Evaluation of the absolute emission probability of 1077 keV -ray for 68 Ga Huang Xiaolong 2013 , 6 China Nuclear Data Center China Institute of Atomic Energy, P.O. Box 275(41), Beijing , China
2 Status P (511)P (1077) Comments 1994Sc Absolute Exp. 2012Lu Absolute Exp. Jiang(2011) deduced Table of Isotope, 7th edition Eval. NDS Eval. DDEP Eval.
3 Background ++ 1077keV,3~3.2% +, 1077keV =2.56%,China
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 68 Ga, that’s the P (1077keV), has a problem.
5 Jiang’s Measurement Cross section exp.: Irradiation of the samples(Ga 2 O 3 powder ) was carried out at Cockcraft-Walton accelerator in CIAE and lasted 40 min. The finial results of 69 Ga(n,2n) 68 Ga 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), 0.11% (1994Sc44 ) Assumed: I + = 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(p ann ) and intensity for 1077keV(p 1077 ) are considered. The weighted average results are adopted as the measured values are discrepant.
9 Eval. P (1077keV)-3 Consider: P ann /P 1077 =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!