[BLAST_TOF] tof efficiency

From: Tancredi Botto (tancredi@mitlns.mit.edu)
Date: Thu Sep 05 2002 - 11:33:58 EDT


Well, thanks for updating the shift schedule.. (!)

A few things come to my mind. It may still be a partial list but I hope
it can help (especially those of you that haven't been in the counting
bay recently):

_ Adrian, could you please double check that you have the 40 cm
  extended target in your montecarlo ? When we looked at your results
  for ep of last month (before you left) it seemed that this was not the
  case ! (ask jason ?)

_ The geometrical effect discussed by john is most important for
  field on runs, such as the fresh data from this weekend. You will
  measure with field off so it requires another simulation.

_ Please see chi's note. You will only enjoy benefits by using available
  "standard" code.. It's a good excuse to learn and catch up. Don't forget
  we all expect to be able to redo the same analysis

_ Running with field off you definitely need the slits in (I'll leave
  a note in the counting bay). The proton cut on singles is a bit
  problematic here..
  May I suggest that you use proton_adc_sum>3000 but it won't be too clean

_ Then maybe is better to require rear_paddle && front Cerenkov if singles
  don't work out.

_ You should use (for consistency) available triggers in commis/trig

   r12-15_l12-15_singles_lowt_withcer.settings
   r12-15_l12-15_singles_withcer.settings
   r12-15_l12-15_singles.settings
   r12-15_l12-15_singles_lowt.settings
  
  which have available best timings. note: "_lowt" means that the
  threshold of the first 5 channels has been lowered to 20 mV

_ We have checked the effect of field on/off on all pmt's. There was no
  change (this was done with cosmics)

_ How to gain match the rear paddles is a bit of an issue, hopefully
  ring-related background events (field off only) are all MIP's (ask for
  back-C?)

_ You have to run with the trigger in nonCS mode. I'll have set it up
  for you. Ask karen if in doubt.

*** RETIMING ***

_ Do not forget to delay an additional 16 ns the start counter signal,
  wherever you plug it in. This is best done with a delay unit (else you
  start confusing yourself with the prog. delays)

_ When you are "retiming" - say - the L sector, don't forget to take runs
  with a start counter in R16 *and* L16. For an easier analysis the start
  counter has to be connected always to the same channel, else you need to
  account for the different channel offsets

_ As you know, the start counter connect to right-sector NC channel 0

_ You'll find the macro you need in ~/commis/phase1/retime. There is no
  need to change or write a new macro.

I am very picky about having too many macros written. It is exactly my job
to avoid this from happening...

Good luck !

- tancredi

________________________________________________________________________________
Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124
research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

On Wed, 4 Sep 2002, Adrian T Sindile wrote:

> Pete, Tavi and I discussed and we came up with the following schedule,
> which pretty much covers everything up to Tuesday, except day shifts when
> Doug said he will most likely need the hall open:
>
> Wed Th F Sat Sun Mon
>
> 0-8 TF TF
>
> 8-16 - - - - - TF
>
> 16-24 AS AS PK PK AS AS
>
>
> I will also be with Pete on Friday evening for a few hours and Tavi will
> come a little earlier on Thursday night in order to overlap and make sure
> we all follow the same ideas...
> Thanks!
>
> Adrian
>
> -------------------------------
> Adrian Sindile
> Research Assistant
> Nuclear Physics Group
> University of New Hampshire
> phone: (603)862-1691
> FAX: (603)862-2998
> email: asindile@alberti.unh.edu
> http://einstein.unh.edu/~adrian/
>
>
>



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