Sphenix-tpc-l mailing list

[Ross Corliss <ross.corliss AT stonybrook.edu>]

Notes from today's meeting are below.  particularly, SOME PEOPLE ARE GIVING PRESENTATIONS ON MONDAY.  They were signed up unilaterally.  Look for your name in the list below or at https://indico.bnl.gov/event/20125/

Upcoming events:

Monday at noon, TPC steering meeting / commissioning schedule etc.

https://indico.bnl.gov/event/20125/

• 12:00 → 12:20
TPC Commissioning Schedule for Run 2023¶
20m
Speaker: Thomas Hemmick (Stony Brook University)

• 12:20 → 12:40
GEM HV Conditioning/Commissioning¶
20m
Speakers: Evgeny Shulga (Stony Brook University), Takao Sakaguchi (BNL)

• 12:40 → 13:00
TPC in Big Partition/TPC-DAQ Interface Issues¶
20m
Speakers: Jin Huang (Brookhaven National Lab), John Kuczewski (BNL)

• 13:00 → 13:20
Diffuse Laser Status¶
20m
Speaker: Charles Hughes (Iowa State University)

• 13:20 → 13:40
Line Laser Status¶
20m
Speaker: Bob Azmoun (Brookhaven National Laboratory)

• 13:40 → 14:00
Operation of Mighty JACK¶
20m
Speaker: John Kuczewski (BNL)

Next laser test is not scheduled yet, will determine on Monday

Next spark test is after July 30, when the cards arrive.

1. Operations overview:

1. Jin and Evgeny are working on a ramp procedure to simplify the TPC power-on.
2. Spark boards arrive July 30, probably install on Aug 2

Diffuse Laser

1. Jin reports that R1 s06 saw some laser load in the GEM HV trace.  Happened between 11072 and 11073.
2. We have to understand the noise pulse that's correlated with the laser pulse

1. it will disrupt tracking, even if it doesn't 
2. Bob: look at other detectors read out in synch
3. Ross: read ground on a scope
4. Test: want one GEM at full voltage, rest at 'standby'

1. R2 near a known B=0 hotspot.
2. can read out 50us of data at a time.

1. this would let us try to see the ground pulse and the laser flash in the same frame.

can see the photoelectron load on the GEM directly, even if not timed in.


If gain issues don't resolve this, we need to consider if the B field may be killing laser QE.

1. Test:  put a Nd magnet on the back of a sample in Bob's QE test.
2. Calc:  Bob will give a stab into mean free path modifications
3. Last test, if needed: step the B field up in small steps, from 10% upward, with Kin's blessing, and monitor laser flash yield.

Line Laser

1. Seth working on Laser GoTo instruction, and calculating the laser path for given inputs
2. Ross will start working with Seth on the dog leg controls
3. Controller board:  old order status probably lost-to-oblivion.  John K. is ordering new controller boards
4. assumign boards arrive in 2 weeks, we expect 4 weeks before any primary alignment
5. Dan shows two changes to the dogleg motors for the next gen:

1. Proposed cutting the top plate to allow the motion to be aligned independently
2. current hub has a brass insert that is epoxied in and threads onto the knob of the kinematic mount.  This would be removed and replaced with a press-fit system in the bearing, with a slip fit used to hold an allen key that drives the spring-loaded axle.  This way the encoder stays at constant distance.

1. concentricity issues may still exist, because we aren't swapping out all the parts.

Also modifying the fitting that connects the egg to the light pipe.

==========
Dr. Ross Corliss
Research Assistant Professor
Center for Frontiers in Nuclear Science
Stony Brook University
virtual office:  https://stonybrook.zoom.us/my/rossoffice?pwd=ZmZ2SlRIMVFvUUJwbUkyOVNVTmE5QT09

On Jul 21, 2023, at 11:09 AM, Ross Corliss <ross.corliss AT stonybrook.edu> wrote:

Hi All,

Can we catch up briefly on TPC issues this afternoon at the usual 2pm time and zoom-place?  

https://bnl.zoomgov.com/j/1619343392?pwd=MDExeG91aHgyYlJrUldadjZSaGdhUT09

Jin has proposed moving the meeting to Thursdays at the same time, to reduce scheduling conflicts, so we can settle that this afternoon.

-Ross

==========
Dr. Ross Corliss
Research Assistant Professor
Center for Frontiers in Nuclear Science
Stony Brook University
virtual office:  https://stonybrook.zoom.us/my/rossoffice?pwd=ZmZ2SlRIMVFvUUJwbUkyOVNVTmE5QT09

On Jul 14, 2023, at 1:46 PM, Ross Corliss <ross.corliss AT stonybrook.edu> wrote:

HI All,

Sorry for the short notice -- Are folks free to meet up per usual, catch up on what the other hand is doing, etc?

https://bnl.zoomgov.com/j/1619343392?pwd=MDExeG91aHgyYlJrUldadjZSaGdhUT09

-Ross

==========
Dr. Ross Corliss
Research Assistant Professor
Center for Frontiers in Nuclear Science
Stony Brook University
virtual office:  https://stonybrook.zoom.us/my/rossoffice?pwd=ZmZ2SlRIMVFvUUJwbUkyOVNVTmE5QT09

On Jun 30, 2023, at 12:58 PM, Ross Corliss <ross.corliss AT stonybrook.edu> wrote:

Hi All,

As previously, if pressing TPC work doesn't override, I think it would be good to have a status check-in at the usual time, 2pm today:

https://bnl.zoomgov.com/j/1619343392?pwd=MDExeG91aHgyYlJrUldadjZSaGdhUT09

-Ross

==========
Dr. Ross Corliss
Research Assistant Professor
Center for Frontiers in Nuclear Science
Stony Brook University
virtual office:  https://stonybrook.zoom.us/my/rossoffice?pwd=ZmZ2SlRIMVFvUUJwbUkyOVNVTmE5QT09

On Jun 16, 2023, at 12:56 PM, Ross Corliss <ross.corliss AT stonybrook.edu> wrote:

Hi folks,

If folks are free, I think it would be good to bring the various TPC teams up to speed on current status, using the TPC operations zoom at the 'usual' time, 2pm today.

https://bnl.zoomgov.com/j/1619343392?pwd=MDExeG91aHgyYlJrUldadjZSaGdhUT09

(If we become a nuisance there, we can fall back to a different zoom link)

As before, feel free to spread the invite to interested parties, or demur if you have other obligations -- I know we're all busy.

-Ross

==========
Dr. Ross Corliss
Research Assistant Professor
Center for Frontiers in Nuclear Science
Stony Brook University
virtual office:  https://stonybrook.zoom.us/my/rossoffice?pwd=ZmZ2SlRIMVFvUUJwbUkyOVNVTmE5QT09