A coincident measurement of the three-body photodisintegration of helium-3

This experiment measured coincident neutron-proton pairs from the photodisintegration of 3He. The bremsstrahlung photon beam was produced by a 100 MeV electron beam, supplied by the University of Illinois Nuclear Physics Laboratory 100 % duty factor electron microtron. The energy and angle of the np pairs were used to reconstruct the energy of the photon, making this a kinematically complete experiment. The 3He(gamma ,np )p data were normalized to measured 2H(gamma ,np) yields and published deuterium photodisintegration cross sections. The target was a cryogenic system which maintained the 3He gas at liquid 4He temperature. Protons were detected with a dE-E scintillation telescope and neutrons with a position sensitive scintillation array. The proton energy was determined from the energy deposited in a Nai crystal and the neutron energy from the time of flight over a 4 m path. The neutron and proton were detected on opposite sides of the photon beam at opening angles from 122-202 degrees in the lab frame. Quasi-deuteron breakup events were detected for photon energies of 45-95 MeV. Strong final state interactions prohibited an accurate determination of the quasideuteron contribution to the cross section. The single differential cross section ([greek letters]) for 3He at Theta P = 81° was determined by integrating the neutron angular distribution. This cross section, relative to deuterium, ranged from 2.39±.16 at 55 MeV to 1.67±.27 at 95 MeV.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Kolb, Norman Reed

Contributors dc:contributor

• Smith, J.H.

• coincident neutron proton pairs
• photodisintegration
• Helium-3 (3He)
• bremsstrahlung photon beam

Statement dc:rights

• 1990 Norman Reed Kolb

Language dc:language

en

Identifier

1856825

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25095