[Halld-cal] Draft of BCAL constants document

[semenov at jlab.org]

Elton:

I have a few corrections to the formulas in your document:

Equation 12 on the page 4: In the second term, it should be
"lambda0*exp(-Z/lambda2)" (viz., you missed the "minus" sign for the "Z").

Equation 17 on page 7: In the case of "single-exponent" case, the
"attenuation-to-center-correction" factor should be "exp(L/(2*lambda))"
(not just "exp(L/2)" as you have now). In you'd like to use
"short-long-attenuation" model, the factor should be 1/f(0), where f(0)
comes from eq.12

The g-prime coefficient (on page 7) came from the fitting of the cosmics
ADC spectra to the function I used to describe Irina's simulation results;
if you want some simplification, it will be not a big mistake to say that
it equals to the
simulated-muon-peak-in-att-MeV/measured-muon-peak-in-fADC-integral. (In
reality, I'm trying to fit not just the peak positions together but to
find the best match for whole shapes of simulated-and-scaled and measured
spectra.)

Hope, it helps,
Andrei




> Hi all,
>
> Local JLab: I have booked L207 for both the BCAL reconstruction (11:15)
> meeting and the BCAL calibration constants meeting (2 pm),
>
> I have updated the version of the document on DocDB, mainly correcting
> typos and adding clarifying information and indeed continue to update it
> as I get feedback. If you have any corrections/feedback that do not
> require discussion send them to me and I can update the document
> offline. Before the meeting you may wish to check out the latest version
> for discussion.
>
> Andrei: In order to use your calibration constants correctly, we need to
> know what attenuation length you used to determine the "attenuated
> energy". Could you please send the value.
>
> Thanks, Elton.
>
>
>
> Elton Smith
> Jefferson Lab MS 12H3
> 12000 Jefferson Ave STE 4
> Newport News, VA 23606
> (757) 269-7625
> (757) 269-6331 fax
>
> On 12/11/14 3:48 PM, Elton Smith wrote:
>> Hi Zisis,
>>
>> Ok. I suggest we meet tomorrow afternoon at 2 pm and review the
>> calibration document.
>>
>> Thanks, Elton.
>> Elton Smith
>> Jefferson Lab MS 12H3
>> 12000 Jefferson Ave STE 4
>> Newport News, VA 23606
>> (757) 269-7625
>> (757) 269-6331 fax
>> On 12/11/14 12:41 PM, Zisis Papandreou wrote:
>>> Hi Elton:
>>>
>>> I am available on Friday only between 2-4pm EST.    Monday is wide
>>> open though.
>>>
>>> Cheers, Zisis...
>>>
>>> On Dec 10, 2014, at 1:39 PM, Elton Smith <elton at jlab.org
>>> <mailto:elton at jlab.org>> wrote:
>>>
>>>> Dear colleagues,
>>>>
>>>> I have uploaded a draft document (GlueX-doc-2618) with definitions for
>>>> the low-level calibration constants for the BCAL. This is a document
>>>> for
>>>> discussion and feedback is welcome. The goal, after we have hashed it
>>>> out, is to have precise definitions of all constants that are placed
>>>> in
>>>> the calibrations data base. In particular, it is necessary to choose
>>>> some conventions, which need to be clear to avoid errors in
>>>> reconstruction. We need to agree on what those conventions are. We
>>>> should also make sure that there are no factors of 2 missing.
>>>>
>>>> The document proposes that the gains be specified at the center of the
>>>> module.  If I understand correctly, this is different than Andrei's
>>>> convention that uses the end of the module.
>>>> Therefore, there is a factor of e^{-L/2*lambda} between the two that
>>>> needs to be sorted out. There may also be other definitions or
>>>> conventions that need consensus.
>>>>
>>>> We should probably find a dedicated time to go over this. As we are in
>>>> the process of entering constants into db now, I would hope to have a
>>>> discussion soon. Is Friday a possibility?
>>>>
>>>> Thanks, Elton.
>>>>
>>>>
>>>> --
>>>> Elton Smith
>>>> Jefferson Lab MS 12H3
>>>> 12000 Jefferson Ave STE 4
>>>> Newport News, VA 23606
>>>> (757) 269-7625
>>>> (757) 269-6331 fax
>>>>
>>>> _______________________________________________
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>>>
>>>
>>> Dr. Zisis Papandreou
>>> Professor of Physics, Ph.D., P.Phys.
>>> ---------------------------------------------------------
>>> Department of Physics
>>> University of Regina
>>> 3737 Wascana Parkway
>>> Regina, SK S4S 0A2 CANADA
>>>
>>> *Phone: (306) 585-5379*
>>> Fax: (306) 585-5659
>>> Email: zisis at uregina.ca <mailto:zisis at uregina.ca>
>>> Website:
>>> http://www.uregina.ca/science/physics/faculty-staff/faculty/zisis-papandreou.html
>>> <http://kronos.phys.uregina.ca/%7Ezisis/professional/>
>>>
>>>
>>>
>>>
>>>
>>
>
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