LISTSERV mailing list manager LISTSERV 16.5

Help for HPS-SOFTWARE Archives


HPS-SOFTWARE Archives

HPS-SOFTWARE Archives


HPS-SOFTWARE@LISTSERV.SLAC.STANFORD.EDU


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Monospaced Font

LISTSERV Archives

LISTSERV Archives

HPS-SOFTWARE Home

HPS-SOFTWARE Home

HPS-SOFTWARE  April 2014

HPS-SOFTWARE April 2014

Subject:

Re: [Hps-ecal] HPS Ecal signals parametrization

From:

Gabriel CHARLES <[log in to unmask]>

Reply-To:

Software for the Heavy Photon Search Experiment <[log in to unmask]>

Date:

Thu, 3 Apr 2014 22:55:21 +0200

Content-Type:

multipart/mixed

Parts/Attachments:

Parts/Attachments

text/plain (118 lines) , SimulationCrysAPD.eps (118 lines)

Could you both provide an average value of chi square that the
different parametrization can be compared easily, please ?

Also, from the simulation it appears that the rising edge could be
present. In attachment you will find a picture with two plots. The top
one corresponds to the signal after the crystal and the APD, that is the
input of the preamplifier.
  It is obtained by the convolution of the signal of the crystal and the
APD. The crystal response is composed of the sum of two decreasing
exponential governed by different time constants. The APD transfert
function is given by the bottom plot (sorry for the wrong Y axis units).

  There is no reason for the preamplifier to reduce the tail.

  I think that if there is no huge difference between the chi square it
would be better to keep the two gaussian function.

---
Gabriel CHARLES
Institut de Physique Nucléaire d'Orsay

On Thu, 3 Apr 2014 13:15:00 -0700 (PDT), Sho Uemura wrote:
> I tried two more parametrizations. These are parametrizations
> commonly used for the APV25 preamp that we use in the SVT.
>
> CR-RC: t*exp(-t/tp)
> 3-pole, or CR-RC-RC: t^2*exp(-t/tp)
>
> 3-pole seems to fit well, I think better than the asymmetric
> Gaussian. CR-RC seems no better than the Gaussian. Other
> parametrizations I tried (variations on CR-RC or 3-pole using more
> than one time constant) were degenerate with CR-RC or 3-pole, so I
> didn't include those plots.
>
> Plots attached are for 3-pole function. All plots for 3-pole and
> CR-RC, and the pyroot scripts I used, are online:
>
> http://www.slac.stanford.edu/~meeg/ecalpulsefit/
>
> I also see what you see, where there are 2 clusters in the
> distribution of shape parameters. I chose the center of the larger
> cluster (with the faster time constant) and refit all the events with
> this time constant fixed; those plots are named "fit2" and as
> expected
> they fit the faster pulses well and the slower pulses poorly.
>
> More data will help.
>
> I plotted the three parametrizations we have, see plot4.pdf attached.
> If we agree that the Gaussian has an unphysical rising edge, I think
> we should use 3-pole.
>
> On Tue, 1 Apr 2014, Andrea Celentano wrote:
>
>> Dear all,
>> here are some results about HPS Ecal signals parametrization.
>> I took data with the crystal placed vertically, APD gain 150, room
>> temperature. I put a threshold ~ 20 mV to keep only big enough
>> signals, out of the noise.
>> I acquired data with a 2.5Gs/s oscilloscope, 1 GHz bandwidth, 50 Ohm
>> input impedance.
>>
>> I used the same* configuration employed at JLab for cabling: 8m 3M
>> cable ---> passive splitter ---> 3m lemo cable.
>>
>> *actually I employed an 8 meters 3M cable instead of 7m because the
>> latter is not available here in Genova.
>>
>> Attached you find a postcript file with the results. (outGood.ps
>> shows the fit results covering some parts of the signal, outGood1.ps
>> no)
>>
>> - Neglect first blank page
>> - Pages from 2 to 32 are the 31 signals I got, with superimposed the
>> fit performed with the two-gaussians parametrization. Each chi2 fit is
>> performed independently.
>> Signals are in mV and ns.
>> Note that near ~ 100 ns there is probably a reflection due to some
>> impedance mismatch in the cables chain.
>> However, I am not using those points to fit. I am fitting the data
>> in between -200 ns and +80 ns. The function is then plotted in the
>> full time range.
>>
>> - Last page is a summary of the fits performed. Two 1d-histograms
>> are the distributions of the two time constants used in the
>> parametrization. Then I am plotting also their correlation, as well as
>> the correlation of the rise-time (par[1]) with the signal amplitude
>> (from the fit).
>>
>> I noted that the fit parameters Trise, Tfall are not distributed as
>> two gaussians. In particular, for Trise there is an accumulation of
>> events at ~ 5 ns and ~ 7 ns, correlated with corresponding Tfall at ~
>> 15 and ~20 ns. Actually, I see that, other than the amplitude, signals
>> do not have always the same shape: look, for example, at signals n.5
>> and n.6 (ps pages n.5 and n.6).
>>
>> Attached you find also the C implementation of the signal
>> parametrization, in form of a "double fun(double *x,double *par)"
>> used by ROOT when fitting trough TF1.
>> Finally, I am attaching also the raw data for the 31 signals I got,
>> so if you're interested you can play with different signal
>> parametrizations.
>>
>> I am planning to take more data these days.
>>
>>
>> Bests,
>>
>> Andrea
>>

########################################################################
Use REPLY-ALL to reply to list

To unsubscribe from the HPS-SOFTWARE list, click the following link:
https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=HPS-SOFTWARE&A=1

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

February 2024
January 2024
December 2023
November 2023
October 2023
September 2023
August 2023
July 2023
June 2023
May 2023
April 2023
March 2023
February 2023
January 2023
December 2022
November 2022
October 2022
September 2022
August 2022
June 2022
April 2022
March 2022
February 2022
January 2022
December 2021
November 2021
October 2021
September 2021
August 2021
July 2021
June 2021
May 2021
April 2021
March 2021
February 2021
January 2021
December 2020
November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011

ATOM RSS1 RSS2



LISTSERV.SLAC.STANFORD.EDU

Secured by F-Secure Anti-Virus CataList Email List Search Powered by the LISTSERV Email List Manager

Privacy Notice, Security Notice and Terms of Use