Photon detector for MEGA. [53 MeV]
The MEGA photon detector is designed to observe the 52.83-MeV photon produced in a [mu] [yields] e[gamma] decay with an energy resolution of 1.25 MeV, a position resolution of 2 [times] 5 mm[sup 2], a directional resolution of 10[degree], a time resolution of 500 ps, and an efficiency of about 5.4%. It will consist of three independent concentric cylindrical pair spectrometers mounted within a 1.5 T magnetic field produced by a superconducting solenoid magnet. Each pair spectrometer includes two thin Pb foils to convert photons into e[sup +]e[sup [minus]] pairs. The two smaller pair spectrometers will have three drift chamber layers to track the e[sup +]e[sup [minus]] pairs and thereby determine both their locations and their vector momenta. The third pair spectrometer will have four layers of drift chamber, together with a larger turning region, to provide better tracking information for high energy photons. The inner drift chamber layer in each of the spectrometers includes a delay line cathode to determine the z coordinates needed for track reconstruction. An MWPC located between the two Pb layers identifies the conversion layer so that energy loss corrections may be applied, while plastic scintillators provide timing information. During the past year, efforts have focused primarily on software development, completion of the delay line tests, and development of electronics for the scintillators and delay line read-out. Optical windows were glued onto the light guides required for the third pair spectrometer. In addition, major contributions were made to the development of a proposal to measure the Michel parameter, [rho], using the MEGA positron detectors.
- Research Organization:
- Texas A and M Univ., College Station, TX (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG05-87ER40310
- OSTI ID:
- 6955413
- Report Number(s):
- DOE/ER/40310-T2; ON: DE93004366
- Country of Publication:
- United States
- Language:
- English
Similar Records
Photon detector for MEGA
Photon detector for MEGA. Final report, July 16, 1992--May 31, 1993
Related Subjects
DRIFT CHAMBERS
DELAY CIRCUITS
PHOTONS
DETECTION
DATA ACQUISITION SYSTEMS
MEV RANGE 10-100
MUONS PLUS
PAIR SPECTROMETERS
PERFORMANCE
POSITRONS
PROGRESS REPORT
WEAK HADRONIC DECAY
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BOSONS
DECAY
DOCUMENT TYPES
ELECTRONIC CIRCUITS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
GAMMA SPECTROMETERS
LEPTONS
MASSLESS PARTICLES
MATTER
MEASURING INSTRUMENTS
MEV RANGE
MULTIWIRE PROPORTIONAL CHAMBERS
MUONS
PARTICLE DECAY
PROPORTIONAL COUNTERS
RADIATION DETECTORS
SPECTROMETERS
WEAK PARTICLE DECAY
440104* - Radiation Instrumentation- High Energy Physics Instrumentation