Qweak scintillator prototype cosmic test (2)

1. Change the trigger paddles from two 6"x6" paddles to one 1"x1" paddle and one 1"x6" paddle, to gain better position resolution of the cosmic test. Below are a few photos of the prototype setting.

I. Overview of the SCIN prototype



II. Trigger paddles



III. Triangular lightguide and 3" PMT



VI. Electronics and DAQ



2. Taking cosmic data at the center and each end of SCIN to measure the number of photoelectrons/cosmic events, and the time resolution. Plan to take 50k events for each cosmic run to gain enough stats. It takes longer time to collect the same amount of cosmic events comparing to 6"x6" trigger paddles. Expect to finish the measurement at early next week. Here are the new ADC and TDC histograms I got when using one 1"x1" and one 1"x 6" paddle.

I. ADC histogram of cosmic run at Z=115 cm and Y= center



II. TDC histogram of cosmic run at Z=115 cm and Y= center