Speaker
C Ruiz
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
Description
The strength of the 188 keV resonance in the 26gAl(p,g)27Si reaction has been
measured directly in inverse kinematics using the DRAGON recoil separator at
TRIUMF-ISAC. Radioactive 26Al beams with peak intensities of 5 x 10^9 ions/sec were
utilised in conjunction with a windowless, recirculating hydrogen gas target. Recoil
27Si ions were separated and detected with a double-sided silicon strip detector in
coincidence with capture gamma-rays at the target position in a highly efficient BGO
detector array. Background from random coincidence was separated using time-of-flight
through the length of the separator.
Measured silicon charge state distributions using a 28Si beam, combined with stopping
power information measured in the gas target allowed determination of the strength of
this resonance at the level of <20% error. In addition, the resonance energy was
measured via the distribution of gamma-ray hits in the BGO array, leading to the
conclusion that it is lower than previously thought.
The 188 keV resonance dominates the reaction rate at typical Oxygen-Neon Nova
temperatures and the formation of 26Al in Novae depends sensitively on the value of
this rate.
We have found a value of resonance strength differing from the only existing
unpublished measurement that has been used in the reaction networks so far in Nova
nucleosynthesis models.
The results of the experiment will help determine the importance of Novae as
originators of Galactic 26Al compared to other sources, and we discuss the
implications of the measurement in this context.
Primary authors
A Parikh
(Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520-8124, USA)
C Ruiz
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
Co-authors
A. A. Chen
(McMaster University, Hamilton, ON, Canada)
B Davids
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
C Davis
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
C Deibnel
(Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520-8124, USA)
C Jewett
(Dept. of Physics, Colorado School of Mines, Golden, CO 80401, USA)
C Vockenhuber
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
C Wrede
(Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520-8124, USA)
C. V. Ouellette
(McMaster University, Hamilton, ON, Canada)
D Frekers
(Institute fur Kernphysik, Westfalische Willhelms-Universitat Munster, Munster, Germany)
D. F. Ottewell
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
D. H. Hutcheon
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
G Ruprecht
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
H Crawford
(Simon Fraser University, Burnaby, BC V5A 1S6, Canada)
J Caggiano
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
J Clark
(Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520-8124, USA)
J Jose
(IEEEC-UPC, Barcelona, Catalunya, Spain)
J Pearson
(McMaster University, Hamilton, ON, Canada)
J. M. D'Auria
(Simon Fraser University, Burnaby, BC V5A 1S6, Canada)
L Buchmann
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
L Erikson
(Dept. of Physics, Colorado School of Mines, Golden, CO 80401, USA)
L Fogarty
(National University of Ireland, Maynooth, Co. Kildare, Ireland)
M Trinczek
(TRIUMF, Vancouver, BC V6T 2A3, Canada)
P Parker
(Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520-8124, USA)
R Lewis
(Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520-8124, USA)
U Greife
(Dept. of Physics, Colorado School of Mines, Golden, CO 80401, USA)
