摘要
液氦时间投影室(ALETHEIA)是一个原创的低质量(100 MeV/c^(2)—10 GeV/c^(2))暗物质探测装置.入射粒子在液氦时间投影室中与液氦发生相互作用会产生80 nm长的闪烁光.目前尚无商用光电读出器件可以直接高效读取该闪烁光.为此,需要波长迁移剂(wavelength shifter)先将其转换为可见光,然后再用商用光电读出器件探测之.在参考国际相关类似涂敷试验装置的基础上,利用改进的气相沉积法成功地在直径和高度均为10 cm的圆柱形聚四氟乙烯(PTFE)容器内壁涂敷1.50—3.02μm.厚的TPB(tetraphenyl butadiene, 1,1,4,4-四苯基-1,3-丁二烯)涂层.此工艺方法对其他需要在圆柱形探测器内壁涂敷TPB或者其他类似材料的试验具有参考价值.本文对TPB涂层的涂敷原理、盛放TPB粉末的源的设计、涂敷工艺、涂层厚度监测等方面进行阐述.
ALETHEIA(a liquid hElium time projection cHambEr In dark matter)project is an originally creative dark matter experiment aiming to search for low-mass(100 MeV/c^(2)–10 GeV/c^(2))WIMPs.While there have existed more than ten experiments doing research on low-mass WIMPs,the ALETHEIA is supposed to grow up to be a leading project worldwide due to many unique advantages,including but are not limited to extremely low intrinsic backgrounds,easy purification,and strong potential capability of signal/background discrimination.Owing to the project’s original creativity,there has existed no direct experience of building such a detector yet;consequently,we have to launch a set of R&D programs from scratch,including the TPB coating process conveyed in this paper.An incident particle that hits a liquid helium detector would generate 80-nm-long scintillation.There are currently no commercially available photon detectors capable of efficiently detecting the scintillation light and a wavelength converter must be used to convert the 80-nm-long scintillator into visible light.Silicon photomultipliers(SiPMs)can then be implemented to detect the 450-nm-wavelength light.The TPB(Tetraphenyl Butadiene,1,1,4,4-tetraphenyl-1,3-butadiene)is widely used for realizing the conversion.Although in thedark matter experiment using argon pulse-shape discrimination(DEAP),2.3-μm-thick TPB is successfully coated on the inner wall of the sphere with a radius of 85 cm,we cannot mimic the whole process in our experiment directly out of the two following reasons:(a)our detector shape is cylindrical,not spherical,and(b)the diameter of the current detector prototype is only 10 cm,while the one of the DEAP detectors is as large as 1.7-meter.Consequently,we must design and build an appropriate coating apparatus suitable for our detector.Owing to the existence of necessary auxiliary parts(such as cables for heating and temperature sensors),on which some vapored TPB molecules would be deposited when the coating is in progress.As a result,a blind spot on t
作者
欧阳泽邦
彭朝华
郑健
梁卓
周江枫
赵修良
廖俊辉
Ouyang Ze-Bang;Peng Zhao-Hua;Zheng Jian;Liang Zhuo;Zhou Jiang-Feng;Zhao Xiu-Liang;Liao Jun-Hui(The School of Nuclear Technology,University of South China,Hengyang 421001,China;Institute of Nuclear Physics,China Institute of Atomic Energy,Beijing 102413,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第22期377-386,共10页
Acta Physica Sinica
基金
中国原子能科学研究院院长基金(批准号:YZ202101-WL)
国家自然科学基金资助项目(批准号:12005098)资助的课题。
