Recommended standards for gamma-ray energy calibration (1979)

ATOMIC

DATA

AND NUCLEAR

RECOMMENDED

DATA TABLES

STANDARDS

R. G. HELMER,*

24,39-48

(1979)

FOR GAMMA-RAY

P. H. M. VAN ASSCHE,?

Task group of the Commission of the International

ENERGY

CALIBRATION

(1979)

and C. VAN DER LEUNS

on Atomic Masses and Fundamental Union of Pure and Applied Physics

Constants

A consistent set of -y-ray energies, all with uncertainties of at most 10 ppm, is recommended for use in the energy calibration of y-ray spectra. Almost all y rays listed are from commercially available sources. The half-lives of the isotopes selected are generally at least 30 days. The y-ray energies, in the range E, = 60-6100 keV, are all based on the value of 411 804.4 t 1.1 eV for the y-ray from the decay of lgsAu. The energy of the 6129-keV line in 160, which is the y-ray with the highest energy of the present set, has also been measured relative to another standard; the two values are consistent.

* EG & G Idaho, Idaho Falls, Idaho, U.S.A.; work performed under the auspices of the U.S. Department of Energy t SCK-CEN, Nuclear Energy Centre, Mol, Belgium $ Fysisch Laboratorium, Rijksuniversiteit, Princetonplein 5, 3508 TA Utrecht, The Netherlands; Task group chairman 0092-640X/79/070039-10$02.00/0 Copyright 0 1979 by Academic Press, Inc. All rights of reproduction in any form reserved.

39

Atomw

Data

and

Nuclear

Data

Tables.

Voi

24,

NO

2, July

1979

HELMER,

VAN ASSCHE, and VAN DER LEUN

Calibration Gamma-Ray Energies

CONTENTS

INTRODUCTION

Gamma-Ray Energy Scales and Uncertainties Criteria for Selection. ..................................... ....................................... Recommendations ............................... Summary and Conclusions TABLE TABLE TABLE

I. I. II.

40

...........................................

Recommended Gamma-Ray Calibration ranged by Source ............................

..............

41 42 42 42

Energies Ar45

Appendix. Data for Values in Table I Which Are Based ................. on Two or More Experiments

47

Recommended rangedby

48

Gamma-Ray Calibration Energy ............................

Energies

Ar-

INTRODUCTION standards from his 1968 list of y-ray calibration energies, since a spread of 80 ppm occurred in the definitions of the x-ray wavelength unit. These errors in the primary standards are so large that they are ‘dominant in the final errors of almost all precision y-ray energies measured with present-day Ge(Li) detectors. When it became apparent that two completely different experiments were under way that would provide a definition of the y-ray energy scale that was about an order of magnitude better than that available at that time, the task group decided to wait with its recommendations forthe outcome of these experiments. The two experiments are:

During the 4th International Conference on Atomic Masses and Fundamental Constants, held in Teddington, U.K., in September 1971, it became clear that progress in precision y-ray spectroscopy, in particular the study of (n,y) and (p,y) reactions, was hampered by a lack of uniformity and precision in the y-ray energy standards used. In May 1972 the IUPAP Commission on Atomic Masses and Fundamental Constants established a task group, consisting of the authors of the present article. Its task is the production, recommendation, and publication of a consistent set of calibration standards for use in y-ray spectroscopy. At that time, the y-ray energies available for precision calibration were based essentially on two primary standards:

(a) The double-flat-crystal spectrometer measurements at the U.S. National Bureau of Standards, aiming at a precision of < 1 ppm for the absolute wavelength of the 41ZkeV lgsAu line. (b) The high-precision determination with Lincoln Smith’s mass spectrometer of isotopic mass differences of a series of light nuclei, which provides an energy scale especially relevant for y-rays with energies of E, > 5 MeV.

(a) the value of 411 794 ? 7 eV for the ls*Au y-ray (or more basically the energy equivalent of the electron mass), and (b) the energies of atomic x-rays, in particular the W Kal line with an energy of 59 320.15 ? 0.36 eV. The standard, than the however,

quoted error in the energy of the tungsten 6 parts per million, is appreciably smaller 17-ppm error in the gold standard. Marion,’ eliminated all data related to the x-ray energy

The results of these measurements were published by Kessler et a1.2 in 1978 and by Smith and Wapstra3,4 in 1975, respectively.

40

Atomic

Data and Nuclear

Data Tables,

Vol. 24. No. 2, July

1979

HELMER.

VAN ASSCHE, and VAN DER LEUN

length conversion factor.“7 The general question of the effect of recent experimental results (in particular that of the results of Deslattes et al.‘” on the Avogadro constant) on the fundamental constants is discussed by Cohen.” However, until a complete readjustment of the fundamental constants is available, the task group decided to use the value quoted above. For high-energy y-rays a second independent scale is important. It can be based on mass spectrometric measurements of isotopic mass differences.“.’ These mass differences have been related to energies of neutron-capture y rays via the calculation of neutron binding energies. This calculation is not satisfactory at present, however, since it involves the deuteron binding energy, recent measurementP2” of which show a discrepancy of about SO eV. In view of this problem it was decided to restrict the presently recommended calibration energies to values based on the wavelength scale. The highest y-ray energy based on this scale, the E, = 6 129 270 it 50 eV line in “0, was measured by Shera’” on the mass-doublet scale as E, = 6 129 170 + 43 eV. This means that the y-ray energies based on the Shera value are essentially consistent with energies based on the present set of calibration energies. In view of the uncertainties in both scales (the waveIengthenergy conversion factor and the deuteron binding energy, respectively), however, this does not yet imply that the two scales are consistent. It might be noted that, as in the case of the lVHAu scale, the final error in the mass-doublet scale is also dominated by another error source. in this case the deuteron binding energy. A third possibility is a scale based on the 511-keV radiation following positron-electron annihilation. A comparison of this 5 1 1-keV radiation to more useful standards such as the 412-keV lgHAu line, although it confirms the upward energy shift found in Ref. 2, has been made with a precision of only 12 ppm.?” The 51 I-keV annihilation line is not included in the present list of recommended energies since Doppler broadening causes the line shape to be much wider than that of y rays. Moreover, the average photon energy depends on the electron binding energy in the annihilating material. Similar arguments exist against a fourth possibility, the use of x-rays for calibration purposes. The inconsistency of the relative x-ray wavelengths has already been mentioned. Also. the finite line width of the x-rays, generally larger than the energy resolution of diffraction spectrometers, complicates their use for good-quality (< 10 ppm) calibration. Finally, both the line shape and the observed energy can be influenced by the excitation process used to generate the x-rays.2fi

For the present recommendation, which concentrates on low-energy y rays, the 1978 publication is the crucial one. In the following sections, this paper discusses -the definition of the energy scale, -the criteria for selection of isotopes and data, -the recommended calibration standards, and -some conclusions. A preliminary account of this work has been given in Ref. 30. Gamma-Ray Energy Scales and Uncertainties

Definition

Calibration Gamma-Ray Energies

oj. Scales

The recent article of Kessler et al.’ reports a series of measurements for determining a very precise absolute wavelength for the 412-keV y-ray from the decay of ISRAu, as well as for other y-rays. The experiment essentially relates the y-ray wavelength to optical wavelength standards. First, the wavelength of the photons from a 12sI,(B)-stabilized HeNe laser is linked to the Cs oscillator frequency, yielding an uncertainty in the optical wavelength of 0.004 ppm. The nuclear wavelength measurements require synthetic Ge and Si single crystals with high geometric perfection. The lattice spacings of these crystals are compared to the standard optical wavelengths by x-ray interferometry, a technique developed by Bonse and Hart.5 The absolute y-ray wavelengths are then determined by y-ray diffraction at these crystals in a double-flatcrystal spectrometer. A review of all the steps that cover 10 decades in the electromagnetic scale is given in Ref. 23. The resulting wavelength for the 412-keV line of lyHAu is 3 010.778 8 + 0.001 1 fm. The corresponding y-ray energy is 411 804.4 2 1.1 eV, based on the voltage-wavelength conversion factor of (1 239 852.0 ? 3.2) x lo3 eV fm from Cohen and Taylor.’ In the final uncertainty the error in the conversion factor (2.6 ppm) dominates that in the wavelength measurement (0.37 ppm). In the present evaluation all of the energies are on the energy scale based on this value. To some degree this is an arbitrary choice of a reference energy, since Kessler et a1.2 have also reported energy values for several lg21r lines which could equally well be used as the basis of the energy scale. The choice is based on the fact that more extensive measurements were made for lysAu than for rg21r, together with the fact that it has been the custom in recent years to use the 4lZkeV line from lgBAu as an energy reference. One disconcerting fact is that it must be expected that the next adjustment of the fundamental constants will result in a significant change in the voltage-wave-

41

Atomic

Data and Nuclear

Data Tables.

Vol. 24, No. 2. July 1979

HELMER, VAN ASSCHE, and VAN DER LEUN

Calibration Gamma-Ray Energies

Uncertainties

Data Selection

In this paper the final uncertainty in the 412-keV lseAu line of 2.6 ppm will be taken as the uncertainty in this reference scale, AE, (ref.). For all the energies quoted in the tables, a distinction is made between two components of the uncertainty: (1) the contribution from the reference energy defining the energy scale, AE, (ref.); and (2) the contribution from all subsequent measurements, AE, (meas.). These components are combined quadratically to obtain a total or absolute error, AE, (tot.) or simply AE,. The quoted errors are intended to be estimates of the standard deviations (that is 68% confidence level values).

A few quite simple data selection been used. The data must be:

Relationships

For Ge spectrometer

data additional

criteria are:

-at

least two different spectrometers have been used in the measurements -only similar pees are compared in the bootstrapping procedure (calibration of doubleor single-escape peaks on full-energy peaks is an unacceptable source of potential and often irreproducible errors) -timeand direction-dependent effects are avoided through simultaneous and unidirectional measurements

As noted above, all of the ‘y-ray energies listed in the tables are based on the ls8Au y-ray energy of 411 804.4 & 1.1 eV. The group of -y-ray energies which are most closely related to this value are either those from other absolute wavelength measurements2*25 or those from curved-crystal diffraction spectrometer measurements made relative to the lg8Au line. The y rays of these isotopes (that is 51Cr, 57Co, ‘j°Co, 13’Cs, 152Eu, 153Gd, “OTrn, lE2Ta, lg21r, lg8Au, and 203Hg) are thus tied directly to the lssAu line. The remaining values quoted herein have all been determined by measurements of small y-ray energy differences made with Ge semiconductor detectors. For these measurements, the cascade-crossover relationships have been essential to the extension to higher energies. The details of the methods used are given in Refs. 6 and 8. The cascade-crossover relations used to calibrate the 6.13-MeV line in 160 were generated by the use of resonances in the 25Mg(p,Y)26A1 reaction. l2

Selection

have

-published or submitted for publication -measured on the first energjl scale defined above, or trivially convertible to that scale (this excludes data for which reference and measurement errors are not given separately) -sufficiently documented to enable the reader to judge the quality -of good quality and precision (uncertainties do not exceed 10 ppm)

within the Energies

Criteria of Sources

criteria

Recommendations The recommended y-ray energies, with errors and references to the original literature, arranged by source, are given in Table I. In case two or more values from the literature have been used, these values and the weighted average (as listed in Table I) are given in an Appendix to Table I. In several cases, the values listed differ from the values given in the original literature because of the conversion to the energy scale based on a 19*Au energy of E, = 411 804.4 -C 1.1 eV. These values are all marked as such. For convenience a summary of the recommended values arranged by y-ray energy is presented in Table II.

for Selection

The list of recommended y-ray calibration energies does not include all of the precise y-ray energies that are known. Selected are those deemed most useful in the general situation. Preference is given to lines from long-lived sources (that is with half-lives of at least 30 d) that are commercially available. A few short-lived isotopes (for example 24Na with a 15-h halflife) are included since they can be produced easily. A few others are listed primarily to provide a y-ray in an energy range in which no line from a long-lived source is available. Since the main aim is to provide calibration lines for Ge(Li) and Ge y-ray spectrometers, sources with spectra too complex for this purpose are not listed.

Summary

and Conclusions

The present list of y-ray energy calibration standards is the first list recommended by the IUPAP task group. The energies fall in the range E, = 60-6100 keV. As expected, the coverage decreases with E,. This is illustrated in Fig. la, where the number of lines per 200-keV interval (see Table II) is plotted. Accordingly, the gaps between two adjacent lines increase with Ey; this is illustrated in the plots of the largest gap per lOO-keV interval (drawn histogram) and per 500-keV interval (dotted histogram); see Fig. lb. On the average, the relative uncertainties in the values listed increase with E,. This increase, however, does not proceed

42

Atomic

Data and Nuclear

Data Tables,

Vol. 24. No. 2, July

1979

HELMER,

1979

> e 0

20-

GAMMA-

RAY

VAN ASSCHE, and VAN DER LEUN

CALIBRATION

a)

Calibration

1979

STANDARDS

Gamma-Ray Energies

GAMMA-RAY

CALIBRATION

STANDARDS

UNCERTAINTIES

COVERAGE

F? B z

610-

t

b) GAPS P

2 w

c

400-

I

I

I

10

20

3.0

--w

MO-

4I 200

I

Ey(MeV)

Fig. 2. Uncertainties of the most accurately known calibration line per l(H)-keV interval. The lower dashed line represents the 2.6-ppm error due to the reference scale. 1

2.0 -

I

c

Afuture aim of the task group will be the extension of the present evaluation to higher energies as more precise measurements become available. Reaction y-rays will inevitably dominate this region, The task group welcomes (at its Utrecht address; see above) information on experiments and publications providing precision values for

3.0 Ey(MeV)

Fig. 1. (a) Histogram of the number N of calibration lines per 200-keV interval, (b) Histograms of the largest gap between two adjacent calibration lines per lOO-keV interval (solid line) and per SOO-keV interval (dashed line).

-high-energy y-rays (E, > 3 MeV) that are candidates for the extension of the present list -medium.-energy y-rays (E, = 1.5-3.0 MeV) for filling the gaps in the present list -low-energy y-rays (E, < 1.5 MeV) for improving and updating the present list

gradually, as is clear from Fig. 2, where the total uncertainty of the best-known line in each !OO-keV interval is plotted against E,. For E, > 1.7 MeV, and in particular for E, = 1.7-2.0 MeV, the smallest measurement errors are still considerably larger than the systematic error of 2.6ppm from the reference scale. A frequently used previous recommendation of y-ray calibration energies is that of Marion,’ dating from 1968. A comparison of the 1968 values with the presently recommended values indicates that the present uncertainties are about one order of magnitude smaller than the earlier ones. It must be expected that the values for the recommended energies will change with time, mainly because of readjustments of the fundamental constants. Therefore, it is desirable that new information based on y-ray energies (including quantities such as Q-values) be published in a form that allows conversion to any new y-ray energy scale. Alternatively, the experimenter should maintain the basic experimental results, so that he can recompute the final values when a new y-ray energy scale becomes available.

Equally welcome are comments about possible errors, omissions, or the selection procedure that might lead to improvements in future evaluations. Acknowledgments The task group acknowledges the stimulating support received from the IUPAP Commission on Atomic Masses and Fundamental Constants, in particular from Drs. E. R. Cohen, W. H. Johnson, and A. H. Wapstra, and from the Editor of Atomic Data and Nuclear Data Tables, Dr. Katharine Way. References 1. J. B. Marion, (1968)

NUCLEAR

DATA

TABLES

A4, 301

2. E. G. Kessler, R. D. Deslattes. A. Henins, and W. C. Sauder, Phys. Rev. Lett. 40, 171 (1978)

43

Atomic

Data and Nuclear

Data Tables.

Vol

24. No

2. July

1979

HELMER,

VAN ASSCHE, and VAN DER LEUN

18, 0. Piller,

4. A. H. Wapstra, in Proc. 2nd Znt. Conf. on Neutron Capture Gamma-Ray Spectroscopy (R.C.N., 5. U. Bonse and M. Hart, (1965)

19. G. L. Borchert,

W. Scheck, and 0. W. B. Schult, Nucl. Instr. 124, 107 (1975)

Appl. Phys. Lett. 6, 155

R. C. Greenwood, Nucl. Instr. 155, 189 (1978)

W. Beer, and J. Kern, Nucl. Instr. 107,

61 (1973)

1975), p. 686

6. R. G. Helmer,

Gamma-Ray Energies

17. W. Beer and J. Kern, Nucl. Instr. 117, 183 (1974)

3. L. G. Smith and A. H. Wapstra, Phys. Rev. C 11, 1392 (1975)

Petten, The Netherlands,

Calibration

20. P. H. M. Van Assche, H. Borner, W. F. Davidson, and H. R. Koch, in Atomic Masses and Fundamental Constants 5, edited by J. H. Sanders and

and R. J. Gehrke,

A. H. Wapstra (Plenum,

J. Phys. Chem. Ref. Data 2, 663 (1973); E. R. Cohen, ATOMIC DATA AND NUCLEARDATA TABLES 18,587(1976)

New York, 1976), p. 37

7. E. R. Cohen and B. N. Taylor,

8. R. C. Greenwood,

R. G. Helmer, Nucl. Instr. 159, 465 (1979)

21. R. G. Helmer,

Nucl. Instr. 164, 355 (1979)

22. R. D. Deslattes (1974)

and R. J. Gehrke,

et al., Phys. Rev. Lett. 33, 463

23. R. D. Deslattes,

in Proc. Course LXVZZZ “Metrology and Fundamental Constants” (Summer School of Physics-Enrico Fermi, Varenna, Italy, 1976)

9. E. R. Cohen, in Proc. Course LXVZZZ “Metrology

and Fundamental Physics-Enrico 10. G. L. Borchert,

Z. Naturforsch. 11. G. L. Borchert,

Constants” (Summer School of Fermi, Varenna, Italy, 1976) W. Scheck and K. P. Wieder, A 30, 274 (1975) Z. Naturforsch.

24. R. G. Helmer,

R. J. Gehrke, and R. C. Greenwood, Nucl. Instr. 166, 547 (1979)

A 31, 387 (1976)

25. E. G. Kessler,

Deslattes,

12. P. F. A. Alkemade, C. Alderliesten, P. de Wit, and C. van der Leun, Nucl. Instr., in press

L. Jacobs, W. Schwitz, and R. D. Nucl. Instr. 160, 435 (1979)

26. G. L. Borchert

et al., Phys. Lett. A 66, 374 (1978)

13. G. L. Borchert, W. Scheck, and 0. W. B. Schult, in Atomic Masses and Fundamental Constants 5, edited by J. H. Sanders and A. H. Wapstra (Plenum, New York, 1976), p. 42

27. E. R. Cohen, Sixth Int. Conf. on Atomic

14. J. Kern and W. Schwitz,

29. R. C. Greenwood C 21,498 (1980)

Nucl.

Instr.

East Lansing, 28. T. Vylov

et al., Yadernaya transl., p. 585

151, 549

(1978)

15. J. J. Reidy, in The Electromagnetic Interaction in Nuclear Spectroscopy, edited by W. D. Hamilton (North-Holland, Amsterdam, 1975), p. 873

Masses,

Mich. (1979) Fiz. 28, 1137 (1978);

and R. E. Chrien, Phys. Rev.

30. C. van der Leun, R. G. Helmer, and P. H. M. Van Assche, in Atomic Masses and Fundamental Constants 6, edited by W. Benenson and J. A.

Nolen (Plenum,

16. E. B. Shera, Phys. Rev. C 12, 1003 (1975)

44

Atomic

New York, 1980), p. 499

Data and Nuclear

Data Tables.

Vol. 24, No. 2. July

1979

HELMER.

TABLE

Source

VAN ASSCHE,

I. Recommended

Half-life

El(e")

13c

Z2Na

+ a

53

2.6

Calibration

was.

3

6

6 129 270

50

50

12

y

1 274 542

6

7

6

952,

64 d

724 199

5

g4Nb

20 by

702 645 871 119

3

10Efigm Z4Na

15

h

1 368 633 2 754 030

4 12

6 14

a

4%

a4

d

889 277 1 120 545

2 3

3 4

6

5'C,

28

d

320 084.2

0.4

0.9

54Mn

313

d

a34 a43

5

6

a

59Fe

45

d

1 099 251 1 291 596

3 6

4 7

6

%O

79

d

5 3 8 5 5 14 17 11 10 10 11 8 7 15 12 11 11 10

6 4 8 6 6 15 17 12 11 11 12 10 10 17 14 14 14 13

6 8

%

271

d

y

a46 037 175 238 360 771 810 963 015 034 113 212 598 009 201 253 272 451

764 044 099 287 206 350 722 714 179 759 107 921 460 596 954 417 998 154

122 061.35 136 474.3

Energies Arranged by Source

total

3

1 1 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3

0.12 0.3

0.3 0.5

1 173 238 1 332 502

3 3

4 5

l10A9m

127 y

252

d

10 b)

I I 1 1 lz45b

lp4Sb

60 d

60

433 936 614 281 722 929

4 4

446 620 657 677 687 706 744 763 818 884 931 384 475 505 562

3 3 1.3 1.6 3 2 3 2 4 2 3 3 4 3 3

6

6 4 4 4 4

4

811 360 762.2 622.7 015 682 277 944 031 685 493 300 788 040 302

6

24

3 3 2 2 3 3 3 ? 4 3 4 4 6 5

3 2 5

a’

a

7 5

786 712 201 131 512 164 563 980 942

4 6 4 3 5 6 6 4 7

6 a

661 660

3

3

,

696 510 1 489 160 2 185 662

3 3 4

3 5

4

0.3 0.8 1.7

0.4

d

722 790 968 045 325 368 436 690 090

tot.31

5

602 730 645 855 713 781

I 1 1 1 1 2

4 7

H

4 4 6 7

11 b, 30 Y 284

6OCO

5.3

%n

244 d

1 115 546

2

4

6

%

107

898 042 1 a36 063

3 12

4 13

6 a

d

13 Y d

Gamma-Ray Energies

Ref.

477 605

d

a-source

Gamma-Ray

AEp") meas.

‘ae

Calibration

and VAN DER LEUN

45

121 782.4 244 698.9 344 281.1

Atomc

Data

and

Nuclear

11 b)

1.0

1.9

Data

Tables.

Vol

24.

NO.

2,July

1979

HELMER,

TABLE

smwce

VAN ASSCHE, and VAN DER LEUN

I. Recommended

Half-1lfC

Gamma-Ray

meas.

total

15&

242 d

+9 673.4 97 431.6 103 180.7

0.1 0.2 0.2

0.2 0.3 0.3

170Tn

129 d

84 255.10

0.19

0.3

lB21a

115 d

0.14 0.3 0.18 0.2 0.6 0.3 0.3 0.3 0.3 0.3 0.6 0.3 4 4 4 4 4 4 4 4 4

0.2 0.3 0.3 0.4 0.7 0.5 0.5 0.5 0.6 0.6 0.9 0.8 5 5 5 5 5 5 5 5 5

1 1 1 1 1 1 1 1 1

a) See table

I - Appendix.

67 84 1w 113 116 152 156 179 198 222 229 264 121 189 221 231 257 273 289 373 307

150.01 680.8 106.53 672.3 418.6 430.8 387.4 394.8 353.0 109.9 322.0 075.5 301 050 400 016 418 730 156 836 402

b) Values

Calibration

smrce

Ref.

bE+eV)

Ep)

a$ corrected

Calibration Gamma-Ray Energies

lg21P

11 bJ

Energies Arranged by Source

Half-life

74 d

EJeV)

136 205 295 308 316 416 468 4a4 588 604 612 884

343.4 795.50 958.21 456.05 508.00 471.9 071.5 577.9 585.1 414.55 465.69 542.3

Ref.

qev near.

tots1

0.3 0.07 0.12 0.14 0.15 0.6 0.2 0.4 0.6 0.17 0.19 0.5

0.5 0.5 0.8 0.8 0.8 1.2 1.2 1.3 1.6 1.6 1.6 2

a)

2.7 d

411 004.4 675 887.5 1 087 690.5

0.2 0.7 0.7

1.1 1.9 3

2 01

M

47 d

279 196.7

0.9

1.2

a)

207Eli

36 Y

203 6

'%h

In ref.

1.9 y

569 702 1 Ci63 662 1 770 237 236 583 860 893 1 620 2 614

2 3 9

2 4 IO

6

632 191 564 406 735 533

2 2 4 4 9 11

2 2 5 5 10 13

21 6 21

Data and

Nuclear

Data Tables.

8

8

6.

46

Atomic

Vol. 24, No.P.July

1979

HELMER,

IJABLE

I-APPENDIX.

source

Data for Values in Table I Which Are Based on Two or More Experiment&

Source

Reference

Ey + AE+eas.)

El

240

+

6

11

1 173

237

t

3

6

a'

Frm ces

238

t

1 332

504

+

1 332

501

24

1 332

502

+

l10A9m

446 810

average

7

11

3

average

8

5 5

13

(eV)

1 384 335

2 80

13

136 343.8

+ 0.7

10

1 384 310

+ 30

14

136 343.3

+ 0.7

I7

+ 0.3 + 0.6

1 384 300

t

3

aI

136 343.4

1475

+

4

aI

205

788

1 505 089

+ 90

1 505 040

c3

1 562 302

f.

13 al aI

3

Cl 10

205

795.49

+ 0.07

2

205

795.50

A 0.07

c) 10

295

958.5

+ 0.5

295

958.25

+ 0.13

2

958.21

+ 0.12

Cl

+ 2

84

253.8

+

0.4

17

295

818

+

5

14

805

t

6

8

84

254.78

+

0.13

10

308

455

3

aI

84

255.23

+

0.07

25

308

456.89 + 0.15

7

84

255.10

5

0.19

average

306

456.85

+ 0.14

C)

316

508.5

$0.3

67

751.3

5

0.6

18

316

507.89

+ 0.18

67

749.97

+

0.13

19

316

508.00

+ 0.15

67

750.01

+

0.14

bl

446

811

+

620

366

+ 17

13 14

17OT.

620

363

16

620

362

+

6

620

360

+

3

657

760

f.

4

13 14

84

682.9

+

1.0

8

84

680.8

+

0.3

aI

100

109.2

+

0.9

8

182Ta

aI

657

762

$2

657

764

+

3 1.3

18 b)

10

10

416 471

L 3

2 cl 10

416 471.9

+ 0.6

468

072.0

+ 0.6

Cl 10

657

762.2

i

18

468

071.5

+ 0.3

2

677

611

+ 14

13

100 106.52 + 0.06

19

468

071.5

t

ci

677

621

+

7

14

100 106.53 + 0.18

IvePage

484

576.9

t 1.8

677

618

+

4

8

113 670.2

1.5

18

484

578.0

t

677

622.7

2

1.6

a)

113 672 5 + 0.3

19

484

577.9

+ 0.4

687

007

t

14

13

113 672.3

?. 0.2

bl

587

008

+

9

8

116 418.1

5 1.9

687

015

+

3

a1

116 418.6

+ 0.6

706

681

:

5

13

152 432.4

+ 1.9

ia

706

681

t

5

14

152 430.6

+ 0.3

19

706

682

+

5

8

152 430.8

t

0.3

bl

706

682

+

2

a)

156 386.1

+

1.7

18

+

588588

18 bl

0.2

10

0.4

2 cl

t4

10

588

584.5

+ 0.T

588

585.1

+ 0.5

604

413

f 2

7 cl 10

604

414.2

+ 0.5

604

414.55

+ 0.17

612 467

2 cl

+ 3

10

744

264

+ 20

13

156 387.6

2

0.4

19

612

465.0

z 0.8

2

744

267

+

8

8

156 387.4

+

0.3

bl

612

465.69

+ 0.19

Cl

744

277

+

3

aI

179 395

f

2

18

884

542.3

5 0.5

Cl

763

955

+

4

13

179 395.0

+

0.5

19

763

934

+

7

14

179 394.8

+

0.3

bl

675

887.4

t

763

941

+

6

8

198 353

+

3

18

675

890

+ 4

11

763

944

f

2

aI

19

average

198

352.7

2

0.4

818 046

+ 15

13

198

353.0

+

0.3

818 033

+ 12

8

222

106.9

*

3

18

818 031

+

aI

222

109.5

t

Cl.4

19

884687

517

222

109.9

+

0.3

4

13

2 2

685

+

884

685

+

937

489

+ 19

bl

+ 0.9

bverage

229

322

aI

229

322.0

t

0.6

19

13

229

322.0

+

0.6

average

14

264

078

?.

6

18

6

8

264

075.7

+

0.6

19

937

493

+

3

aI

264

075.5

+

0.3

bl

fit

in

ref.

a

Ieast-squares

fit

reported

Fran

a least-Squares

fit

In

ref.

corrected

in

which

the

energies

listed

here

are

used

IS

Input

together

with

sm

precistao

10

energy-dtfferen-

8.

fm

in

8,

196

279 196.7

+

ref.

279

6

18

+ 13

in

2 0.7 + 0.7

15

496

a least-squares

887.5 690.5

23 z 1.0

937 490

reported

675 087

2

279 196.8

8

+4

0.7

bl

937

as

796.1

446

"

Values

Reference

+ dEl(me.=.)

446

b)

dl

l10A3Ml

3

884

reported

El

(eV1

1 173

1 173

source

Reference

+ ~E$neas.)

(W

6OCO

Calibration Gamma-Ray Energies

VAN ASSCHE, and VAN DER LEUN

in

ref.

6.

ref. in

6, which

In

which

the

listed

new

value

the

data data

fra of

refs. refr2

and

18 and 19, llsted 10 are used as

here. input

are used as Inpt. together

with

tme

energy

differences

6. In

refs.

6 and

8 for

the

of

the

412

47

keV

lg8A,

line.

Atomc

Data

and

Nuclear

Data

Tables,

Vol.

24.

No.

2,JulV

,979

HELMER,

TABLE

VAN ASSCHE, and VAN DER LEUN

II. Recommended

Gamma-Ray

Calibration

Calibration

Gamma-Ray Energies

Energies Arranged by Energy”

source

182T.3

67

750.0

+ 0.2

lmA9'

1536d

69

673.4

+ 0.2

l10A9m

1'OT.

84

256.1

+ 0.3

'**la

84

680.8

153Gd

97

431.6

EyW

614

281

+4

1 231

016 2

5

620

360

+3

1 238 237 +

6

124Sb

645

855

+ 2

1 257 418 +

5

+ 0.3

l10A9m

657

762

+ 2

1 273 730 +

6

+ 0.3

13’cs

661 660

+ 3

1 274 542 +

7

lg8A"

675

887.5

+ 1.9

1 289 156 +

5

'%a

100 106.5 + 0.3

153M

103 180.7 + 0.3

l10A9m

677

623

+ 2

1 291 596 5

7

‘8’T,

113 672.3 + 0.4

l10A9m

687

015

t

1 325 512 +

6

102Ta

116 418.6 + 0.7

‘44ce

696

510

+ 3

1 332

+

5

l52EU

121 782.4 + 0.4

702

645

+6

1 360 206 5

6

5'co

122 061.4 + 0.3

g41b llOAOm

706

682

L 3

1 368

7

1921,

136 343.4 + 0.5

lz4Sb

713

781

$5

1 368 633 + 6

5’0

136

474.3

+ 0.5

lz4Sb

722

786

t4

I 373

lE21a

152

430.8

+

l"Agm

722

929

+ 4

1 384 300 + 4

182T,

156

387.4

+ 0.5

124 199

+ 5

1 387 402 2 5

182TZZ

179 394.8 + 0.5

llOAgm 744

277

+3

1 436 563 2

182T,

198 353.0 + 0.6

llOAgm

763

944

+ 3

1 475 788 + 6

19%

205

795.5

lz4Sb

790

712

+

182T,

222

109.9 + 0.6

l8*Ta

229

322.0

+ 0.9

'**Th

238

632

+ 2

152E"

244

698.9 + 1.0

182T,

264

075.5

203H9

279 196.7 + 1.2

lg21,

295

0.5

g5Zr

+ 0.5

t

164

836

+

+

5

7

1 489 160 +

5

+4

1 505 040 +

6

54M"

834

043

+ 6

1 562 302 +

5

55C0

846

764

26

1 620 735 c 10

7

860

564

+ 6

1 690 980 +

871

119

f. 4

1 770

237

+ 10

‘9% IIOA9m

084

542

+2

1 771

350

+15

884

685

f. 3

1 810 722 + 17

46%

228Th 34Nb

0.8

502

818 031

llOAgm

+ 0.8

958.2

3

6

19%

305

456.9

+ 0.8

889

277

$3

1 836 063 + 13

lg21,

316

508.0

+

0.8

228Th

893

408

f. 5

1 963 714 + 12

5lC,

320

084.2

+ 0.9

@Y

898

042

54

2 015

179

152Eu

344

281.1

+ 1.9

llOAgm

937

493

+4

2 034

759 2 11

lg8A"

411 804.4 + 1.1

968

201

1921,

416 471.9 + 1.2

12'Sb 56C0

+11

+ 4

2 090

942

+

1 037 844

+ 4

2 113

107

+ 12

8

+

ImAp

433

936

+ 4

124Sb

1 045

54

2 185

662

l10A9m

446

811

+ 3

207ai

1 063 662

+ 4

2 212

921 + 10

lg21r

131

7

468

071.5

+ 1.2

l%AU

1 087 691

+ 3

2 598

460

‘Be

477

605

+ 3

5gFe

1 099 251

+ 4

2 614

533

5 13

1921r

484

577.9

2

65zn

1 115 546

f 4

2 754

030

+ 14

45sc

1 120 545

t. 4

3 009

596

+ 17

182Ta

1 121 301

+5

3 201

954

+ 14

1.3

+10

207ai

569

702

+ 2

228Th

583

191

22

1321,

588

585.1

+ 1.6

6oCO

1 173 238

+4

3 253

417

tl4

lz4Sb

602

730

+

5%

1 175 099

t 8

3 272

998

f

14

1921,

604

414.6

+ 1.6

1827,

1 189 050

+ 5

3 451

154

+

13

1921,

612 465.7 + 1.6

l*2T=

I 221 408

+ 5

5 129

270

+ 60

a)

For

reference5

and

3

details.

see

table

I

48

Atomic

Data and Nuclear

Data Tables,

Vol. 24, No. 2. July 1979