Preliminary Analysis of mTPC pulser data D. A. Jensen May 30, 2007

Sets/Runs for analysis Several sets of data from the μTPC in PAB have been written to disk where the data has been trigger by a pulser. Some of the data is pure noise, some of the data includes ‘tracks’ which are based on a pulser signal. For convenience of looking at the data, I have gathered several of the runs, as defined in the DAQ system at PAB into sets. The correspondence is as follows:

Set 4 1R048_E001_T dat 1 – noise, 2 – pulser track, 3 – no connection 2R048_E002_T dat same 3R048_E003_T dat same 4R049_E001_T dat 1 – noise, 2 - noise, 3 pulser tracj 5R049_E002_T dat same 6R049_E003_T dat same 7R049_E005_T dat same 8R050_E001_T dat all 3 views are noise 9R050_E003_T dat same 10R050_E004_T dat 11R050_E005_T dat

Set 5 events 1R060_E001_T dat 2R061_E001_T dat check runs 3R061_E002_T dat same 4R061_E003_T dat same 5R062_E001_T dat same, but switch box unplugged 6R062_E002_T dat same 7R063_E001_T dat 2kv on TPC, 0 wire bias voltage 8R063_E002_T dat same 9R064_E001_T dat same as above, but fibers pulled out of light pulser 10R064_E002_T dat same 11R065_E001_T dat uv fiber plugged back in 12R065_E002_T dat same 13R066_E001_T dat hv off 14R067_E001_T dat hv at 4 kv 15R067_E002_T dat same 16R068_E001_T dat hv at 4kv, closer to lamp 17R068_E002_T dat same 18R069_E001_T dat hv at 4 kv, fiber out 19R069_E002_T dat same

The next two figures show the raw signals Only the data from readout plane 1 is shown, the other two planes are esentially identical. –First as a ‘mountain plot’ –Second as a ‘Lego plot’

Raw signals

Noise Spectrum, σ = 1.2

An event with a pulser track The next plot shows an event with 2 views of noise and one view with a pulser ‘track’ - An alternative presentation of the data ( this is a ~4 MByte file ! )

A 3-signal ‘Mountian’ plot, view 3 – for reconstruction.

The same event reconstructed with thresholds of 7 and 14 counts respectively

Comments on track finding As can be seen from the preceeding plots, The pulse shape ( overshoot ! ) can have a profound effect on the reconstruction effort. One can also supress finding signals in a window after a pulse that has been found, but this could be a problem for finding tracks that are near. Of course, this is pulser data…. So should not start drawing conclustions

Some more detailed ‘looks’ I have prepared some.ps files of plots of the data in various forms, including mountian, lego, and individulal wire time plots. They are on the docdb. I have continued to experiment with how to visualize the data. A more recent effort has been to prepare contour plots. Along with the contour plots are individual wire plots that help make clear what is shown and the scales.

Contour Plot details Refer to the file cont_s5e17.ps Contour plot ranges and steps ( note: 0 offset 400) view – 600 in 10 steps view – 550 in 17 steps view – 450 in 15 steps These scales set to make ‘pretty pictures’ and might clearly be set differently. For different studies, they definitely must be set to ‘appropriate’ values For each contour plot, there are 2 wire plots to help make clear the details of the contour plot.