Re: Attenuation length for GEANT

[Matthew Shepherd <mashephe@indiana.edu>]

Hi Beni,

I suggest someone start a page on the Wiki to list all of the pending  
changes needed to calorimetry simulation that are coming about as a  
result of bringing together hardware and simulation aspects of  
calorimetry together to write this document.  (This is great!)

Ones that come to the top of my head now:

- adjust attenuation length in FCAL
- adjust fiber attenuation length in BCAL
- addition of SiPM dark noise to BCAL
- revise threshold in BCAL
- adjust segmentation in BCAL reconstruction

All of these are relatively easy to make but have the serious side  
effects that most of them will throw off the current energy  
calibration and potentially change the resolution of these detectors  
resulting in a variety of reconstruction effects.

-Matt


On Jan 29, 2008, at 1:23 PM, beni zihlmann wrote:

> Hi All,
> looking at comic ray data with F8-00 lead glass and FEU-84-3 pmts I   
> get similar numbers
> as in the note from Richard also around 90cm.
> Currently in the gluex monte-carlo in "hitFCal.c" the attenuation is  
> set to 160cm, however
> it was set to 100cm before but later on modified to 160cm. No idea  
> about when and why
> it happened.
>
> cheers,
> Beni
>
> Richard Jones wrote:
>> Colleagues,
>>
>> To clear up some questions regarding the attenuation length model  
>> in the lead glass that was derived by Radphi, I have posted some  
>> plots and a brief note on the wiki. Please find it at the address  
>> below.  The short answer is that there is no evidence I can find of  
>> a number like 160cm in any of the Radphi records, but that is a  
>> matter of dusty archives at MK and I can sort out.  Meanwhile, the  
>> definitive treatment is described in my note.
>>
>> http://www.jlab.org/Hall-D/software/wiki/index.php/Attenuation_Results_from_Radphi
>>
>> Richard Jones
>>
>> Kornicer, Mihajlo wrote:
>>>
>>> Hi all,
>>>
>>> originally it was 100 cm in the simulation, but I remember number  
>>> like 166cm from Radphi so I chose 160.   I also think Chris  
>>> favored attenuation lenght of ~200cm more than ~100cm for some  
>>> reason, which I do not remember now.
>>>
>>> I hope this helps a little bit.
>>> Mihajlo
>>>
>>>>
>>>> Hi Mihajlo or Richard,
>>>>
>>>> What is the source of the attenuation length choice of 160 cm for  
>>>> the
>>>> FCAL?  We should probably cite this in the simulation document.
>>>>
>>>> Cheers,
>>>>
>>>> Matt
>>>>
>>>
>>>
>>>
>>