Measurements and calculations of the Coulomb cross section for the production of direct electron pairs by energetic heavy nuclei in nuclear track emulsion. Final report

Technical Report · Tue Nov 01 04:00:00 EST 1988

OSTI ID:6401717

Derrickson, J H; Eby, P B; Fountain, W F; Parnell, T A; Dong, B L; Gregory, J C; Takahashi, Y; King, D T

Measurements and theoretical predictions of the Coulomb cross section for the production of direct electron pairs by heavy ions in emulsion have been performed. Nuclear track emulsions were exposed to the 1.8 GeV/amu Fe-56 beam at the Lawrence Berkeley Laboratory bevalac and to the 60 and 200 GeV/amu O-16 and the 200 GeV/amu S-32 beam at the European Center for Nuclear Research Super Proton Synchrotron modified to accelerate heavy ions. The calculations combine the Weizsacker-Williams virtual quanta method applicable to the low-energy transfers and the Kelner-Kotov relativistic treatment for the high-energy transfers. Comparison of the measured total electron pair yield, the energy transfer distribution, and the emission angle distribution with theoretical predictions revealed a discrepancy in the frequency of occurrence of the low-energy pairs (less than or = 10 MeV). The microscope scanning criteria used to identify the direct electron pairs is described and efforts to improve the calculation of the cross section for pair production are also discussed.

• Research Organization: National Aeronautics and Space Administration, Huntsville, AL (USA). George C. Marshall Space Flight Center
• OSTI ID: 6401717
• Report Number(s): N-89-15692; NASA-TM-100347; NAS-1.15:100347
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BEAMS
BUBBLE CHAMBERS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DOCUMENT TYPES
ELECTRODYNAMICS
ELECTRON PAIRS
EXPERIMENTAL DATA
FIELD THEORIES
GAS TRACK DETECTORS
HEAVY ION REACTIONS
HEAVY NUCLEI
INFORMATION
INTERACTIONS
ION BEAMS
IRON 56 REACTIONS
MEASURING INSTRUMENTS
NUCLEAR EMULSIONS
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
OXYGEN 16 REACTIONS
PAIR PRODUCTION
PARTICLE INTERACTIONS
PARTICLE TRACKS
PROGRESS REPORT
QUANTUM ELECTRODYNAMICS
QUANTUM FIELD THEORY
RADIATION DETECTORS
SULFUR 32 REACTIONS