Th. Kihm

Study of the (d, 3He) reaction on 84Kr and 86Kr and the lowest moments of the proton strength distributions in the Zr region

Abstract Spins and parities of states in 83 Br and 85 Br were determined from angular distributions of cross sections σ(θ) and analyzing powers iT 11 ( θ ) measured in the ( d , 3 He) reaction on 84 Kr and 86 Kr. Broad, unresolved structures between 3 MeV and 10 MeV excitation energy were attributed to the deeply bound, highly fragmented 1f 7 2 shell. The lowest moments of the proton strength distributions observed in pickup and stripping experiments on a number of nuclei in the Zr region were determined and systematic properties of single particle energies and spreading widths were deduced.

Hole-strength distributions from the 34S(d, 3He)33P and 34S(d, t)33S reactions

Abstract A vector-polarized deuteron beam of 52 MeV was used to excite proton and neutron hole states via the 34 S( d , 3 He) 33 P and the 34 S( d , t) 33 S reactions. From the measured angular distributions of differential cross sections σ(θ) and analyzing powers T 11 ( θ ) we determined the spins of 9 states in 33 P and of 13 states in 33 S. The comparison of proton and neutron pick-up spectra yields isospin assignments for 33 S states (T = 1 2 , 3 2 ). Spectroscopic factors deduced from a DWBA analysis were used to determine the lowest moments of the strengths distributions in 33 P and 33 S. Combined with proton and neutron stripping data we calculate ground state occupancies and single-particle energies for 34 S and determine the Fermi surfaces for protons and neutrons. This information allows the application of a recently published sum rule to predict Gamow-Teller strengths S + and S − . Combined with previous data the extracted single-particle energies exhibit systematic features which we parametrise as linear functions of mass number A and isospin To for target nuclei with 28 ⩽ A ⩽ 52. The parameters are closely related to effective particle-hole interactions.

The mass of 35P and spin-parity assignments for excited 35P states

The 36S(d,3He)35P reaction was studied with 52 MeV unpolarized and vector-polarized deuterons. The mass excess of 35P was determined to be −24859±2 keV. Angular distributions of the differential cross sections dσ(θ)dω and the analyzing powers iT11(θ) for strongly excited states were measured. Excitation energies of various proton hole states were determined and the respective values of spin and parity were assigned. The DWBA analysis shows that these states exhaust nearly the complete pickup strength of the (2s,1d) shell.

Reorientation effects for 52 MeV vector polarized deuterons

Abstract The differential cross sections, d σ(θ) d Ω , and the vector analysing powers, iT 11 ( θ ), were measured for the elastic and inelastic scattering of 52 MeV vector polarized douterons from 20 Ne, 22 Ne, 26 Mg, 28 Si, 32 S, 34 S, 36 Ar and 40 Ar nuclei. Coupled channels analysis was carried out using an axially symmetric rotational model with either prolate or oblate quadrupole deformations for each isotope. Calculations assuming harmonic vibrator model were also carried out. In general, reorientation effects were found to be weak. A global optical model potential containing an imaginary spin-orbit component was found to be the most suitable in describing the experimental data at this energy.

Spins and parities of hole states in25Na and25Mg

AbstractAngular distributions of differential cross sections and vector analyzing powers were measured forl=0, 1 and 2 transitions induced by the

Study of proton-hole states in 63Cu and 63Co (I). Spectroscopy of (d, 3He) reactions at Ed = 52MeV

^{26} Mg\left( {\overrightarrow d ,\tau } \right)^{25} Na

Study of charge symmetry in 4He by simultaneous 4He(e,e'p)3H and 4He(e,e'n)3He measurements.

reaction at 52 MeV. The following spins and parities of final states in25Na were deduced:Jπ=1/2+ (1.069 MeV), 3/2+ (2.202 MeV), 5/2+ (2.914 MeV), 1/2− (3.995 MeV) and 3/2− (5.190, 5.690, 6.549 and 7.603 MeV). The DWBA analysis of proton and neutron pick-up spectra obtained from a parallel measurement of the26Mg(d, τ)25Na and26Mg(d, t)25Mg reactions allows the identification ofT=3/2 analog states in25Mg. Interpretation in terms of the Nilsson model of energies and spectroscopic factors of the first 1/2− and 3/2− hole states observed in proton pick-up reactions from even 1d5/2- shell nuclei indicates a close correspondence of the final state deformations with those of the first excited 2+ states in the target nuclei.

Study of charge symmetry in sup 4 He by simultaneous sup 4 He( e , e prime p ) sup 3 H and sup 4 He( e , e prime n ) sup 3 He measurements

Abstract A vector-polarized deuteron beam of 52 MeV was used to excite proton-hole states via the ( d , 3 He) reaction on 36 Ar, 38 Ar and 40 Ar. From the measured angular distributions of differential cross sections σ(θ) and analyzing powers iT 11 ( θ ) we determined spins and parities J π = 1 2 + , 3 2 + 5 2 + and 1 2 − of a number of isolated levels in 36 Cl, 37 Cl and 39 Cl and the complete 1d hole strength distribution in the continuum region. Relative proton occupancies, single-particle energies, the shape of the Fermi surface and spreading widths were obtained from a combined analysis with proton stripping reactions on even argon isotopes. The deduced Id spin-orbit splitting is found to be consistent with the recently observed dependence on main quantum number n and mass number A . The mass excess of 39 Cl was determined to be (−29798 ± 2.8) keV compared to a value of (−29804 ± 19) keV as given in the mass tables.