Sub-barrier reactions measured using a recoil mass separator

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6783369

Betts, R R

Few data exist in the sub-barrier region for reaction channels other than fusion. In particular, our experimental knowledge of quasi-elastic transfer reactions is sparse, despite the belief that this particular channel may be dominant in determining some features of the sub-barrier fusion enhancement. Transfer reactions are governed primarily by the closet approach of the colliding nuclei which, at low energies, results in a strong backward peaking of the angular distribution in the center-of-mass frame. For situations where the projectile has a significant fraction of the target mass, as is so in most cases of interest, the backscattered projectile-like fragment has such low energy that the usual techniques of measurement and identification become invalid. Here, we report on a solution to this problem which allows a systematic study of many aspects of transfer reactions in the energy regime of interest. We exploit the fact that associated with the low-energy backscattered projectile-like fragment is a complementary target-like fragment which recoils to forward angles with a large fraction of the incident beam energy. These target-like fragments were detected and identified using the Daresbury Recoil Mass Separator thus allowing the measurement of quasi-elastic transfer over hitherto inaccessible energy range from the vicinity of the barrier to several tens of MeV below. The experiments described here used VYNi beams of energies ranging from 180 to 260 MeV provided by the Daresbury Laboratory Nuclear Structure Facility tandem accelerator. Data on sub-barrier transfer for targets of /sup 116,118,120,122,124/Sn and /sup 144,148,150,152,154/Sm were obtained. 16 refs., 10 figs., 2 tabs.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6783369
• Report Number(s): CONF-8806167-6; ON: DE89005803
• Country of Publication: United States
• Language: English

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A=90-149
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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BORN APPROXIMATION
CALCULATION METHODS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DIRECT REACTIONS
DWBA
EXPERIMENTAL DATA
HEAVY ION REACTIONS
INFORMATION
IONIZATION CHAMBERS
ISOTOPES
MEASURING INSTRUMENTS
NICKEL 58 REACTIONS
NUCLEAR REACTIONS
NUMERICAL DATA
RADIATION DETECTORS
RARE EARTH ISOTOPES
SAMARIUM ISOTOPES
THEORETICAL DATA
TIN ISOTOPES
TRANSFER REACTIONS