鉴于国内核物理实验对高性能硅探测器有大量需求,而国外对中国进行技术封锁,满足实验需求的高性能探测器不易获得.中国科学院近代物理研究所在原有制备工艺基础上首次采用套刻技术,有效减少了光刻及腐蚀过程造成的Si O2沾污,大幅提高了...鉴于国内核物理实验对高性能硅探测器有大量需求,而国外对中国进行技术封锁,满足实验需求的高性能探测器不易获得.中国科学院近代物理研究所在原有制备工艺基础上首次采用套刻技术,有效减少了光刻及腐蚀过程造成的Si O2沾污,大幅提高了探测器性能和成品率.本文对采用该工艺研制的300μm厚,有效面积50 mm×50 mm硅探测器进行电学性能测试和在束探测性能测试.探测器在-45 V耗尽电压下,其漏电流小于40 n A,对5 Me V左右的a粒子的能量分辨(σ)约为45 ke V.将该探测器作为能量沉积(ΔE)探测器,利用250 Me V/u的11C放射性束流及其在次级碳靶上的反应产物对探测器进行了探测性能测试.测试结果显示,该探测器对于C元素的电荷数Z的分辨为0.17,与文献中记录的国外生产的同类型探测器的实验数据(Z分辨0.19)相当,可以满足中高能放射性束实验对轻质量区粒子鉴别的要求.展开更多
The (EC+β^(+)) decay of ^(128)Ce was reinvestigated in the^(116)Sn (l6O, 4n) reaction by using a helium-jet tape transport system. The decay γ rays of ^(128)Ce were unambiguously described from those of ^(129)Ce aft...The (EC+β^(+)) decay of ^(128)Ce was reinvestigated in the^(116)Sn (l6O, 4n) reaction by using a helium-jet tape transport system. The decay γ rays of ^(128)Ce were unambiguously described from those of ^(129)Ce after taking the comparing experiments of ^(16)O+^(116)Sn and ^(16)O+^(117)Sn. Based on x-γ and γ-γ coincidence measurements, a detailed (EC+β^(+)) decay scheme of ^(128)Ce has been proposed which modifies the previous one, and takes accounts of 100 observed γ-lines.展开更多
The nuclide ^(129)Ce was produced by a(^(16)O,4n)reaction on an enriched ^(117)Sn target.Reaction products were transported to a shielded location by using a helium-jet tape transport system.An activity of 4.1 min in ...The nuclide ^(129)Ce was produced by a(^(16)O,4n)reaction on an enriched ^(117)Sn target.Reaction products were transported to a shielded location by using a helium-jet tape transport system.An activity of 4.1 min in chemically separated cerium sample was identified as ^(129)Ce.Based on x-γ-t andγ-γ-t coincidence measurements,the(EC+β+)decay scheme of ^(129)Ce was proposed,and takes accounts of 50 observedγ-lines.展开更多
The β-delayed proton decay of 147Er is studied experimentally using the 58 Ni+92Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the β-delayed proton radioa...The β-delayed proton decay of 147Er is studied experimentally using the 58 Ni+92Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the β-delayed proton radioactivities both from the vδl/2 ground state and the vh11/2 isomer in 147 Er are identified by proton-7 coincidence measurements. By analyzing the time distribution of the 4+ → 2+-γ transition in the grand-daughter nucleus 146Dy, a half-life of 1.6 ± 0.2s is determined for the Vh11/2 isomer in 147 Er. The half-life for the ground state of 147Er is estimated to be 3.2±1.2 s.展开更多
文摘鉴于国内核物理实验对高性能硅探测器有大量需求,而国外对中国进行技术封锁,满足实验需求的高性能探测器不易获得.中国科学院近代物理研究所在原有制备工艺基础上首次采用套刻技术,有效减少了光刻及腐蚀过程造成的Si O2沾污,大幅提高了探测器性能和成品率.本文对采用该工艺研制的300μm厚,有效面积50 mm×50 mm硅探测器进行电学性能测试和在束探测性能测试.探测器在-45 V耗尽电压下,其漏电流小于40 n A,对5 Me V左右的a粒子的能量分辨(σ)约为45 ke V.将该探测器作为能量沉积(ΔE)探测器,利用250 Me V/u的11C放射性束流及其在次级碳靶上的反应产物对探测器进行了探测性能测试.测试结果显示,该探测器对于C元素的电荷数Z的分辨为0.17,与文献中记录的国外生产的同类型探测器的实验数据(Z分辨0.19)相当,可以满足中高能放射性束实验对轻质量区粒子鉴别的要求.
基金Supported by the National Natural Science Foundation of China under Grant No.19975057,and the Chinese Academy of Sciences。
文摘The (EC+β^(+)) decay of ^(128)Ce was reinvestigated in the^(116)Sn (l6O, 4n) reaction by using a helium-jet tape transport system. The decay γ rays of ^(128)Ce were unambiguously described from those of ^(129)Ce after taking the comparing experiments of ^(16)O+^(116)Sn and ^(16)O+^(117)Sn. Based on x-γ and γ-γ coincidence measurements, a detailed (EC+β^(+)) decay scheme of ^(128)Ce has been proposed which modifies the previous one, and takes accounts of 100 observed γ-lines.
基金Supported by the Chinese Academy of Sciencesthe National Natural Science Foundation of China under Grant No.19475055.
文摘The nuclide ^(129)Ce was produced by a(^(16)O,4n)reaction on an enriched ^(117)Sn target.Reaction products were transported to a shielded location by using a helium-jet tape transport system.An activity of 4.1 min in chemically separated cerium sample was identified as ^(129)Ce.Based on x-γ-t andγ-γ-t coincidence measurements,the(EC+β+)decay scheme of ^(129)Ce was proposed,and takes accounts of 50 observedγ-lines.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10825522, 10735010 and 10575120, and the National Basic Research Program of China under Grant No 2007CB815001.
文摘The β-delayed proton decay of 147Er is studied experimentally using the 58 Ni+92Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the β-delayed proton radioactivities both from the vδl/2 ground state and the vh11/2 isomer in 147 Er are identified by proton-7 coincidence measurements. By analyzing the time distribution of the 4+ → 2+-γ transition in the grand-daughter nucleus 146Dy, a half-life of 1.6 ± 0.2s is determined for the Vh11/2 isomer in 147 Er. The half-life for the ground state of 147Er is estimated to be 3.2±1.2 s.
基金Supported by National Natural Science Foundation of China (10635080, 10675148) and Knowledge Innovation Project of Chinese Academy of Sciences (KJCX2-SW-No18, CXTD-J2005-1) The authors acknowledge the collaborators from domestic and foreign institutes or universities for their helpful discussions and advices. They are IHEP, USTC, Tsinghua Univ., Peking Univ., Nan- jing Univ., ITP, CCNU, SINAP, CIAE, Lanzhou Univ., and Duke Uinv., C0SY@ Jiilich.