INDIRECT STUDY OF LOW-ENERGY RESONANCES IN (31)P(P,ALPHA)SI-28 AND CL-35(P,ALPHA)S-32

The reaction sequences governing the reaction flow in the rp process a re important for the understanding of the energy generation and nucleo synthesis of heavy elements in hot and explosive stellar hydrogen burn ing. Of considerable interest are (p,alpha) reactions along the proces s path which lead to the formation of reaction cycles rather than to c hains of proton capture processes and beta decays. Previous direct att empts to measure the low-energy reaction cross sections for P-31(p,alp ha)Si-28 and Cl-35(p,alpha)S-32 resulted only in upper limits for the strengths of possible low-energy resonances which may dominate the rea ction rates. In this paper an indirect experimental approach is presen ted to study the structure of the low-energy unbound states in the com pound nuclei S-32 and Ar-36. Th, results allow a more accurate determi nation of the contributions of these low-energy levels in the (p,alpha ) reaction channel.