1、LHAASO:Large High Altitude Air Shower Observatory,大型高海拔空气簇射观测站国家发改委“十二五”规划项目WCDA:Water Cherenkov Detector Array,水切伦科夫探测器阵列主要任务主要任务指标需求指标需求时间测量Bin size 1 ns 时间测量分辨率(RMS)0.5 ns 电荷测量动态范围S.P.E.-4000 P.E.S.PE电荷量480 fC电荷测量分辨率(%)30%S.P.E.;3%4000P.E.通道数3150n 全广角探测百GeV以上的EASn 探测粒子前锋面到达时间n 探测粒子电荷,判断粒子种类n 测量范围
2、:14000 P.E.n 三个水池,3150个PMT主要技术要点分布式电子学结构大动态范围电荷和时间的高精度测量大空间范围内多个模块的高精度时钟同步多个通道数据和时钟的高速传输两个水池各900个PMT,第三个水池1350个PMT每个读出电子学(FEE)负责9个PMTFEE主要技术路线电荷分段测量:RC2模拟成型+数字寻峰时间测量:双阈甄别的前沿定时+基于时钟分相的FPGA-TDC时钟调相基于White Rabbit协议以及对称结构的FPGA-PLL基于SiTCP的数据打包,光纤传输4个FEE以附件搭建的机箱20个PMT(CR365*4和XP1805*16)主要目的:验证系统对实际PMT的测量数
3、据正确性验证系统工作稳定性转换曲线:各通道采用多项式拟合建立转换关系1301335004000102103FEE 16 Charge TransformInput Charge/P.E.ADC Count/LSB1301335004000102103FEE 17 Charge TransformInput Charge/P.E.ADC Count/LSB1301335004000102103FEE 18 Charge TransformInput Charge/P.E.ADC Count/LSB1301335004000102103FEE 19 Charge TransformInput Ch
4、arge/P.E.ADC Count/LSB电荷精度:满足性能指标13013350040000246810FEE 16 Charge ResolutionInput Charge/P.E.Resolution/%13013350040000246810FEE 17 Charge ResolutionInput Charge/P.E.Resolution/%13013350040000246810FEE 18 Charge ResolutionInput Charge/P.E.Resolution/%13013350040000246810FEE 19 Charge ResolutionInpu
5、t Charge/P.E.Resolution/%时间精度:线延迟法测试,满足性能指标130133500400000.050.10.150.20.25FEE 16 Time ResolutionInput Charge/P.E.Resolution/ns130133500400000.050.10.150.20.25FEE 17 Time ResolutionInput Charge/P.E.Resolution/ns130133500400000.050.10.150.20.25FEE 18 Time ResolutionInput Charge/P.E.Resolution/ns13013
6、3500400000.050.10.150.20.25FEE 19 Time ResolutionInput Charge/P.E.Resolution/nsTime Walk:通过多项式拟合建立与输入电荷之间的修正曲线1301335004000687072747678808284FEE 16 Time WalkInput Charge/P.E.Time Walk/ns1301335004000278280282284286288290292294FEE 17 Time WalkInput Charge/P.E.Time Walk/ns13013350040006870727476788082
7、FEE 18 Time WalkInput Charge/P.E.Time Walk/ns1301335004000687072747678808284FEE 19 Time WalkInput Charge/P.E.Time Walk/ns通过QDC标定触发信号与PMT光强的关系再在同样条件下用FEE测量电荷分辨率在大于5 P.E.处基本服从1/N1/2规律,单光电子触发率服从泊松分布4000 P.E.5%30133 P.E.区间阳极和打拿极测量信号FEE 阳极通道和打拿极通道增益比通过电子学测试拟合可得0.8710QDC标定GRPMT=31.0779FEE实测GRM=26.7454与31.
8、07790.8710=27.0689相差1.2%具体转换关系需要PMT的增益-光子数转换曲线和FEE的电荷-LSB转换曲线二次修正保护电路测试50V,100ns脉冲,长时间冲击网络连接及传输稳定性测试通过商用交换机及双网卡PC实现系统的远程控制及数据传输FEE可正确接收Master WR的时钟并调相连接及传输稳定(测试时间100h)电子学温漂测试-1060下可稳定工作电荷温漂3%时间精度修正后50ps时钟调相 RMS30ps阈值自动标定标定精度好于5%保护电路测试-10010203040506015001550160016501700the ch 10Temperature(C)skew(ps)