GSI Forum
GSI Helmholtzzentrum für Schwerionenforschung

Home » NUSTAR » NUSTAR PRESPEC » prespec git updates (Post here if you pushed your changes to the agatagsi@lx-pool.gsi.de:git/prespec repository and you want to make everybody aware of the new features you added)
Re: prespec git updates [message #17592 is a reply to message #17158] Thu, 27 November 2014 21:26 Go to previous messageGo to previous message
miree is currently offline  miree
Messages: 71
Registered: June 2014
continuous participant
From: *188.107.pools.vodafone-ip.de
There is a new processor for the mutual alignment of correlated signals. It can determine a set of offsets, such that all differences between pairs of signals will be zero.

One possible application of this: Consider the time signals of a LYCCA ToF detector. These signals have an offset with respect to each other, because of slightly different cable length (and maybe other reasons). As a consequence, if a particle hits the detector, Then signal from PMT_a will come not exactly at the same time as the signal from PMT_b, even if both signals were induced by the same particle. This offset is of course the same for each event. The processor CircularMembraneScintillator takes these offsets into account. But in practice, these offsets tend to induce difficulties in the calibration. Therefore, it might make sense to align the time signals before feeding them into the final processing.


processor ToFstart/SignalAlignment UTILS.InterSignalAlignment
	INPUT[0:15]     <-   LyccaTargetTofCrate.mhtdc0[0:15]
	INPUT[16:31]    <-   LyccaTargetTofCrate.mhtdc1[16:31]
	
	display INPUT_DIFFERENCES  10000,-5000,5000
	display OUTPUT_DIFFERENCES 10000,-5000,5000
end

# use output of the time alignment instead of the raw data
processor Lycca/ToFStart/Preproc   UTILS.MhTdcPreprocessor
	input[0:31]     <-   ToFstart/SignalAlignment.OUTPUT[0:31]
end


The parameter file for the InterSignalAlignment might look like this:
NUM_SIGNALS              		32
NUM_BINS                 		8000
BIN_WIDTH                 		1
CALIBRATE                		1
WRITE_INTERVAL             		1000

Where the most important parameter is NUM_SIGNALS (32 PMTs in this case). The other parameters are for tuning the automatic determination of the offsets. Look into the header file for detailed description.

I've tried out a new style of writing the processor code: I wrote every in/output,parameter,etc. in CAPITAL letters. The reasoning behind this: Trying to avoid the common mistake, that one accidentally writes
num_signals
when actually
parameter(num_signals)
would be correct. The capitals are clearly enums and no normal variables.

 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Multihit TDCs in the PreSPEC setup (CAENv1290)
Next Topic: LYCCA ToF scintillators
Goto Forum:
  


Current Time: Tue Dec 03 01:03:19 CET 2024

Total time taken to generate the page: 0.00799 seconds