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  • Murad Sarsour (software, detector integration)
  • Xiaochun He (detector integration)



The mRICH is designed for providing PID capabilities for EIC experiments for kaon and pion separation in momentum coverage between 3 to 10 GeV/c and electron and pion separation below 2 GeV/c. See a one-page mRICH below:

One-page mRICH Intro

The mRICH-array design is based on the dimensions listed at , where z=-145 cm and fitting in a radius of 100 cm.

The general design is a wall centered at z=-155 cm (note that the distance between the face of mRICH module and its center (x,y,z)=(0,0,0) is 10 cm) and each module is projected towards IR (0,0,0) while keeping all modules at z=-155 cm. The modules are stacked in rings around the beam pipe as close to each other as possible; however, each ring of modules around the beam pipe are spaced equally. The following are general information:

  • 108 modules are needed to fill 100 cm radius.
  • Module dimension: (x,y,z)=(137.35x137.35x250) mm^3
  • For now the module frame is 1 mm carbon fiber – The general idea (being worked with external engineers) is to have a carbon-fiber honey cone frame for all modules.
  • In the current design, the modules are brought to each other as close as possible beyond the 1 mm frame for each module
  • Each module is projected to (0,0,0) IR.


(in preparation)


  • wall located at z = -145 cm, fitting in a radius of 100 cm
  • pseudorapidity coverage: -3.3 < eta < -1.2
  • total area: ~ 2.1 m^2
  • composed of 108 modules
  • module dimensions: 137.35 x 137.35 x 250 mm^3
  • module contains: carbon fiber frame, Foam holder, aerogel, Fresnel lens, mirrors, and photodetectors.
  • module will be filled with: air
  • aerogel dimension: (x,y,z) = (126.5x126.5x30.) mm^3
  • aerogel location: 83.25 mm from the centre of the module
  • aerogel n-index: 1.03 (at 420 nm)
  • lens dimensions: (x,y) = (133.35x133.35) mm^2
  • lens location: 64.1 mm from the centre of the module with 3.1 mm the gap between the lens and the aerogel
  • photodetector: SiPM / LAPPD / else ?
  • photodetector dimensions: Four matrices at (48.5x48.5x1.5) mm^3 behind a (10.36x10.36) mm^2 glass window
  • photodetector location: 73.57 mm after the lens
  • photodetector segmentation: 3mmx3mm pixel pitch
  • number of channels: 4 matrices with 256 channels per matrix
  • on-board electronics ?
  • on-board high-voltage ?


  • module frame: 1 mm carbon fibre (could be carbon fibre honeycomb)
  • aerogel density:
  • lens material: acrylic
  • lens density:
  • photodetector(s): SiPM matrices / MCP-PMT / LAPPD (?)


The service info listed here is based on the knowledge gained from the past three mRICH-related beam tests at Fermilab. The first mRICH prototype test was performed in 2016 which demonstrated its working principle (results have been published in NIM). The second test was occurred in 2018 with improved mRICH prototype design and smaller pixel size of the photosensors (3mm x 3mm, Hamamatsu H13700 and SiPM matrices). In the second test, a liquid cooling was used for the SiPM sensors (total of three) with temperature settings at -30, -20, -10, 0 and room temperature in celsius. The third test, recently at Fermilab in 2021, was aimed to use LAPPD as an alternative photosensor for mRICH. Further test of LAPPD performance will be needed.

  • high-voltage cables for LAPPD: 2 cables per module
  • bias-voltage cables for SiPM: ~60 volts
  • signal cables: optical link to the frontend readout PCB (directly attached to the sensors with readout chip and FPGAs)
  • cooling: liquid cooling may be needed for SiPM sensors.