21 Track information using the data of SSD the following analysis is based on the instruction of : Y.P. Zhang,P.-A. Loizeau Data structure of ﬁnal NTUPLE and a short description about how to use the silicon tracking system the data files used : run_0005.root, run_0006.root,......, run_0020.root, where the USTC-MRPC was settled at the same position. run_0021.root, the MRPC moved by 12mm.
22 Hits position profile on MRPC the profile is about 3cm x 2 cm the following analysis will base on these SSD position cuts and charge cuts
23 Tranverse profile-- efficiency vs position for MRPC#1 run0005-0020
24 Efficiency vs Position for MRPC#1 data file, run_0021.root edge effects 6mm-gap
37 edge effects the profile is also quite clear, and we can see that the beam hits between two strips of the MRPC
38 (2) pmt cuts: pmt-pair charge: q1+q2, q3+q4 take out 5% at the low range side, and take another 25% at the high range side time difference: T1-T2, T3-T4 2.5%, 2.5% position difference: (T1-T2)-(T3-T4) 2.5%, 2.5% time of flight: ((T3+T4)-(T1+T2))/4 0.5%, 0.5%