications, CYCLOTRONS 2007, Giardini Naxos, Italy, 2007. Ditrói, F., Tárkányi, F., Ali, M.A., Ando, L., Heselius, S.J., Shubin, Yu., Youxiang, Z., Mustafa, M.G., 2000. Investigation of 3He-induced reactions on natural Ti for nuclear analytical and radionuclide production purposes. Nucl. Inst. Methods in Phys. Res. B 168(3), 337–346. Frána, J., 2003. Program DEIMOS32 for gamma-ray spectra evaluation. J. Radioanal. Nucl. Chem. 257(3), 583–587. Hermanne, A., Ignatyuk, A.V., Capote, R., Carlson, B.V., Engle, J.W., Kellett, M.A., Kibedi, T., Kim, G., Kondev, F.G., Hussain, M., Lebeda, O., Luca, A., Nagai, Y., Naik, H., Nichols, A.L., Nortier, F.M., Suryanarayana, S. V., Takacs, S., Tárkányi, F.T., Verpelli, M., 2018. Reference Cross Sections for Charged-particle Monitor Reactions. Nuclear Data Sheets 148, 338–382. Data available from URL:
M.D.,
Biersack,
J.P.
SRIM2008
Code,
Available
at
URL
Radionuclide
Half-life
Reaction
Q (MeV)
Threshold (MeV)
166
Tm
7.70 h 3
165
Ho(3He,2n)
−4.222
4.299
165
Tm
30.06 h 3
165
Ho(3He,3n)
−11.252
11.458
163
Tm
1.810 h 5
165
Ho(3He,5n)
−27.596
28.100
7.992 −0.889 −12.515 −20.658 −31.597 5.554 −3.327 −14.953 −23.096 −34.035
0 0.946 13.303 21.931 33.505 0 3.540 15.894 24.519 36.090
46
Ti(3He,p) Ti(3He,pn) 48 Ti(3He,p2n) 49 Ti(3He,p3n) 50 Ti(3He,p4n) 46 Ti(3He,n) 47 Ti(3He,2n) 48 Ti(3He,3n) 49 Ti(3He,4n) 50 Ti(3He,5n) 47
48
48
V
Cr
15.9735 d 25
21.56 h 3
Eγ (keV) 184.405 25 705.333 20 778.814 15 785.904 15 1 273.540 16 242.917 7 297.369 6 806.372 17 104.320 3 241.305 5 1 265.116 25 1 397.52 3 1 434.45 3 944.130 4 983.525 4 1 312.106 8
Iγ (%) 16.2 10 11.1 7 19.1 12 10.0 6 17.4 11 35.5 17 12.7 6 9.5 5 18.6 6 10.9 4 5.17 17 7.03 24 8.0 3 7.870 7 99.98 4 98.2 3
112.31 8 308.24 6
96.0 20 100
Table 1 Data for the quantified radionuclides. Q-values for reactions where composed particles are emitted need to be increased by binding energy of the particle (d = np + 2.225 MeV, t = p2n + 8.482 MeV, 3He = 2pn + 7.718 MeV, α = 2p2n + 28.296 MeV). Energies and emission probabilities of γlines used for quantification of a radionuclide’s activity are in bold. Uncertainties in the last digits are displayed in italics.
EHe-3 (MeV) 28.41 ± 0.26 26.27 ± 0.32 24.89 ± 0.36 23.43 ± 0.41 20.13 ± 0.53 18.21 ± 0.61 16.12 ± 0.71 13.83 ± 0.84 37.09 ± 0.26 35.16 ± 0.31 33.86 ± 0.34 32.53 ± 0.38 31.19 ± 0.42 30.00 ± 0.45 28.56 ± 0.50 27.11 ± 0.55 25.77 ± 0.60 39.71 ± 0.26 37.34 ± 0.32 36.25 ± 0.35 46.93 ± 0.26 45.42 ± 0.29 44.35 ± 0.32 43.26 ± 0.35 41.18 ± 0.40
σ (mb) 48
V 401 ± 43 358 ± 38 315 ± 34 266 ± 29 139 ± 15 91.1 ± 9.8 65.8 ± 7.1 60.5 ± 6.5 359 ± 38 387 ± 41 402 ± 43 411 ± 44 416 ± 45 414 ± 44 402 ± 43 379 ± 41 346 ± 37 323 ± 35 350 ± 38 372 ± 40 222 ± 24 230 ± 25 243 ± 26 262 ± 28 289 ± 31
48
Cr 8.53 ± 0.91 7.43 ± 0.79 6.52 ± 0.70 5.55 ± 0.59 3.69 ± 0.39 3.11 ± 0.33 3.00 ± 0.32 2.95 ± 0.32 8.13 ± 0.87 9.12 ± 0.98 9.41 ± 1.01 9.73 ± 1.04 9.67 ± 1.04 9.38 ± 1.00 8.87 ± 0.95 7.90 ± 0.85 7.11 ± 0.76 6.80 ± 0.74 8.05 ± 0.87 8.73 ± 0.94 4.00 ± 0.43 4.33 ± 0.47 4.60 ± 0.50 5.06 ± 0.55 6.07 ± 0.65
Table 2 Experimental cross-sections for the formation of 48V and 48Cr in the 165Ho(3He,x) reactions
EHe-3 (MeV) 26.94 ± 0.30 25.59 ± 0.34 24.17 ± 0.38 22.67 ± 0.43 20.94 ± 0.49 19.19 ± 0.56 17.19 ± 0.65 15.00 ± 0.77 35.80 ± 0.29 34.51 ± 0.32 33.20 ± 0.36 31.87 ± 0.40 30.60 ± 0.44 29.29 ± 0.48 27.85 ± 0.52 26.45 ± 0.57 39.12 ± 0.27 37.89 ± 0.30 36.80 ± 0.33 46.46 ± 0.27 44.89 ± 0.31 43.81 ± 0.33 42.76 ± 0.36 41.68 ± 0.39 40.58 ± 0.42
166
Tm 23.1 ± 2.9 24.7 ± 3.1 27.1 ± 3.3 28.6 ± 3.5 31.0 ± 3.8 31.1 ± 3.8 23.7 ± 2.9 8.1 ± 1.0 15.2 ± 1.9 14.8 ± 1.8 15.7 ± 2.0 18.6 ± 2.3 18.9 ± 2.4 19.6 ± 2.4 21.0 ± 2.6 22.6 ± 2.8 12.2 ± 1.5 13.3 ± 1.7 14.3 ± 1.9 8.6 ± 1.1 9.2 ± 1.2 9.7 ± 1.2 10.7 ± 1.3 11.2 ± 1.3 11.5 ± 1.3
σ (mb) 165 Tm 507 ± 58 577 ± 67 587 ± 68 504 ± 58 361 ± 42 205 ± 24 69.2 ± 8.0 7.69 ± 0.89 121 ± 14 139 ± 16 164 ± 19 208 ± 24 257 ± 30 318 ± 37 404 ± 47 489 ± 56 88 ± 10 99 ± 11 115 ± 13 51.2 ± 5.9 55.3 ± 6.4 59.3 ± 6.8 64.7 ± 7.5 69.5 ± 8.0 74.5 ± 8.6
163
Tm
184 ± 20 93 ± 10 38.3 ± 4.3 10.7 ± 1.3 1.67 ± 0.34
434 ± 48 319 ± 35 235 ± 26 897 ± 100 857 ± 95 819 ± 91 768 ± 86 698 ± 78 584 ± 66
Table 3 Experimental cross-sections for the formation of 166,165,163Tm in the 165Ho(3He,xn) reactions
500 natTi(3He,x)48V 450 This work Weinreich (1980) Tárkányi (1992) Ditrói (2000) Szelecsényi (2017) IAEA recommended
400
cross-section (mb)
350 300 250 200 150 100 50 0 0
10
20
30
40
50
60
70
EHe-3 (MeV)
Fig. 1 Re-measured excitation function of the monitoring reaction natTi(3He,x)48V – our cross-sections in comparison with the previously published results of Weinreich et al. (1980), Tárkányi et al. (1992), Ditrói et al. (2000) and Szelecsényi et al. (2017) and with the IAEA recommended data (Hermanne et al., 2018)
12 natTi(3He,x)48Cr
This work
10
Weinreich (1980)
cross-section (mb)
Ditrói (2000) Szelecsényi (2017)
8
6
4
2
0 0
10
20
30
40
50
60
70
EHe-3 (MeV)
Fig. 2 Excitation function of the natTi(3He,xn)48Cr reaction – our data in comparison with the previously published results of Weinreich et al. (1980), Ditrói et al. (2000) and Szelecsényi et al. (2017)
10
V-48 Cr-48
9
ejected activity (%)
8 7 6 5 4 3 2 1 0 0
10
20 3He
30
40
50
energy (MeV)
Fig. 3 Fraction of the 48V and 48Cr ejected from the monitoring stack as a function of energy
nat
Ti foil to the following foil in the
7
165Ho( 3He,2n)166Tm
35
6
This work
30
TENDL-2017
5
25 4 20 3 15 2
10 5
1
0
0 10
15
20
25 3He
30
35
40
45
predicted cross-section (mb)
experimental cross-section (mb)
40
50
energy (MeV)
Fig. 4 Cross-sections of the 165Ho(3He,2n)166Tm reaction – the measured values in comparison with the TALYS prediction adopted from the TENDL-2017 library
25
165Ho( 3He,3n) 165Tm
This work
600
TENDL-2017
20
500 15
400 300
10
200 5 100 0
predicted cross-section (mb)
experimental cross-section (mb)
700
0 10
15
20
25 3He
30
35
40
45
50
energy (MeV)
Fig. 5 Cross-sections of the 165Ho(3He,3n)165Tm reaction – the measured values in comparison with the TALYS prediction adopted from the TENDL-2017 library
25
165Ho(3He,5n)163Tm
800
20
600
15
400
10 This work
200
5
TENDL-2017
0
predicted cross-section (mb)
experimental cross-section (mb)
1000
0 30
32
34
36
38 3He
40
42
44
46
48
50
energy (MeV)
Fig. 6 Cross-sections of the 165Ho(3He,5n)163Tm reaction – the measured values in comparison with the TALYS prediction adopted from the TENDL-2017 library
8
165Ho( 3He,2n) 166Tm
production rate (MBq/µAh)
7 6 5 4 3 2 1 0 15
20
25
30 3He
35
40
energy (MeV)
Fig. 7 Thick target yield (production rate) for 166Tm in the 165Ho(3He,2n) reaction
45
production rate (MBq/µAh)
25
165Ho( 3He,3n) 165Tm
20
15
10
5
0 15
20
25
30 3He
35
40
energy (MeV)
Fig. 8 Thick target yield (production rate) for 165Tm in the 165Ho(3He,3n) reaction
45
50
production rate (MBq/µAh)
600
165Ho( 3He,5n) 163Tm
500
400
300
200
100
0 30
32
34
36
38 3He
40
42
44
46
energy (MeV)
Fig. 9 Thick target yield (production rate) for 163Tm in the 165Ho(3He,5n) reaction
48
50
Highlights The first measurement of the cross-sections for the (3He,xn) nuclear reactions on 165Ho. Benchmark for the prediction of 3He-induced nuclear reaction cross-sections in nuclear reaction model codes. New cross-sections for the monitoring reaction natTi(3He,x)48V are provided. New cross-sections for the potential monitoring reaction natTi(3He,x)48Cr were measured.
Declaration of interests ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. ☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:
Ondřej Lebeda Jan Ráliš Jan Štursa