Author/Authors :
Rakers، نويسنده , , S and Ellinghaus، نويسنده , , F and Bassini، نويسنده , , R and Bنumer، نويسنده , , C and van den Berg، نويسنده , , A.M and Frekers، نويسنده , , D and De Frenne، نويسنده , , D and Hagemann، نويسنده , , M and Hannen، نويسنده , , V.M and Harakeh، نويسنده , , M.N and Hartig، نويسنده , , M and Henderson، نويسنده , , R and Heyse، نويسنده , , J and de Huu، نويسنده , , M.A. and Jacobs، نويسنده , , E and Mielke، نويسنده , , M and Sch، نويسنده ,
Abstract :
At intermediate energies, the (d,2He) charge-exchange reaction can be used to observe Gamow–Teller strength in the β+ direction. 2He denotes the two-proton system being in the singlet 1S0 state. In the present experiment the two protons, which in the laboratory frame are emitted into the forward direction, have been momentum analyzed and detected in coincidence by the same spectrometer and detector. Protons from deuteron breakup processes can induce a large accidental coincidence background because of the much larger breakup cross-section as compared to the (d,2He) cross-section. Nevertheless, background-free 2He spectra with a resolution of 145 keV at an incident energy of 170 MeV are obtained, allowing the identification of many levels with high precision in the residual nuclei. The essential features of the detection system and the data-acquisition and analysis techniques which make our (d,2He) experiments possible are described. Two nuclei, 12C and 24Mg, have been used as a test case.
