[Moller_simulation] MOLLER sim. telecon. extra meeting

[Krishna Kumar]

Hi, Folks. I will not be able to call in on Tuesday since I will be out of town. However, I gather that you will be discussing Peiqing's slides that were posted on the previous meeting page. I will take a detailed look at the results for the thin quartz and perhaps send further comments. However, I wanted to make sure that I immediately communicate our main idea for the "shower max" detector that is to sit behind the  main detector rings:

The idea is to have a sandwich of quartz and tungsten. This is much better than having a single pre-radiator. Piotr Decowski (cc'ed here) did such a study for a potential sandwich detector for PREX. The optimization of the ratio of tungsten thickness to quartz thickness and the number of such layers is the key to the required MC study.  The goal would be to ensure that 3 to 8 GeV particles will have at least 20% resolution. Then the excess noise will be below 2%. I would not worry too much about 1 to 3 GeV particles in this optimization. They are much rarer and have a much lower figure of merit (analyzing power). Hopefully the optimization will show that we need somewhere in the range of 10 to 15 X_0 total thickness and no more. This will reduce the relative pion background by a factor of 3 compared to thin quartz, which is another determining factor in this optimization. If the optimization is relatively flat for a range of thicknesses, then the thinnest solution should be chosen. 

I seem to recall that our simulations showed that one can get about 35%/Sqrt(E) for 7 or 8 layers of alternating 1 mm tungsten and 10 mm of quartz (or maybe it was 5 mm?). Piotr might be able to quickly find a technical note where we did the optimization for PREX. We ultimately decided not to use it because the resolution was far worse than for thin Quartz at 1 GeV. But it will be much better for 3 GeV and up. 

BTW, Piotr should be put into the simulation emails. I am sure he would like to call in when possible.

Cheers, KK

On Nov 15, 2012, at 1:02 PM, Juliette Mammei <crowder at jlab.org> wrote:

> Hey guys,
> 
> Thanks to all who responded to the Doodle poll.  It looks like the best 
> time for the extra meeting is next Tuesday, November 20th at 4pm EST.  
> I'll send an announcement with an agenda by Monday afternoon.
> 
> Talk to you later,
> 
> Juliette
> 
> On 13/11/2012 1:44 PM, Juliette wrote:
>> Hey guys,
>> 
>> The simulation meetings have been taking longer than expected, and we 
>> have had to put agenda items off until the next meeting several times, 
>> including this last time.  Also, there are some special scheduling 
>> issues coming up, including the Qweak collaboration meeting this week 
>> and Thanksgiving.  So, we would like to have an "extra meeting" 
>> between now and our next regularly scheduled meeting time.  I have 
>> created a Doodle poll to set up the time for that meeting:
>> 
>> http://www.doodle.com/mrgmnabip6iisskm
>> 
>> Please fill out times when you can attend this special meeting. Note 
>> that you can choose your time zone in the upper right.  The first 
>> couple times should be tomorrow (Wednesday) at 3pm and 4pm EST, which 
>> are actually not ideal for me.
>> 
>> At this meeting we will also consider having weekly meetings with set 
>> agendas, possibly with "results" one week and discussion about 
>> development in the alternating week.
>> 
>> Talk to you later,
>> 
>> Juliette
>> 
> 
> 
> -- 
> Dr. Juliette Mammei
> 
> Assistant Professor
> Department of Physics and Astronomy
> University of Manitoba
> Winnipeg, Manitoba
> R3T 2N2 Canada
> 
> Office: 1-204-474-6195
> 
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