New
Results with
TECSA – the d(26Alm,p)27Al experiment, B. T.
Roeder1, L. Trache1,
T. Davinson2, V. E. Iacob1, M. La Cognata3,
G.
Lotay2, M. McCleskey1, R. G. Pizzone1,3,
G. G.
Rapisarda3,4, E. Simmons1, R. Sparta3,4, A. Spiridon1,
C. Spitaleri3,4,
R. E. Tribble1, and P. J. Woods2, [1] Cyclotron Institute, Texas
A & M
University, College Station, Texas, USA; [2] School of Physics and Astronomy, University of
Edinburgh, Edinburgh EH9
3JZ, United Kingdom ; [3] INFN
Laboratori Nazionali del Sud, 95123 Catania, Italy; [4] Dipartimento di Fisica e
Astronomia,
Università di Catania, 95123 Catania, Italy − The
detection of gamma rays
from the decay of the 26Al ground state in the
galaxy gives evidence
that nucleosynthesis is occurring in present-day stars, but its
origin is not
yet clear. This
implies that reactions
involving 26Al are important for astrophysical
processes. In a
recent experiment at the Cyclotron
Institute at Texas A & M University, reactions with the
ground state and
isomeric state of 26Al were investigated with the Texas A &
M-Edinburgh-Catania
Silicon detector Array (TECSA). TECSA
is
a collaborative effort to build a high-efficiency detector Si
array useful for
measuring reactions of interest for nuclear astrophysics and
nuclear structure.
The array consists
of up to 16 Micron
Semiconductor YY1 detectors that are each 300 um thick. Each detector has 16
annular ring sectors to
measure the energy and the scattering angle of the detected
particles. Using
TECSA, we measured d(26Alg,p)27Al
and d(26Alm,p)27Al with an 26Al
secondary beam
prepared in-flight with the MARS spectrometer. First, the
composition of the 26Al
beam was determined by measuring the ratio of beta-decays to 26Al
ions
produced. It was
found that at
different spectrometer rigidities, beams of 2/3 isomer to ground
state ratio or
vice-versa could be obtained. Then,
in
the second part of the experiment, angular distributions were
measured for both
reactions at backward angles with TECSA. The protons were
measured in TECSA in
coincidence with timing signals from the beam detected by a
scintillator and
with the cyclotron radio-frequency. Details of the
experiment and results from the
analysis of the d(26Alm,p)27Al and d(26Alg,p)27Al
data
will be presented. They
will give
information about the proton capture reactions 26Alm(p,γ)27Si
and
26Alg(p,γ)27Si taking place in stars.