QtPALS Files

Changelog

• QtPALS 181016 - eval board5 support fixed, firmware with latch delay and spike fix included, 2,3,4 detector support
• QtPals 180102 - added settings save and load

INSTALATION

HW: pulses max +/- 0.5V, use atenuators for bigger pulses (for example picotech TA050: Attenuator Set) connect signals to DRS4 card as follows:

• Ch1 - Start
• Ch2 - Stop
• Ch3 - Stop2 (optional for 3detector setup)
• Ch4 - trigger input (in 4D mode, Start2)

You can now choose detectors and channels in QtPALS individualy

As triger use sum signal from BK OUT CFD (Ortec 583,584), it shoud be done using 20dB ateunators and standard BNC Tee. CFD windows are set like in analog setup, but little bit more wide

External trigger is needed for original PSI DRS4 firmware, after updating FPGA firmware external trigger is no more needed. Use firmware for your card from https://sourceforge.net/p/qtpals/code/ci/quadro/tree/FPGA/ directory

!!! new firmware will erase old calibration data therefore after firmware update run new callibration !!!

Run DRS Oscilloscope, set card to +/-5V, 5.12GS/s sampling and do amplitude and time calibrations; Check signal and trigger with DRS4 Oscilloscope, note Trigger delay and amplitude Use DRS Osciloscope config info button in board section to check if firmware was updated (eval5 -> fw 30001, eval4 -> fw 17667)

Close DRS Osciloscope and run QtPALS

1.) Options->Configuration - choose 2D or 3D (two detectors or three detector setup) 2.) set INV according to pulses from detectors, chceck it for negative pulses 3.) set CFD value (0.2 for anode outputs, 0.083 for bipolar dynode outputs) 4.) set trigger like in DRS osciloscope 5.) Start Stop windows set later, according to measured energy histograms 6.) run QtPALS (play button) and observe energy historams E1,E2, respect. E3, set energy windows according to measured energy histograms in configuration window 7.) Close QtPALS application and reopen it. 8.) Click on New button and select directory where lifetime spectrums will be stored 9.) Run application. Default counts is set to 1e6, you can change it in all histogram windows, by setting NTotal 10.) After finishing measurement store it by Save button, you can save spectral individually in bottom menu in different formats.

Results:

2D mode

• T1 - Ch1 start, Ch2 stop (shifted to zero time counted from T4)
• T2 - Ch2 start, Ch1 stop (shifted to zero time counted from T5)
• T3 - sum of T1 and T2
• T4 - Ch1 start, Ch2 stop used to calculate zero time, is restarted every 1e4 counts
• T5 - Ch2 start, Ch1 stop used to calculate zero time, is restarted every 1e4 counts
• T6 - Ch1 - Ch2 spectrum

3D mode

In 3D and 4D mode Ch2-Ch3 filter (T5,T6) must be set to get it work
(Options->Energy->Stop-Stop time window)

• T1 - Ch1 start, Ch2 stop
• T2 - Ch1 start, Ch3 stop
• T3 - Ch1 start, (Ch2+Ch3)/2 stop, Ch2-Ch3 filter On
• T4 - Ch1 start, (Ch2+Ch3)/2 stop, Ch2-Ch3 filter Off
• T5 - Ch2(stop)-Ch3(stop) filter
• T6 - Ch2-Ch3

Shape filters

To enable shape filters S1 .. S4, collect > 1E7 counts and click SHFinit, you can then store filter and next time reload it with SHFload, Reset will disable filter

References

http://iopscience.iop.org/1742-6596/505/1/012044/ doi:10.1088/1742-6596/505/1/012044