The Measurement of the Cross Section of the Reaction ￣(204)Hg(n,￣3He+2Pn)￣(202)Pt

首次报道￣（204）（n，￣3HE＋2Pn）￣（202）PT核反应截面的实验测量结果为1μb量级，证实了中子截面系统学研究结果的可靠性。实验中所用的快中子源（E＿n＝21MEV）是利用能量25MEV、流强10μA质子轰击1MM厚铍靶而产生的；反应产物放射性PT是通过化学分离法而得到的；γ能谱测量是采用低本底HPgEγ谱仪。The cross section of the reaction ￣(204)Hg(n,￣3He+2Pn)￣(202)Pt was measured For theFirst time to be abeut 1μb.The Fart neutrons( MeV)were produced by bombarding 1 mmthick,metallic beryllium plate with 25 MeV proton beam of 10 μA From the cyclotron.The radioiso-tope of the platinum was separated by chemical method.The γ-rays were detected by HPGe γ-ray spectrometer.国家自然科学基金和中国科学院所长基

实验测定~(183)0s的Q_(EC)值

用39 MeV-α粒子轰击天然钨靶产生了~(183)Os测量了~(183)Os衰变的γ-β符合谱,确定了β~+能谱的端点能量。最终提取出~(183)Os衰变的Q_(EC)值:Q_(EC)=2.24±0.10 MeV,与系统学的估计值:2.304±0.10MeV在误差范围内相符

新丰中子同位素:~(186)Hf

在兰州重离子加速器（ＦＤＵＬ）上，用６０ＭｅＶ／μ１８Ｏ离子轰击厚天然钨靶，通过多核子转移反应产生１８６Ｈｆ。使用放射化学分离技术从钨和反应产物混和物中分离出铪，并由ＨＰＧｅ探测器测量铪样品的活性．观测到了１８６Ｈｆ的子体１８６Ｔａ的７３７，５ｋｅＶＹ射线的增长、衰变行为，结果表明，本实验首次合成并鉴别了新丰中子同位素１８６Ｈｆ，测得它的半衰期为（２．６±１．２）ｍｉｎ。The radioactive nuclide 186Hf has been produced via multinucleon transfer reaction by 60 MeV / u 18 O ion irradiation of the natural tungsten. The radiochemical separation was performed to isolate the hafnium from tungsten and the complex mixture of the reaction products. The activity of the hafnium was measured using a HPGe detector The new neutron-rich isotope 186Hf has been identified for the first time by measuring the growth and decay of the 737.5keV - ray from its daughter 186Ta. The half-life of186H...国家自然科学基金,中国科学院资

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies