Primex Veto Banks

Raw Veto Banks

There are two Veto banks containing raw data. They are the ADC bank (VETOA) and TDC bank (VETOT). Below are the structure of each which is identical to all Primex raw data banks.

The contents of the banks are:

• id : pmt id
• val : ADC or TDC channel value

Reconstructed Veto Bank

The VETOHIT bank contains information for the reconstructed hit in the Veto counters. Instead of ADC and TDC information, it will have energy and time values. From the time diffference between the top and bottom pmts, a y-position will be determined. The x-position will be given by the counter id.

The contents of the bank are:

• id : counter id (not pmt id)
• E : average energy in the counter
• adc_ratio : ratio of the top and bottom ADC values
• t : average time from the counter
• tdiff : time difference between top and bottom pmts
• x : x-position in cm
• y : y-position in cm derived from time difference

For the i^th pmt, the time will be converted from the TDC channel by the equation

t_i = 0.5*T_i - t⁰_i

where t_i is the time in ns, T_i is the TDC, and t⁰_i is the time offset in ns which will be determined by calibrations.

The average time t in the VETOHIT bank will be found by the equation

where i is the index of the top pmt so i+10 gives the index of the bottom pmt, and id is the counter id which is 1-6 when i=1-6 (left counters) and 7-12 when i=21-26(right counters)

The time difference tdiff will be found by the equation

with the same explanation of the indices given directly above. Thus, tdiff is top pmt time subtracted by the bottom pmt time.