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The (96)Mo(d,(2)He)(96)Nb charge-exchange reaction was investigated at an incident energy of E(d)=183.5 MeV. An excitation-energy resolution of 110 keV was achieved. The experiment was performed at KVI, Groningen, using the magnetic spectrometer BBS at three angular positions: 0(degrees),2.5(degrees), and 6(degrees). We found that below 6 MeV almost the entire Gamow-Teller (GT(+)) strength is concentrated in a single state at 0.69 MeV excitation energy. As (96)Mo is the daughter of the beta beta decay nucleus (96)Zr, the present result provides information about the nuclear matrix elements active in the 2 nu beta beta decay of (96)Zr.

The (d,(2)He) charge-exchange reaction on (76)Se was studied at an incident energy of 183 MeV. The outgoing two protons in the (1)S(0) state, referred to as (2)He, were both momentum analyzed and detected by the same spectrometer and detector. The experiment was performed at KVI, Groningen, using the magnetic spectrometer BBS at three angular positions: 0(degrees),2.5(degrees), and 5(degrees). Excitation-energy spectra of the residual nucleus (76)As were obtained with an energy resolution of about 120 keV (FWHM). Gamow-Teller (GT(+)) transition strengths were extracted up to 5 MeV and compared with those from an (n,p) experiment at low resolution. Together with the GT(-) transition strengths from the (76)Ge(p,n) experiment leading to the same intermediate nucleus, the nuclear matrix element of the two-neutrino double-beta decay of (76)Ge was evaluated.

The (d,(2)He) charge-exchange reaction on (76)Se was studied at an incident energy of 183 MeV. The outgoing two protons in the (1)S(0) state, referred to as (2)He, were both momentum analyzed and detected by the same spectrometer and detector. The experiment was performed at KVI, Groningen, using the magnetic spectrometer BBS at three angular positions: 0(degrees),2.5(degrees), and 5(degrees). Excitation-energy spectra of the residual nucleus (76)As were obtained with an energy resolution of about 120 keV (FWHM). Gamow-Teller (GT(+)) transition strengths were extracted up to 5 MeV and compared with those from an (n,p) experiment at low resolution. Together with the GT(-) transition strengths from the (76)Ge(p,n) experiment leading to the same intermediate nucleus, the nuclear matrix element of the two-neutrino double-beta decay of (76)Ge was evaluated.

The Ni-64(d,He-2)Co-64 reaction was studied at the AGOR cyclotron of KVI, Groningen, with the Big-Bite Spectrometer and the EuroSuperNova detector using a 171-MeV deuteron beam. An energy resolution of about 110 keV was achieved. In addition to the J(pi) = 1(+) ground state, several other 1(+) states could be identified in Co-64 and the strengths of the corresponding Gamow-Teller transitions were determined. The obtained strength distribution was compared with theoretical predictions and former (n,p) experimental results and displayed a good agreement. Due to the good energy resolution, detailed spectroscopic information was obtained, which supplements the data base needed for network calculations for supernova scenarios.

The Ni-64(d,He-2)Co-64 reaction was studied at the AGOR cyclotron of KVI, Groningen, with the Big-Bite Spectrometer and the EuroSuperNova detector using a 171-MeV deuteron beam. An energy resolution of about 110 keV was achieved. In addition to the J(pi) = 1(+) ground state, several other 1(+) states could be identified in Co-64 and the strengths of the corresponding Gamow-Teller transitions were determined. The obtained strength distribution was compared with theoretical predictions and former (n,p) experimental results and displayed a good agreement. Due to the good energy resolution, detailed spectroscopic information was obtained, which supplements the data base needed for network calculations for supernova scenarios.

We have used the (d,He-2) reaction to obtain the GT(+) strength distribution for Sn-116 ->In-116 transitions. Here, In-116 is the intermediate nucleus in the second-order perturbative description of Cd-116 double beta (beta beta) decay. In this paper we will review what is known about the nuclear matrix elements for the Cd-116 2 nu beta beta decay, discuss the single-state dominance hypothesis and combine our new data with other existing data from charge-exchange reactions to obtain a 2 nu beta beta-decay half-life. The deduced value T-1/2=(4 +/- 1)x10(19)y compares well with the one known from direct counting experiments.

The two-neutrino double-beta (2nubetabeta) decay represents a test case for our knowledge about the nuclear structure of the involved isobars. The decay of Ca-48 is an especially interesting case because it holds an anomaly of a uniquely high Q(betabeta) value and a comparatively long half-life, which points to a peculiar nuclear structure situation. The nuclear matrix element relevant for betabeta decay can be calculated, if the complete set of Gamow-Teller (GT) matrix elements for the two virtual transitions in the perturbative description are known. Using the high-resolution (d, He-2) probe, we have measured the GT(+) strength distribution in Sc-48, which is the intermediate nucleus in the Ca-48 betabeta decay. By combining our measured GT distribution with data from a Ca-48(p, n) experiment and taking into account relative phases between individual matrix elements, which can be gained from theoretical models, one can compute the double-GT matrix element and deduce the half-life of the Ca-48 2nubetabeta decay.

The two-neutrino double-beta (2nubetabeta) decay represents a test case for our knowledge about the nuclear structure of the involved isobars. The decay of Ca-48 is an especially interesting case because it holds an anomaly of a uniquely high Q(betabeta) value and a comparatively long half-life, which points to a peculiar nuclear structure situation. The nuclear matrix element relevant for betabeta decay can be calculated, if the complete set of Gamow-Teller (GT) matrix elements for the two virtual transitions in the perturbative description are known. Using the high-resolution (d, He-2) probe, we have measured the GT(+) strength distribution in Sc-48, which is the intermediate nucleus in the Ca-48 betabeta decay. By combining our measured GT distribution with data from a Ca-48(p, n) experiment and taking into account relative phases between individual matrix elements, which can be gained from theoretical models, one can compute the double-GT matrix element and deduce the half-life of the Ca-48 2nubetabeta decay.

Angular distributions for elastic and inelastic deuteron scattering on C-12. Mg-24, and Ni-58 have been measured at a bombarding energy of 170 MeV. The data are analyzed in terms of the optical model. The extracted optical model parameters are compared to existing deuteron global optical potentials.

Angular distributions for elastic and inelastic deuteron scattering on C-12. Mg-24, and Ni-58 have been measured at a bombarding energy of 170 MeV. The data are analyzed in terms of the optical model. The extracted optical model parameters are compared to existing deuteron global optical potentials.