P. de Saintignon

Elastic and inelastic scattering of carbon ions at intermediate energies

Abstract Elastic and inelastic scattering have been measured at E lab = 360 MeV and 1016 MeV for the 12 C + 12 C system, as well as elastic scattering for 13 C + 208 Pb at 390 MeV. An optical-model analysis is reported and nuclear surface transparency effects are discussed, together with the energy dependence of the nuclear potential. A DWBA analysis of data on the 2 + , 4.4 MeV state of 12 C is reported and trends in the energy dependence of mean-field excitations are deduced.

Elastic and inelastic scattering of 1.03 GeV 12C projectiles

Abstract Elastic scattering cross sections of 86 MeV/N 12C ions on 12C, NATCa, 89Y and 208Pb targets has been measured together with inelastic scattering to the 4.4 MeV state of 12C. There is some indication for giant (quadrupole) resonance excitation in 40Ca. Optical model and DWBA analyses are reported. Nuclear transparency effect is discussed.

A neutron irradiation facility featuring cryogenic temperatures and dedicated to Large Hadron Collider detector design

Abstract The SARA facility at Grenoble provides the possibility to carry out neutron irradiation studies at both cryogenic and room temperatures, and permits at the same time to measure on-line the deterioration of the electronic performance of the tested circuits. The cryogenic vessel consists of a 101 liquid argon cryostat placed behind the neutron source. A TOF technique was used to measure the neutron energy spectrum produced by the collision of a 20 MeV deuteron beam on a thick Be target. Alanine and thermoluminescent dosimeters were used to determine the neutron and photon doses. The results show that the neutron and the gamma dose components are about 78% and 22%, respectively. The angular distribution of the dose was also measured.

Projectile fragments from 86 MeV/nucleon 12C induced reactions

Abstract An 86 MeV/nucleon 12 C beam has been used to bombard targets of C, Ag and Au. Energy spectra of reaction products with Z = 3−6 and A = 6−12 have been measured at angles between 3° and 20°. A simple fragmentation model, while predicting approximately the gross features of the data, fails to describe the results in detail.

Is there a giant monopole resonance in light nuclei

The monopole strength has been investigated in nuclei with mass A ⩽ 60 by inelastic scattering of 108.5 MeV 3 He particles at very small angles. A monopole transition has been found very close to the giant quadrupole resonance in 27 Al, 40 Ca, 56 Fe and 58,60 Ni. The energy of this transition is discussed in relation with the systematics of the giant monopole resonance, and DWBA analysis is reported.

Inelastic scattering of 108.5 MeV 3He particles at very small momentum transfer to the giant monopole resonance of 90Zr and 208Pb

Abstract Inelastic scattering spectra from the ( 3 He, 3 He′) reaction at 108.5 MeV have been measured down to 1.85° scattering angle on 90 Zr and 208 Pb, allowing a giant monopole resonance study in these nuclei. DWBA analysis is reported.

Proton emission in 58A and 86A MeV 12C-induced heavy-ion reactions

Abstract Inclusive proton spectra from 12 C-induced heavy-ion interactions at 58 A and 86 A MeV have been obtained by using a ΔE − E time-of-flight telescope. The shapes of the energy spectra above 30 MeV for 32°⩽ θ ⩽142° are very similar for five targets ranging from C to Au. The backward spectra can be reproduced both in the picture of a thermalized source characterized by an 11–17 MeV temperature Boltzmann distribution moving with half the beam velocity and in the picture of quasi-elastic nucleon-nucleon scattering from two interacting Fermi spheres. The forward spectra are difficult to reproduce unless a combination of the two descriptions is accepted. The 58 A MeV spectra peak substantially closer to the beam energy per nucleon and show significantly steeper slopes than 86 A MeV spectra.

Study of the high-lying states of 12C by inelastic scattering of hadrons

Abstract Beams of 45 and 155 MeV protons and 60 MeV α-particles have been used to investigate the high-lying continuum of 12 C. Various multipolarities and strengths have been located between the excitation energies of 15 and 30 MeV. Isovector El states have been located at excitation energies between 20 and 30 MeV; E2 states at 15.3 and 18.4 MeV ( T = 0); an E3 state at 21.65 MeV ( T = 0); an E4 state at 19.6 MeV ( T = 0); and a M2 state at 19.2 MeV ( T = 1). The results are analyzed in terms of both collective and microscopic model calculations.

Measurements of the neutron yield and the neutron energy distribution from the 9Be(d,n)10B reaction on a thick Be target at an incident deuteron energy of 20.2 MeV

Abstract A fast neutron irradiation facility has been set up at the SARA cyclotron located in Grenoble. This facility provides the possibility to carry out fast neutron irradiation tests at both cryogenic and ambient temperatures. Neutrons are produced by stopping a 20.2 MeV deuteron beam in a 3 mm thick beryllium target. The angular distribution of the neutron flux and the energy spectra from 0° to 40° with respect to the deuteron beam axis were measured. A neutron fluence in the range of 1014 cm−2 is available per day, with a small gamma contamination and a small thermal neutron flux.

Subthreshold K+ production in heavy ion collisions☆

Abstract The cross section for K+ meson production in collisions of 36Ar ions on a 48Ti target has been measured at an incident energy of 92 MeV per nucleon. A description of the experimental set-up is given. Twelve events attributed to monoenergetic muons following the decay of stopped kaons have been identified. From these events, one infers a production cross section of 240 pb. Data are briefly discussed.