Angular distribution coefficients for (γ, X) reactions with linearly polarized photons

Weller, H. R.; Langenbrunner, James R.; Chasteler, R. M.; Tomusiak, E.L.; Asai, J.; Seyler, R.G.; Lehman, D. R.

doi:10.1016/0092-640x(92)90024-c

Cited by 24 publications

(8 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is readily seen from (16) [36] where b denotes j, there is complete agreement between our expressions given by (14) and (15) for a and b and the corresponding expressions in [36]. If it is assumed that E1 s = 0 and…”

supporting

confidence: 60%

“…It is readily seen from ( 16) that the third term c cos θ in (13) arises due to the interference of the M 1 s amplitude with the E1 v amplitudes. This term does not find place in [36], since the calculations there have been carried out separately for the E1 and M 1 transitions. If we identify 2π 2 F IJ ls;1 with 32λ 2 I lsb of [36] where b denotes j, there is complete agreement between our expressions given by ( 14) and ( 15) for a and b and the corresponding expressions in [36].…”

mentioning

confidence: 99%

“…This was followed by measurements at seven γ-ray energies between 2.39 and 4.05 MeV [34]. These measurements with 100% linearly polarized photons have been analyzed, making several simplifying assumptions viz., a) only l = 0, 1 partial waves were considered in the final state due to the low energies involved, b) of the allowed two M 1 and four E1 transitions, the isoscalar E1 leading to 1 P 0 is set to zero, c) the isoscalar M 1 term leading to 3 S 1 is neglected, using the traditional agruments for its supression, d) the three isovector E1 terms were combined to form a single P -wave amplitude, using the theoretical formalism [36], where M 1 and E1 contributions were calculated separately.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Deuteron photodisintegration with polarized photons at astrophysical energies

Ramachandran

Shilpashree

2006

Phys. Rev. C

View full text Add to dashboard Cite

Following precise experimental studies at the Duke Free-Electron Laser Laboratory, we discuss photodisintegration of deuterons with 100% linearly polarized photons using a model independent theoretical approach taking together M 1 and E1 amplitudes simultaneously. The isoscalar M 1s contribution is also taken exactly into account. From the existing experimental measurement on doubly polarized thermal neutron capture, it is seen that the isoscalar M 1s contribution could be of the same order of magnitude as the experimentally measured cross sections at energies relevant to Big Bang Nucleosynthesis (BBN). Therefore appropriate measurements on deuteron photodisintegration are suggested to empirically determine the M 1s contribution at astrophysical energies.

show abstract

supporting

confidence: 60%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Deuteron photodisintegration with polarized photons at astrophysical energies

Ramachandran

Shilpashree

2006

Phys. Rev. C

View full text Add to dashboard Cite

show abstract

“…[7] were then used to obtain the expression for the polarization asymmetry in terms of the three E1 TMEs described above. Letting δ pq = δ p −δ q , we can write the equation for the polarization asymmetry at θ = 90…”

Section: Direct Capture Calculationmentioning

confidence: 99%

“…We limited our analysis to these neutrons because they are the most energetic and most likely to mimic prompt fission neutrons at the lower beam energies. We also used a direct capture model of the time-reversed 8 Be(n,γ) reaction to predict and understand the physical origin of our measured polarization asymmetries in the 9 Be(γ,n 0 ) reaction [7].…”

Section: Introductionmentioning

confidence: 99%

Polarization asymmetries in theBe9(γ,n0)reaction

et al. 2015

View full text Add to dashboard Cite

Measurements of the 9 Be(γ,n 0 ) reaction were performed using nearly 100% linearly polarized, high-intensity, and nearly-monoenergetic γ-ray beams having energies between 5.5 MeV and 15.5MeV at the High Intensity γ-ray Source (HIγS) located at Duke University and Triangle Universities Nuclear Laboratory. Eighteen liquid scintillator detectors were used to measure neutron yields parallel and perpendicular to the plane of beam polarization. Polarization asymmetries, which are the differences between yields observed in detectors located in-plane and out-of-plane divided by their sums, were measured for the neutrons which left the residual nucleus ( 8 Be) in its ground state, termed the n 0 group. Asymmetries between 0.4 to 0.7 were discovered over this energy region in addition to a clear trend of increasing asymmetries with increasing beam energy. A prediction of the polarization asymmetry based on a pure E1 direct capture model shows good agreement with the experimental measurements. These data and the prediction could be of interest for methods that rely on neutron measurements following photofission to identify the presence of special nuclear material.

show abstract