新型涂硼热中子MWPC探测器的时间信号读出方法

Readout of the time signals of the MWPC detector with boron sensitive thermal neutron

基于^(10)B薄膜的二维灵敏探测器是新近发展起来的热中子探测器,其灵敏面积大,时间和位置分辨好,n/γ抑制能力高,抗辐射能力强,可二维读出且具有良好的耐计数能力。针对新型的涂硼灵敏热中子多丝正比(MWPC)探测器,在延迟线时间差方法的基础上,提出一种中子击中位置数字信息的读出方法,并设计NIM读出插件用以验证该方法对于二维中子探测位置信息的读出能力。测试结果表明,本方法能完成4通道探测器信号的实时测量,其时间测量精度好于50ps。结合FPGA片上系统实时数据控制和处理技术,单插件可支持最高1.3MHz的探测计数率。

The two dimensional sensitive detector based on l0B film is a newly developed thermal neutron detector with the advantages of large sensitive area, good time and position resolution, high n/γ inhibition ability, strong ability of anti-radiation, two-dimensional readout and good resistance to the count rate capability. So it is important to carry out the study of the readout method of the two-dimensional position sensitive neutron detector based on the B neutron transfer layer and MWPC structure. In this paper, a readout board based on delay-line readout method is presented. By measuring the time difference between the arri- ving signals on both sides of delay-line, the original position can be well recovered. By applying a hardwire filter in FPGA, the da- ta rate needs to be transferred can be reduced remarkably. The RMS of the TDC is less than 50 ps. The integral nonlinearity is better than 1.1 LSB, the differential non-linearity is better than 0.5 LB3. ＂The board achieves event rates of 1.3 MHz for periodic signals and the data can be transferred by Gbit ethernet daughter board simultaneously.