GSI Forum: NUSTAR PRESPEC » FRS Calibration Issue

Home » NUSTAR » NUSTAR PRESPEC » FRS Calibration Issue

Show: Today's Messages :: Polls :: Message Navigator

FRS Calibration Issue [message #17090]

Tue, 22 July 2014 19:14

SMilne
Messages: 30
Registered: July 2014
Location: York

continuous participant

From: *york.ac.uk

Hi all,

So, I have been experiencing some weird issues with the final FRS Calibration step for a while now, which has been giving me a skewed 'Z vs A/Q plot' (see attached), but first, I thought I should explain all the steps I have taken prior to this, just in case I've made any mistakes along the way.

The order in which I have performed the FRS calibrations:
1) TPC - Position corrections, check sumgates, etc.
2) TOF - TOF Calibration, beta calibration, etc. using LISE++ Files
3) MUSIC - Aligning raw energy losses, etc.

TPC Calibrations
- Performed position calibrations for TPC21, TPC22, TPC41 and TPC42 using the fiber mask run files.
- Offsets and gains extracted from linear fits to plots of 'correct fiber positions vs raw positions', for the x and y positions.
- Replayed data, all worked fine and centroids are all within ~0.05mm of the correct position. (i.e. see attached example of 'y vs x')
- Checked/adjusted sumgates for experimental data, all fine.

TOF Calibrations
- Produced 4 LISE++ files, including all degrader thickness offsets etc. for 4 different settings in this experiment: 43Ti (isomer calibration setting), 46Ti, 46V, 46Cr
- Extracted LISE++ TOF and Beta values from the 'goodies option' on the tool bar, selecting TOF between S2 and S4 scintillator (which also gave the distance).
- (Beta was found from distance/TOF [this may very well be incorrect, but I can't see how else it can be extracted from LISE++, but then again, I am no expert])
- I then extracted the scintillator TOF_LL and TOF_RR for all these nuclei, from the raw spectra, then plotted 'LISE++ TOF vs raw TOF_LL(or raw TOF_RR)', and from the linear fits, obtained offset and gain coeficients which I put into the 'TofSystem.cal' file.
- Replayed the data for the 4 settings, measured the TOF in the TOF spectrum for all 4 nuclei, which all matched the LISE++ values within 0.4ns.
- I then plotted '(LISE++ Beta x Measured TOF) vs LISE++ Beta', and from the linear fit, the offset(-distance) and gain(time offset) were found and added to the 'TofSystem.par' file.
- Replayed the data, then measured beta for all settings, and all were within 0.16% of the LISE++ beta value.

MUSIC Calibrations [where the issues occur]
- Aligned all the raw energy spectra to an arbitrary value of 900 for the 46Ti setting, changing the gains in 'Music1.cal' and 'Music2.cal'.
- Replayed the data and measured the centroid of the combined raw energy losses for MUSIC1 and MUSIC2 for all 4 settings.
- Plotted 'aligned MUSIC1(or MUSIC2) energy loss vs LISE++ Beta' (see attached) and extraced a, b and c from quadratic fit (a + b*\beta + c*(\beta)^2).
- All seemed fine and added these into the 'FrsId.cal' file then replayed the 46Ti data.
- The end result is attached as well as the PID before this calibration (leaving an old calibration already in place). [where the old PID plot is using an incorrect 'Z_in 35', to get the '46Ti blob' at Z~22 and the new one is using the correct 'Z_in 22' in the FrsId.par file].

Can anyone see where I've went wrong or perhaps where I am mistaken in my current calibration procedure. If you require any more spectra etc. related to the problem, let me know.

Many thanks,
Scott

Attachment: TPC42-yvsx.png
(Size: 51.02KB, Downloaded 486 times)
Attachment: FRS-MUSIC1-Beta.png
(Size: 39.96KB, Downloaded 485 times)
Attachment: FRS-MUSIC2-Beta.png
(Size: 46.66KB, Downloaded 474 times)
Attachment: 46Ti-SkewedPID.png
(Size: 108.46KB, Downloaded 477 times)
Attachment: 46Ti-OldPID.png
(Size: 73.24KB, Downloaded 476 times)

Report message to a moderator

[Message index]

		FRS Calibration Issue By: SMilne on Tue, 22 July 2014 19:14
		Re: FRS Calibration Issue By: mlcortes on Thu, 24 July 2014 09:48
		Re: FRS Calibration Issue By: SMilne on Thu, 24 July 2014 14:52
		Re: FRS Calibration Issue By: mlcortes on Thu, 24 July 2014 15:19
		Re: FRS Calibration Issue By: SMilne on Wed, 17 September 2014 14:22
		Re: FRS Calibration Issue By: mlcortes on Wed, 17 September 2014 14:34
		Re: FRS Calibration Issue By: SMilne on Wed, 17 September 2014 16:01
		Re: FRS Calibration Issue By: mlcortes on Fri, 19 September 2014 08:01
		Re: FRS Calibration Issue By: SMilne on Thu, 24 July 2014 18:06
		Re: FRS Calibration Issue By: SMilne on Fri, 19 September 2014 15:31
		Re: FRS Calibration Issue By: mlcortes on Sun, 21 September 2014 21:59
		Re: FRS Calibration Issue By: SMilne on Mon, 22 September 2014 19:50
		Re: FRS Calibration Issue By: mlcortes on Wed, 24 September 2014 00:10
		Re: FRS Calibration Issue By: SMilne on Wed, 24 September 2014 12:05
		Re: FRS Calibration Issue By: SMilne on Wed, 24 September 2014 12:14
		Re: FRS Calibration Issue By: mlcortes on Wed, 14 January 2015 09:35
		Re: FRS Calibration Issue By: SMilne on Fri, 16 January 2015 01:45
		Re: FRS Calibration Issue By: SMilne on Fri, 16 January 2015 01:53
		Re: FRS Calibration Issue By: mlcortes on Fri, 16 January 2015 13:49
		Re: FRS Calibration Issue By: SMilne on Fri, 16 January 2015 19:35
		Re: FRS Calibration Issue By: mlcortes on Mon, 19 January 2015 13:10
		Re: FRS Calibration Issue By: SMilne on Mon, 19 January 2015 19:08
		Re: FRS Calibration Issue By: mlcortes on Wed, 28 January 2015 10:10
		Re: FRS Calibration Issue By: SMilne on Tue, 10 February 2015 17:09
		Re: FRS Calibration Issue By: mlcortes on Thu, 12 February 2015 10:05
		Re: FRS Calibration Issue By: SMilne on Thu, 12 February 2015 13:59
		Re: FRS Calibration Issue By: mlcortes on Tue, 17 February 2015 12:06
		Re: FRS Calibration Issue By: SMilne on Tue, 17 February 2015 13:23
		Re: FRS Calibration Issue By: mlcortes on Tue, 17 February 2015 15:31
		Re: FRS Calibration Issue By: SMilne on Tue, 17 February 2015 17:20
		Re: FRS Calibration Issue By: mlcortes on Tue, 17 February 2015 17:29
		Re: FRS Calibration Issue By: SMilne on Thu, 26 February 2015 01:12
		Re: FRS Calibration Issue By: mlcortes on Mon, 02 March 2015 17:54
		Re: FRS Calibration Issue By: SMilne on Wed, 20 May 2015 12:19
		Re: FRS Calibration Issue By: SMilne on Fri, 22 May 2015 10:36
		Re: FRS Calibration Issue By: mlcortes on Fri, 22 May 2015 13:27

Previous Topic:	Position calculations on start/stop scintillators
Next Topic:	Strict-merge option

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Nov 27 21:22:56 CET 2024

Total time taken to generate the page: 0.00721 seconds