sPHENIX Event Plane Detector discussion

[Ron Belmont <belmonrj AT gmail.com>]

Hi All,

Here are some brief minutes from yesterday’s meeting.  Feel free to send any comments, corrections, etc.

Regards,

Ron

MECHANICAL

Six super sectors have been assembled and moved to 1008, Micah and JaeBeom will do the light-tight testing on them on Thursday.  The north side bike rack is in the back room of 1008 on a wheeled cart and can be rolled into the IR when ready, once there it will need to be lifted into place by crane.  Things are in place for stress relief of the fiber bundles, which can be tied off on the unistrut.  We had a discussion that we want sector zero to correspond to phi = 0 and that the sectors should be labeled carefully prior to installation.

ELECTRONIC

A major open issue is the mounting of the SiPM box and we want to close the loop on this soon.  We may need to bring Russ in because we need some expertise on how to make the appropriate stand off needed for cable clearance.  We brought up the possibility of a dedicated meeting to discuss this particular aspect---when we have pieces from Xometry, assembled, and set up, how do we install it and what fixturing do we need?

For the short Meritec cables, we don't have a delivery date yet but discussed that partial delivery is beneficial - half the order is helpful for box assembly, since we will only build one box at a time.  For the bias power supply form Wiener, the PO is in and the delivery time is 12 weeks from early last week - so we’re looking at roughly end of July for delivery.  Tristan has the PO numbers for both Meritec and Wiener.  Damon has finished the bias supply cables on the box end, which are terminated with a connector.  The other side will be terminated directly at the power rack - that will be done on a maintenance day when tech time will be scarce, so it may take multiple maintenance days to get everything done.

JaeBeom and Dan Lis are going to do some rack tests for the XMIT boards and fibers in the 1008 rack room - the fibers need to be run down to the patch panel.

SOFTWARE

Ejiro showed a very nice demonstration of the EP flattening software.  The material budget in the simulation causes a significant bias in the EP distribution, and the weighting procedure worked perfectly to produce a flat distribution.  We had a rather extended discussion about which quantity should be used for determining the weights.  In the example shown, Ejiro used the tower energy from the simulation.  In real data, we will probably use the calibrated Nmip.  This means there will be two separate steps: first calibrating the Nmip, and then determining the weights from that, rather than determining the weights directly from the raw ADC counts.

-----------------------------------------------------------------------------
Ron Belmont (he/him/his)
RHIC/AGS Users' Executive Committee
Assistant Professor, Department of Physics & Astronomy
University of North Carolina at Greensboro
-----------------------------------------------------------------------------

On Apr 28, 2023, at 6:55 PM, Ron Belmont <belmonrj AT gmail.com> wrote:

Hi All,

We’ll have the next sEPD meeting this coming Tuesday, May 2, at 4pm EDT.

Agenda:

- Project Status

- Mechanical Integration

- Electrical Integration

- Software (online and offline)

Agenda page: https://indico.bnl.gov/event/19375/

Zoom room: https://lehigh.zoom.us/j/99703618048?pwd=djFkNWNCSGk4dHlQRTdObkYwMXhKUT09 

Regards,

Ron

-----------------------------------------------------------------------------
Ron Belmont (he/him/his)
RHIC/AGS Users' Executive Committee
Assistant Professor, Department of Physics & Astronomy
University of North Carolina at Greensboro
-----------------------------------------------------------------------------