[Eg6_analysis] meeting tomorrow

[Nathan Baltzell]

Hi Raphaël,

> Up to now, we never seen any phi dependence of the drift paths,

Sorry, I didn't intend to suggest there should be.  I was just trying
to understand how you can get a global shift from a radial offset
when you average over events that have a symmetric phi distribution.
Take any two regions 180 apart (like the two dominant sectors for
elastics), and if any effect results from a radial offset it should
be opposite sign for them.  But ok, probably I'm thinking wrong ....


> well since we have a phi centered on 180 right now!

The difference between the phis for our elastic electron and alpha
is actually about one/two deg off from 180 on average.  But I was
more interested in knowing if this amounts to truly just a shift
in phi and no effect on curvature, then it is not a big deal and I
should assume no effect on gain calibration.

Regards,
Nathan



On Fri, 08 Mar 2013 09:41:13 -0600, Dupré Raphaël  
<raphael.dupre at gmail.com> wrote:

> Hello Nathan,
>
> Up to now, we never seen any phi dependence of the drift paths,
> Mohammad will have to check this again now that things are working
> better, but I do not expect any variation there.
>
> The shift in phi when moving the beam comes from the fact that most
> event comes from two sectors and are basically produced on the same
> plan. There is no reason that applies while measuring events all over
> the detector, then any shift would affect us.
>
> Yes the shape of dphi gives the curvature, the overall shift is
> apparently due to the shift during the amplification, we could check
> that the value is not crazy there, but it does seem to work pretty
> well since we have a phi centered on 180 right now!
>
> Best,
>
> On Fri, Mar 8, 2013 at 4:03 PM, Nathan Baltzell <baltzell at anl.gov> wrote:
>> Hi Mohammad and Raphaël,
>>
>> It looks like maybe a global shift in dphi of about 1deg.
>> I'm trying to understand, maybe you can help me:
>>
>> Is it correct that the drift paths calibration is independent
>> of phi?  And this would be the same as ageraging over phi.
>> And then is it understood why moving the RTPC would result in
>> a global shift in the dphi calibration for a y-offset but not
>> an x-offset?
>>
>> Is it the case that the shape of this dphi vs TDC distribution is
>> what turns into track curvature, while an overall shift in dphi
>> would just move the track in phi?  Or is that too naive?
>>
>> Sorry if I got this all wrong ....
>>
>> Thanks,
>> Nathan
>>
>>
>>
>>
>>
>> On Fri, 08 Mar 2013 03:33:51 -0600, <hattawy at ipno.in2p3.fr> wrote:
>>
>>> Hello all,
>>>   Following our meeting yesterday, here you can attached file with the
>>> results. New parameters are needed, so i will start directly, i may not
>>> finish today.
>>>
>>> Best regards,
>>> Mohammad.
>>>
>>>
>>>
>>>
>>>
>>>
>>>> Hello everyone,
>>>>
>>>> We will have eg6 meeting tomorrow, March 7, at 10am in F227.
>>>> Agenda can be found at -
>>>>
>>>> http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Meeting_on_March_7_at_10:00am
>>>>
>>>> (thanks to Nathan)
>>>>
>>>> Calling instructions are at -
>>>>
>>>> http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Agendas_and_Minutes_of_the_meetings#Agendas
>>>>
>>>>
>>>> Stepan
>>>> _______________________________________________
>>>> Eg6_analysis mailing list
>>>> Eg6_analysis at jlab.org
>>>> https://mailman.jlab.org/mailman/listinfo/eg6_analysis
>
>
>
> --
> Raphaël Dupré