General EEEMCal Meeting Summary 6/28/21

EEEMCAL MEETING - 28 JUNE 2021

PARTICIPANTS: Alexander Bazilevsky, Bruno Jolion, Carlos Munoz-Camacho, Cristiano Fanelli, Crytur-USA, Douglas Hasell, Hamlet Mkrtchyan, Hrachya Marukyan, Gabriel Niculescu, Julien Bettane, Lei Guo, Miroslav Finger, Nathaly Santiesteban, Petr Stepanov, Renee Fatemi, Richard Milner, Rosi Reed, Vardan Tadevosyan, Tanja Horn

EEEMCAL IN THE DETECTOR PROPOSALS

• Similar configuration in all detector proposals

• differences in distribution of crystals (2 x 2 x 20 cm^3) vs. SciGlass (4 x 4 x 40 cm^3)

• Differences in frame and support design depending if inside or outside DIRC

• Universal ("DIRC") frame - current assumption for Athena and ECCE
• Cantelevered from HCAL - CORE investigating this option

PRE-DESIGN OF EEEMCAL (Julien Bettane)

• Presentations of an analysis for the following cases:

• location: IP-6 (one EMCal) and IP-6+IP-8 (two EMCals)
• configurations: 1.5T/ECCE, 2T/CORE, 3T/ATHENA
• installation location: outside DIRC mounted to endcap HCAL, inside DIRC mounted on barrel HCAL and DIRC

• Main points to pay attention to for the design:

• Maintenance
• Structure
• Cooling

• For maintenance space around the detector is important and also need for accessing the other detectors

• IP-6 only or IP-6+IP-8: No negative effects for the mechanical design
• 1.5T or 2T or 3T: increase the size of the mechanical structure and the cooling (depends on the DIRC configuration)
• EMCAL Outside DIRC: Moving of the EMCAL for maintenance --> Probably 2 parts needed

• For support structure need to consider the impact on the beam pipe - a mechanical structure is needed for the inner radius no matter if the EMCal comes in one or two parts

• there are some advantages to having one part as then have the full circular structure to bear the load - having two parts increases the thickness of the structure needed
• Another consideration: if taking out the detector along the beam pipe this would increase the diameter
• overall, goal is to minimize the clearance between the mechanical structure and the beam pipe

• Inner (between blocks) structure

• Use of a mechanical structure like carbon fiber between blocks could make it easier to assemble the detector - possible to use 3x3 sub-sections (maybe more useful for a large detector, e.g., outside the DIRC)
• Carbon plates can also help with positioning of blocks
• Problem with two-part EMCal: need additional plate for alignment

• Attachment/mounting

• EMCal inside DIRC: mounted on universal frame (solution A)

• alternatively attach to endcap HCAL (solution B), but questions about maintenance mode

• Cooling - 3 possible options (nano-shell, SiPM onboard, traditional)

• planning a prototype test with nano-shell material - heat conductivity 17 kW/m/K

PWO+SIPM DETECTOR UPDATE (CRYTUR/CRYTUR-USA)

• SiPMs with 15um pitch have been purchased - expected to arrive end of July

• Design work ongoing

• Discussion about the requirements for temperature stabilization

• should be stabilized across crystals
• should be able to use back of detector for heat dissipation

• Action item:

• Estimation of power deposition
• Needed information for installation:

• Number of channels: 9x 50 V (1 signal per crystal)
• Length of detector with crystals and photosensors

NEXT MEETING: MONDAY 12 JULY AT 8:30AM ET