Accelerator mass spectrometry(AMS) is an ultrasensitive technique for measuring long-lived actinides,e.g.,^(236)U,^(237)Np and Pu isotopes.In order to improve the detection limit for actinides abundance,and to increase the detection efficiency in actinides AMS measurement,a 16-strip silicon detector was used to identify actinides at the Center for Isotopic Research on Cultural and Environmental heritage in Caserta,Italy.The sensitivity of ^(236)U/^(238)U was 1×10^(-11) by special resolution and 5.0×10^(-12) by time resolution.The pulse height defect of^(236)U in an ion-implanted silicon detector in the low-energy range with 17.26 MeV is presented.
Yong-Jing GuanHui-Juan WangMario De CesareFilippo Terrasi
36Cl is one of the most interesting nuclides in accelerator mass spectrometry (AMS) measurements. The application of 36Cl has been widely applied in various fields. All most all of 36Cl AMS measurements at natural isotopic concentrations have yet been performed at tandem accelerator with 5 MV or higher terminal voltage. The measure improvement of 36Cl and other medium heavy isotopes performed at 3 MV in AMS facilities is one of the hottest topics in AMS measurements. In order to increase the suppression factor of 36S, the energy loss straggling and angular straggling of 36Cl and 36S ions in various counter gases (P10, isobutane and propane) were investigated. Some groundwater samples were measured with energy of 32 MeV, and the results were in good agreement with the result obtained with ion energy of 72 MeV. The results indicate that the approximate detection limit of 36Cl in 3 MV AMS facility is 36Cl/Cl=1×10-14 , and the uncertainty is 30% when the sample with isotopic ration 36Cl/Cl≈10-13.
WANG HuijuanGUAN YongjingZHANG WeiJIANG ShanMing He
