MainPage:Nuclear:NPS:PWO:LightYield

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Instructions to scan LY

(THIS IS A PRELIMINARY VERSION ONLY)

1) Set the freezer temperature (controller fixed on the wall, on the side of the freezer): A) Hold the button SET for 3 seconds B) Change the temperature by pressing up/down buttons C) Hold the button SET for 3 seconds to save the new temperature D) Wait more than 5 hours (?) to stabilize temperature (keep HV on at all time to stabilize PMT also) E) Keep one terminal always logging the temperature in the Control computer: cd thermometer ./MlogT F) Check temperature at Control computer: cd thermometer ./MplotT (Ctrl+c to stop the script)

2) Prepare electronics: A) On the NIM module N1470, turn on the trigger (ch0) and the signal (ch2) HV. It is set to keep -760V (trigger PMT) and -2300V (signal PMT), draining approximately 670 and 1035 uA respectively. B) If gate width change is required, look in the scope the width of the gate. You change it by turning the hidden screw "width" in the NIM module 794, on the 2nd channel. C) Make sure the trigger and the signal cables are connected to the ADC.

3) Prepare CODA (DAQ computer): A) Options -> Limits -> Set Time Limit B) Set the time of each run, i.e., the time each step along the crystal where LY will be measured.

4) Run motor to scan (CONTROL computer) and start CODA when prompted (DAQ): A) In a terminal, go to directory motor. Execute the command: ./scan_12cm_step1cm_90min (or equivalent for the test you want - be consistent with the time set in CODA!) B) If requested, type the password. C) Make sure you hear the motor moving D) When the terminal prompts that the scan will start in 10 seconds, switch to the DAQ computer and start coda USING: Option -> Enable Auto Mode

5) Converting data A) In a terminal at DAQ computer, convert the files created (to exemplify, let's say runs ranging from 2000 to 2010): ./convertRange.sh 2000 2010 (Enter password when prompted to transfer data to Control computer) B) In a terminal at Control computer, unzip the transferred file: cd data unzip 2000.zip C) Convert the data to ROOT (for exemple, run 2000): root -l -q 'HEX2root.C(2000)

6) Analyze data (important to keep consistency, so we can inter-compare crystals): A) Fit the peaks with root (supposing you used the ADC channel 1, otherwise adjust): root -l 2000.root T->Draw("ch1>>(1201,0,1200)"); [...] (I am going to write a script to do that automatically)