Evaluation of the absolute emission probability of 1077 keV  -ray for 68 Ga

1. Evaluation of the absolute emission probability of 1077 keV -ray for 68Ga Huang Xiaolong 2013，6 China Nuclear Data Center China Institute of Atomic Energy, P.O. Box 275(41), Beijing 102413, China e-mail: huang@ciae.ac.cn

2. Status

3. Background +,1077keV =2.56%,China + 1077keV ,3~3.2%

4. Reason? a large difference between the cross section deduced with 511keV and 1077keV -ray is up to ~30% Maybe the current decay data of 68Ga, that’s the P (1077keV), has a problem.

5. Jiang’s Measurement Cross section exp.: Irradiation of the samples(Ga2O3 powder) was carried out at Cockcraft-Walton accelerator in CIAE and lasted 40 min. The finial results of 69Ga(n,2n)68Ga reaction c-s at En=14.9MeV was 103031(mb) with P (1077keV)= 2.560.09%.

6. Exp. data status on relative -ray intensities LRSW results are in good agreement with Jiang’s exp. and NDS eval. This means the present exp. data on relative -ray intensities are good.

7. Eval. P(1077keV)-1 The available measured I+ values are little changed: I+=8811%(1959Ra), 89.2%(1969Va16), 89.140.11% (1994Sc44 ) Assumed: I+= 89.140.11%. From LOGFT, /+(1077keV level) =1.505, /+(ground state)=0.1017, and -ray intensity balance, deduced P(1077keV)=2.810.01% This value is obviously different from the absolute measuremed value:3.220.03%, or Jiang’s deduced value: 2.560.09%.

8. Eval. P(1077keV)-2 In order to eval. the P(1077keV), the measured ratio of the intensity for positrons(pann) and intensity for 1077keV(p1077) are considered. The weighted average results are adopted as the measured values are discrepant.

9. Eval. P(1077keV)-3 Consider: Pann/P1077=65.60.4%. From LOGFT, /+(1077keV level) =1.505, /+(ground state)=0.1017, and -ray intensity balance, deduced P(1077keV)=2.720.16% I+=89.20.2% Also, this value is different from the absolute measuremed value:3.220.03%, or Jiang’s deduced value: 2.560.09%.

10. Discussion -1 In order to verify the rationality of our eval., mainly C-S measurements ~14.8MeV are adjusted using present eval. It’s obvious that the good agreement is obtained. Thus, present evaluated P(1077keV) is considered superior to other evaluations such as NDS/DDEP.

11. Discussion-2

12. 谢谢！