sPHENIX tracking discussion

["Frawley, Anthony" <afrawley AT fsu.edu>]

Hi All,

Here are the minutes from today's tracking meeting. Please also note the emails on this thread between Takao and Carlos after the meeting.

The slides are at:

https://indico.bnl.gov/conferenceDisplay.py?confId=1695

Cheers

Tony

Tom Hemmick  - Updates on TPC progress:
-----------------------------------------------------------
Tom showed results of brand new (i.e. very preliminary) field distortion calculations and some initial HV tests on samples of the proposed field cage material.

Slide 7 (see also slide 11).: The primary ionization is V shaped due to the drift to large Z, but the ion backflow smooths out the charge distribution.

I lost my Bluejeans connection partway through Tom's talk, so may have missed some discussion.

Itaru Nakagawa - sPHENIX silicon tracker update:
-----------------------------------------------------------------
Itaru summarized the status of the silicon sensor prototypes and the HDI card pre-production prototype.

Ed: The HDI for FVTX was challenging due to the small spacing between traces, right?
Itaru: Yes, but the FVTX pitch was 40 microns, while our design has 60 microns pitch - not so cutting edge.

Last slide:
The current bid is for design and construction of a pre-production version of the HDI. Itaru expects the company they are working with on the design to win the bid, which explains the comment that the design is almost completed.
Rachid: We will need to add a diode so we can read the temperature of the board and ladder, after we know the HDI design is working. The temperature readout is not included in the pre-production HDI being bid now.

Expect to know the bid winner for the HDI card in the 1st or 2nd week of February.
HDI card production takes about 2 months - expect delivery in March-April.

Rachid Nouicer - Integration of the silicon pixels into sPHENIX:
----------------------------------------------------------------------------------
Rachid reported on the first steps toward understanding how to integrate the reused PHENIX pixels into sPHENIX.

Rachid said that Richi's drawing shows the tracker envelope as extending 75 cm from the center of beam pipe.
Ed said he believes that the number is actually 80 cm. He will check with Richi.

Slide 7:
The initial radii for the two pixel layers were from Mike McCumber, after he tried laying out the ladders. They should be considered as a starting point only.
This exercise is the one that will find a layout that works with the available ladders.

Rachid: Planning to put the center of the sensor at the nominal radius.

Is the intention to run the extender cards parallel to the beam line in sPHENIX? Rachid: still under discussion. Need to understand what is the maximum length of the extender card that will preserve pixel performance. Then we will have to put the SPIRO boards as close as necessary.

Rachid said if anyone has suggestions to email him.

---

From: tsakagu2007 AT gmail.com <tsakagu2007 AT gmail.com> on behalf of Takao Sakaguchi <takao AT bnl.gov>
Sent: Friday, January 15, 2016 10:07 AM
To: Carlos Perez
Cc: Thomas K Hemmick; Frawley, Anthony; sphenix-tracking-l AT lists.bnl.gov
Subject: Re: [Sphenix-tracking-l] sPHENIX tracking meeting Friday January 15 at 9:00 am ET

 

Hi Carlos,

 Thanks for clarification. What I understand from your

answer and Tom's slides from the last meeting is that

you focused both all the ionization electrons and ions

at z=0, which is good as the starting point.

 I assume that the next step is to distribute the 425

charged particles traversing TPC uniformly in phi-rapidity

space, which case that the IFB contribution may be

more significant.

Takao

On Fri, Jan 15, 2016 at 9:52 AM, Carlos Perez <carlos.perezlara AT stonybrook.edu> wrote:

Hi Takao,

The charge distribution is isotropic in phi. The dependence with eta is driven by the amount of time it takes to drift.

The charge density here is parametrised as

rho = A * (1 - |z|/B - D) / r^2

where:

 A is proportional to Multiplicty and Rate and gas conditions

 B is the drift length

 D is proportional to the percentage of back flow

You can find a more detail explanation in previous slides from Tom to the meeting.

Regards,

***************************

Carlos E. Perez Lara

Stony Brook University

Physics and Astronomy

New York, U.S.A.

***************************

On Jan 15, 2016, at 9:27 AM, Takao Sakaguchi <takao AT bnl.gov> wrote:

Hi Tom and Carlos,

 Very nice results on the space charge distribution!

 I just would like to ask one question on the result.

 In the distributions shown in slides 11 to 14, the caption

says that the multiplicity is 425 and the rate is 50KHz.

When you throw 425 particles in an event, did you

distribute the particles uniformly in phi-rapidity space?

Or, did you fix all the particles in z=0 plane?

Takao

On Fri, Jan 15, 2016 at 8:58 AM, Thomas K Hemmick <hemmick AT skipper.physics.sunysb.edu> wrote:

Let me go first and I will try to be fast...

There *ARE* initail space charge calculations.

They are about an hour old, so we need them to mature, but nonetheless, I want to credit all the hard work Carlos put in.

I will be on the line in about 4 minutes...

On Fri, Jan 15, 2016 at 8:54 AM, Frawley, Anthony <afrawley AT fsu.edu> wrote:

Would you like to go first, or later? We have three talks including yours, but the others may be shorter.

Thanks

Tony

---

From: tkhemmick AT gmail.com <tkhemmick AT gmail.com> on behalf of Thomas K Hemmick <hemmick AT skipper.physics.sunysb.edu>
Sent: Friday, January 15, 2016 8:52 AM
To: Frawley, Anthony; Carlos Perez
Cc: sphenix-tracking-l AT lists.bnl.gov
Subject: Re: [Sphenix-tracking-l] sPHENIX tracking meeting Friday January 15 at 9:00 am ET

 

Hi guys

Both Carlos and I have some conflicts regarding the meeting (Carlos VISA business at 9:30, Tom interview with candidate for a physics dept hire).  

We'll try to work around them and make a smooth presentation.

Tom

On Thu, Jan 14, 2016 at 2:14 PM, Frawley, Anthony <afrawley AT fsu.edu> wrote:

Hi All,

Here is an updated agenda for tomorrow morning's tracking meeting:

Tom Hemmick - TPC progress

Itaru Nakagawa - silicon strip tracker progress

Rachid Nouicer - Integration of the silicon pixels into sPHENIX

Tony

---

From: Frawley, Anthony
Sent: Thursday, January 14, 2016 11:07 AM
To: sphenix-tracking-l AT lists.bnl.gov
Cc: Frawley, Anthony
Subject: sPHENIX tracking meeting Friday January 15 at 9:00 am ET

 

HI All,

We will have an sPHENIX tracking meeting tomorow, January 15, at 9:00 am ET. The agenda is at:

https://indico.bnl.gov/conferenceDisplay.py?confId=1695

We will have a report from Tom Hemmick on TPC progress, and one from Itaru Nakagawa on silicon strip tracker progress.

Talk to you then

Tony

-----------------------

The connection details are:

To join the Meeting:
https://bluejeans.com/822435626

To join via Browser:
https://bluejeans.com/822435626/browser

To join with Lync:
https://bluejeans.com/822435626/lync

To join via Cisco Jabber Video:
https://bluejeans.com/822435626/jabber


To join via Room System:
Video Conferencing System: bjn.vc -or- 199.48.152.152
Meeting ID: 822435626

To join via Phone:
1) Dial:
 +1 408 740 7256
 +1 888 240 2560(US Toll Free)
 +1 408 317 9253(Alternate Number)
 (see all numbers - http://bluejeans.com/numbers)
2) Enter Conference ID: 822435626

_______________________________________________
Sphenix-tracking-l mailing list
Sphenix-tracking-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/sphenix-tracking-l

_______________________________________________
Sphenix-tracking-l mailing list
Sphenix-tracking-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/sphenix-tracking-l

--

Takao Sakaguchi
Brookhaven National Laboratory
Physics Department, Bldg. 510C
takao AT bnl.gov
Office: 1-631-344-3345

--

Takao Sakaguchi
Brookhaven National Laboratory
Physics Department, Bldg. 510C
takao AT bnl.gov
Office: 1-631-344-3345