arXiv subjects

W. Roh

Publications and source records attributed to W. Roh.

2 recordsLinked to original sources

arXiv2019

Results from a Prototype Combination TPC Cherenkov Detector with GEM Readout

A combination Time Projection Chamber-Cherenkov prototype detector has been developed as part of the Detector R&D Program for a future Electron Ion Collider. The prototype was tested at the Fermilab test beam facility to provide a proof of principle to demonstrate that the detector is able to measure particle tracks and provide particle identification information within a common detector volume. The TPC portion consists of a 10x10x10cm3 field cage, which delivers charge from tracks to a 10x10cm2 quadruple GEM readout. Tracks are reconstructed by interpolating the hit position of clusters on an array of 2x10mm2 zigzag pads The Cherenkov component consists of a 10x10cm2 readout plane segmented into 3x3 square pads, also coupled to a quadruple GEM. As tracks pass though the drift volume of the TPC, the generated Cherenkov light is able to escape through sparsely arranged wires making up one side of the field cage, facing the CsI photocathode of the Cherenkov detector. The Cherenkov detector is thus operated in a windowless, proximity focused configuration for high efficiency. Pure CF4 is used as the working gas for both detector components, mainly due to its transparency into the deep UV, as well as its high N0. Results from the beam test, as well as results on its particle id capabilities will be discussed.

physics.ins-det↗

arXiv2016

Performance of a Quintuple-GEM Based RICH Detector Prototype

Cerenkov technology is often the optimal choice for particle identification in high energy particle collision applications. Typically, the most challenging regime is at high pseudorapidity (forward) where particle identification must perform well at high high laboratory momenta. For the upcoming Electron Ion Collider (EIC), the physics goals require hadron ($π$, K, p) identification up to $\sim$~50 GeV/c. In this region Cerenkov Ring-Imaging is the most viable solution.\newline The speed of light in a radiator medium is inversely proportional to the refractive index. Hence, for PID reaching out to high momenta a small index of refraction is required. Unfortunately, the lowest indices of refraction also result in the lowest light yield ($\frac{dN_γ}{dx} \propto \sin^2{\left(θ_C \right)}$) driving up the radiator length and thereby the overall detector cost. In this paper we report on a successful test of a compact RICH detector (1 meter radiator) capable of delivering in excess of 10 photoelectrons per ring with a low index radiator gas ($CF_4$). The detector concept is a natural extension of the PHENIX HBD detector achieved by adding focusing capability at low wavelength and adequate gain for high efficiency detection of single-electron induced avalanches. Our results indicate that this technology is indeed a viable choice in the forward direction of the EIC. The setup and results are described within.

physics.ins-det↗