[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: GlueX-doc-829



Hi David:


Thanks for the feedback to both of you. Yes, it was unfortunate that we didn't pay much attention to the Veto ADC.  We are looking forward to your results from option 1.

Cheers and thanks again, Zisis...

On Jun 7, 2007, at 2:49 PM, David Lawrence wrote:


Hi Zisis,

   Just to give you an update:

   Simon and I spoke about the tagger timing calibration of the BCAL beam test data some more. The calibration was done using the veto paddle as a reference detector to line up all of the T-counters. I checked this and the T-counter/veto timing difference looks very flat as a function of T-counter id. However, the veto paddle itself does not have very good timing resolution due to timewalk. The timewalk can be a very big effect here because the point of conversion can happen anywhere within the paddle so there is a wide range of amplitudes that are independent of photon energy. Unfortunately, the veto ADC data seems to be bad so we cannot correct for timewalk in the veto.

   We have two options to try recalibrating the T-counters:

1.) Calibrate relative to the timewalk-corrected BCAL times
2.) Calibrate relative to neighboring T-counters using overlap regions

I think option 1.) would be the best way to go. We are going to work on that and should have something for you early next week.

Regards,
-David

David Lawrence wrote:

Hi Zisis,

   Simon and i spoke briefly about this on Friday afternoon and are planning to look into it a little more today. We'll let you know what we come up with.

Regards,
-David

Zisis Papandreou wrote:
Hi Matt and others:

I quickly put together a short document (GlueX-doc-829-v1) on Rafael's simulations with his standalone code on a single BCAL module.  They show the well-known 12% sampling fraction and the energy leakage from all four non-readout sides.  Many of these will be repeated by Blake and myself in the near future, and to greater detail.  This document is simply for quick look up at present and for future comparison of Blake's and Rafael's standalone codes.

Cheers, Zisis...

---
Dr. Zisis Papandreou |  email: zisis@uregina.ca <mailto:zisis@uregina.ca>
Department of Physics |  tel. : (306) 585-5379
University of Regina |  tel. : (306) 585-4149
Regina, SK  S4S 0A2 |  fax. : (306) 585-5659




-- 

------------------------------------------------------------------------
 David Lawrence Ph.D.
 Staff Scientist                 Office: (757)269-5567   [[[  [   [ [        Jefferson Lab                   Pager:  (757)584-5567   [  [ [ [ [ [    http://www.jlab.org/~davidl     davidl@jlab.org         [[[  [[ [[ [[[
------------------------------------------------------------------------




---
Dr. Zisis Papandreou |  email: zisis@uregina.ca
Department of Physics |  tel. : (306) 585-5379
University of Regina |  tel. : (306) 585-4149
Regina, SK  S4S 0A2 |  fax. : (306) 585-5659
World Wide Web:    http://www.phys.uregina.ca/sparro/zisis/