Status of the pulsed low energy positron beam system (PLEPS) at the Munich Research Reactor FRM-II
Status of the pulsed low energy positron beam system (PLEPS) at the Munich Research Reactor FRM-II
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DOI：
10.1016/j.apsusc.2008.05.307
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发表时间：
2008-10
影响因子：
6.7
通讯作者：
P. Sperr;W. Egger;G. Kögel;G. Dollinger;C. Hugenschmidt;R. Repper;C. Piochacz
中科院分区：
文献类型：
--
作者：
P. Sperr;W. Egger;G. Kögel;G. Dollinger;C. Hugenschmidt;R. Repper;C. Piochacz
慕尼黑脉冲低能正电子束系统（PLEPS）现已安装在慕尼黑研究堆FRM-II的高强度正电子源（NEPOMUC）上。为了提高系统的性能，进行了几项改进：安装了两个额外的共线检测器端口。因此，除了正常的寿命测量，现在可以同时进行多普勒展宽，符合多普勒展宽和年龄动量相关实验。还包括一个额外的斩波器，以周期性地抑制脉冲，从而延长20 ns的标准时间窗口，以实现更长寿命的精确测量。2007年5月和7月进行了第一次测试实验。在所有脉冲元件工作的情况下，我们获得了每秒1.4× 104个计数的计数率。总的时间分辨率（脉冲和探测器）约为240 ps（FWHM），峰本底比高达6×103：1。
The Munich pulsed low energy positron beam system (PLEPS) is now installed at the high intensity positron source (NEPOMUC) at the Munich Research Reactor FRM-II. In order to enhance the performance of the system several improvements have been implemented: two additional collinear detector ports have been installed. Therefore in addition to the normal lifetime measurements it is now possible to simultaneously perform Doppler-broadening, coincident Doppler-broadening and age momentum correlation experiments. An additional chopper was included to periodically suppress pulses and therefore to extend the standard time window of 20ns for precise measurements of longer lifetimes. First test-experiments have been performed in May and July 2007. With all pulsing components in operation we achieved a count-rate of 1.4×104counts per second. The total time resolution (pulsing and detector) was about 240ps (FWHM) with a peak to background ratio up to 6×103:1.