Performance studies for a next-generation optical sensor for IceCube-Gen2

Abstract

We present performance studies of a segmented optical module for the IceCube-Gen2 detector. Based on the experience gained in sensor development for the IceCube Upgrade, the new sensor will consist of up to eighteen 4 inch PMTs housed in a transparent pressure vessel, providing homogeneous angular coverage. The use of custom molded optical 'gel pads' around the PMTs enhances the photon capture rate via total internal reflection at the gel-air interface. This contribution presents simulation studies of various sensor, PMT, and gel pad geometries aimed at optimizing the sensitivity of the optical module in the face of confined space and harsh environmental conditions at the South Pole.

A multi-PMT optical sensor for IceCube-Gen2

“…The use of conical gel pads provides photon capture efficiency comparable to metallic reflectors, due to total internal reflection at the surface of the pad (figure 5). This was experimentally verified using a gel pad mounted on a 3 PMT, and counting the number of photons captured when a spot beam is moved across the photocathode area [5]. GEANT4 [6] studies were also performed to optimise the pad shape for greater photon capture efficiency.…”

“…GEANT4 simulations also enabled the comparison of the module effective area and angular acceptance with other optical modules (figure 6). These yielded an increase in Cherenkov spectrumweighted effective area of 3.2-4.2 times for the 16-and 18-PMT LOMs respectively, relative to the IceCube Gen1 DOM, at photon wavelength 400 nm [5].…”