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Re: Minutes posted, calib goals requested
Dear all,
that is basically what we are trying to do.Use uniform light to illuminate
many detectors at the same time (or not).The existence of a attenuator for
linerity checking has also to be taken into account.We are experimenting
with the distributor,sources etc
The real questions though are:wavelength of the output of the calorimeter
(fibers,pb-glass) ,approximate light output expected-so to calibrate with
a comperable source.We would like also to know if the FCAL wants to check
the crystals themseleves ,which would mean a radiactive source scan.
Cheers,Christine
> Hi All,
>
> This sounds very similar to what PrimEx used to monitor the gains
> for our calorimeter. Only we used a large LED bundle with an integrating
> sphere. Same rotating wheel idea though.
>
> Regards,
> -David
>
> Alexander Somov wrote:
>> Dear all,
>>
>> I recall at FOPI, GSI, we had a LED trigger to monitor
>> TOF pmt's performance. The light from LED (as far as I remember
>> it was led) was sent to a rotating wheel which had different
>> attenuation steps and was subsequently splitted and distributed to TOF
>> plastic paddles.
>>
>> The trigger ran quite often (mainly in the beginning of data taking, as
>> far as I remember), to monitor linearity/stability.
>>
>> Cheers,
>> Sascha
>>
>> P.S. I will check what we had to monitor ECAL pmt's at Hera-B
>> (there was a monitoring system as well).
>>
>>
>>
>> On Mon, 21 Apr 2008, Elke-Caroline Aschenauer wrote:
>>
>>
>>> On Mon, 21 Apr 2008, Elton Smith wrote:
>>>
>>> Dear all,
>>>
>>> just to give a suggestion it would be very important to vary the light
>>> intensity to test and monitor the linearity of the system.
>>> In hermes we had a system stepping through 5 different light
>>> intensities.
>>>
>>> cheers elke
>>>
>>>
>>>
>>>> Date: Mon, 21 Apr 2008 12:14:54 -0400 (EDT)
>>>> From: Elton Smith <elton@jlab.org>
>>>> To: halld-cal@jlab.org
>>>> Subject: Minutes posted, calib goals requested
>>>>
>>>>
>>>> HI all,
>>>>
>>>> Zisis posted the minutes of today's meeting on the wiki. Thanks! I did
>>>> add
>>>> some comments at the end on questions of calibration.
>>>>
>>>> We need to clearly identify the goals of the calibration system, so
>>>> that
>>>> we build what we need. At the moment, the calibration system is geared
>>>> toward gain monitoring of pmts. For the next meeting, we would like
>>>> the
>>>> Fcal and Bcal and other pmt-based systems to specify what needs to be
>>>> monitored at to what accuracy. Pavlos suggested that it would also be
>>>> useful to give an estimate of the signal size (e.g. number of
>>>> photoelectrons) as well as wavelength response of the detector.
>>>>
>>>> Cheers, Elton.
>>>>
>>>>
>>>>
>>>> Elton Smith
>>>> Jefferson Lab MS 12H5
>>>> 12000 Jefferson Ave
>>>> Suite # 16
>>>> Newport News, VA 23606
>>>> elton@jlab.org
>>>> (757) 269-7625
>>>> (757) 269-6331 fax
>>>>
>>>>
>>> ( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
>>> ) `\ -
>>> / '. | +
>>> | `, Elke-Caroline Aschenauer =
>>> \,_ `-/ -
>>> ,&&&&&V Jefferson Lab +
>>> ,&&&&&&&&: HALL-D 12C / F381 121-A Atlantic Avenue =
>>> ,&&&&&&&&&&; Suite 8 Hampton, VA 23664 -
>>> | |&&&&&&&;\ 12000 Jefferson Ave +
>>> | | :_) _ Newport News, VA 23606 Tel.: 001-757-224-1216 =
>>> | | ;--' | Mail: elke@jlab.org Mobil: 001-757-256-5224 -
>>> '--' `-.--. | +
>>> \_ | |---' Tel.: 001-757-269-5352 =
>>> `-._\__/ Fax.: 001-757-269-6331
>>> -
>>> +=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+
>>>
>>>
>
> --
>
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> David Lawrence Ph.D.
> Staff Scientist Office: (757)269-5567 [[[ [ [ [
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