R&D on high momentum particle identification with a pressurized Cherenkov radiator

A G Agócs ,K Das,G De Cataldo,M.E Patino,E Nappi,I Sgura,G Hamar,L Xaplanteris,A Di Mauro,K Cossyleon,F Piuz,E Futó,D Di Bari,L Das-Bose,J B Van Beelen ,L Molnár ,L Oláh,C Markert,R Bellwied,P Martinengo,G.g Barnafo ̈Ldi ,A R Timmins ,P Lévai,J Yi,L Pinsky,G Volpe,D Das,T Sinha,R T Jimenez ,A Harton,G Bencze,V Peskov,D Varga,Sandun Jayarathna ,G Bencédi,J Song,D Berényi,G Paić,C Pastore,D D Chinellato ,F Cindolo,S Pochybová,L Boldizsár,A G Knospe ,E García-Solis ,J.S Kim,Martin Weber ,S Chattopadhyay,D.W Kim,D B Piyarathna ,F Barile,I K Yoo

doi:10.1016/j.nima.2014.04.019

Abstract

We report on the R&D results for a Very High Momentum Particle Identification (VHMPID) detector, which was proposed to extend the charged hadron track-by-track identification in the momentum range from 5 to 25GeV/c in the ALICE experiment at CERN. It is a RICH detector with focusing geometry using pressurized perfluorobutane (C4F8O) as a Cherenkov radiator. A MWPC with a CsI photocathode was investigated as the baseline option for the photon detector. The results of beam tests performed on RICH prototypes using both liquid C6F14 radiator (in proximity focusing geometry for reference measurements) and pressurized C4F8O gaseous radiator will be shown in this paper. In addition, we present studies of a CsI based gaseous photon detector equipped with a MWPC having an adjustable anode–cathode gap, aiming at the optimization of the chamber layout and performance in the detection of single photoelectrons.

Highlights

We report on the R&D results for a Very High Momentum Particle Identification (VHMPID) detector, which was proposed to extend the charged hadron track-by-track identification in the momentum range from 5 to 25 GeV/c in the ALICE experiment at CERN
The results of beam tests performed on Ring Imaging Cherenkov (RICH) prototypes using both liquid C6F14 radiator and pressurized C4F8O gaseous radiator will be shown in this paper
To significantly enhance the particle identification capabilities in this regime by track-by-track measurements, we have investigated the construction of a new detector, the Very High Momentum Particle Identification Detector (VHMPID)

Summary

Particle identification at high momenta in heavy-ion collisions

QGP as a thermal source or parton fragmentation, can be explored by exploiting various particle identification methods. The separation of pions, kaons and protons at low momenta (p o 3–5 GeV=c) in heavy-ion collisions is for example done with the measurement of the specific energy loss in tracking detectors like a Time Projection Chamber (TPC) or a time-of-flight measurement. The ALICE collaboration presented measurements of identified particles exploiting the relativistic rise region of the specific energy loss in the TPC (dE=dx) [10]. In this method the particle identification is done on a statistical basis, and not trackby-track. The total height adds up to 70 cm, whereof 50 cm is used for the radiator gas and yields in very low material budget with a total radiation length of 22% (see Table 1)

Optimization of the photon detector

Pressurized radiator gas

Summary