Observation of p-wave capture strength in the [sup 2]H([rvec d], [gamma]) [sup 4]He reaction at E[sub d] = 80-0 keV

Thesis/Dissertation · Tue Dec 31 23:00:00 EST 1991

OSTI ID:6972295

Kramer, L H

The [sup 2]H(d,[gamma])[sup 4]He reaction is expected to be dominated by electric quadrupole (E2) s-wave ([ell] = 0) capture to the D-state ([ell] = 2) of [sup 4]He below E[sub d] (lab) = 500 keV, where the centrifugal barrier should suppress the electric quadrupole (E2) d-wave ([ell] = 2) capture to the S-state ([ell] = 0). Enhancement of the total cross section below E[sub d] (lab) = 500 keV has been attributed to this mechanism, although no direct evidence exists to support this claim. To investigate this issue, the author has measured the vector and tensor analyzing powers of the [sup 2]H(d,[gamma])[sup 4]He reaction using an 80 keV beam of polarized deuterons. Results are presented for the vector and tensor analyzing powers A[sub y]([theta]) and A[sub yy]([theta]) and the differential cross section [sigma]([theta])/A[sub 0] for E[sub d](lab) = 80 - 0 keV at [theta][sub c.m.] = 0[degrees], 45[degrees], and 82[degrees]. A model-independent transition matrix element analysis of the data finds that a major portion of the capture strength results from electric dipole (E1) and magnetic quadrupole (M2) p-wave capture ([ell] = 1). The data are also compared to a recent microscopic coupled-channel resonating group model calculation which includes electric quadrupole (E2), electric dipole (E1), magnetic quadrupole (M2), and magnetic dipole (M1) transitions and the coupled deuteron-deuteron, proton-triton, and neutron-[sup 3]He channels. The model produces fair agreement with the experimental data when a semi-realistic force is used.

• Research Organization: Duke Univ., Durham, NC (United States)
• OSTI ID: 6972295
• Country of Publication: United States
• Language: English

Related Subjects

663220* -- Electromagnetic Transitions-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA REACTIONS
ANALYZING POWER
BEAMS
CAPTURE
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
D STATES
DEUTERON BEAMS
DEUTERON REACTIONS
DIFFERENTIAL CROSS SECTIONS
E1-TRANSITIONS
E2-TRANSITIONS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
ION BEAMS
M2-TRANSITIONS
MULTIPOLE TRANSITIONS
NUCLEAR REACTIONS
P WAVES
PARTIAL WAVES