High pt project at RHIC-PHENIX

What's New

Definition of the project

To enhance the PID capability of PHENIX, we like to install Aerogel Cherenkov counters (160 cells) at W1 Sector on the West Arm of the PHENIX Experiment. We will use Silica Aerogel (SP-12M, made by Matsushita Electric Works, Ltd), which has refractive index of 1.011. Together with RICH (n=1.00041), TOF (100ps) and this Aerogel Cherenkov Counter, we can extend particle identification almost seeminglessly upto 8~9 GeV/c.

T(Introduction in Japanese)

Detector R&D

  • In December 2001, test experiment (T496) for the Aerogel Cherenkov have been carried out at KEK with Dr. Vladimir Ladyguine, Dr. Valeri Peressedov from Dubna. (Photos;part1, part2)
  • Both Belle type (aerogel w. 2 PMT's on the side) and Mirror type (mirror followed by 1 PMT behind the aerogel) have been tested. So far, best results (>20 p.e.) obtained from Belle type with 3" PMT's and Goretex as reflector, which is our backup solution now.
  • Position dependences of both counters are found to be acceptable.
  • More detailed stories can be found here.
  • We will continue R&D and test experiments for both mirror and Belle type. (Next test beam will be before the summer.)
  • For the deltailed analysis of optical properties of the Aerogel, such as wavelength dependences of absorption length & scattering length, study with a laser and spectrometer is also in progress.
  • Comparison of Aerogel from Matsushita and Novosibirsk gives interesting results; while similar results obtained when non-UV PMT was used, Novosibirsk Aerogel provides 20 - 30 % larger signal than that of Matsushita with UV PMT (Quartz window). As is reported in literature, Novosibirsk aerogel seems to have better optical transmission in UV. (According to Sumiyoshi at KEK, master of aerogel, more complicated process is adopted for production of aerogel at Novosibirsk.)

PISA simulation

  • PISA simulation activity has started at Tsukuba. ~300 aerogel counters of Belle type (12 cm x 12 cm x 12 cm) have been installed to the West Arm.
  • Occupancy and background studies have been studied as a first step.

Participation of Dubna Group

  • Y.Miake has visited Dubna in March 10 - 12, 2002. We have agreed to work together for this upgrade project.
  • We will exchange official document of Agreement between JINR-LHE and Inst. of Physics, Univ. of Tsukuba for this upgrade project.
  • Their participation will be detector r&d, mechanical/engineering design of the system, mechanical construction of counters. Details are under discussions.

Issues and concerns

Further Information;

Send comments/requests to miake@tac.tsukuba.ac.jp