Nuclear Astrophysics with

the Silicon Detector Array (SIDAR)

Precision measurements of nuclear reactions involving unstable nuclei are currently being carried out at ORNL's Holifield Radioactive Ion Beam Facility (HRIBF) to improve our understanding of stellar explosions such as novae and X-ray bursts. Many of the experiments involve a radioactive heavy ion beam incident on a thin foil targets (CH₂ or CD₂), and using arrays of charged particle detectors - sometimes in combination with the Daresbury Recoil Separator - to measure the products of the resultant (p,p), (p,p'), (p,alpha), or (d,p) reactions.

We need to precisely measure the emission angle, energy, arrival time, and elemental composition of the light and heavy products of these inverse kinematics (heavy beam striking a light target) reactions to determine reaction yields, angular distributions, spectroscopic factors, resonance energies, and other quantities required to calculate thermonuclear reaction rates. We are utilizing a large-solid angle, highly-segmented, customizable array of high energy resolution silicon strip detectors in our target chamber. This Silicon Detector Array (SIDAR) , coupled to high-density electronics, has been used for numerous successful experiments with beams of radioactive fluorine isotopes.

A schematic setup of the array is shown in this diagram and detector overview. More technical information on SIDAR can be found in D.W. Bardayan et al., Phys. Rev. C62 (2000) 055804. Some recent results with the SIDAR array are given in an article on our recent accomplishments.

Further Information

Recent Accomplishments in Nuclear Astrophysics with Radioactive Ion Beams at HRIBF

Overview of Experimental Nuclear Astrophysics Research Program at HRIBF

Holifield Radioactive Ion Beam Facility

Daresbury Recoil Separator

DRS Detector Systems