A. M. Rodin

TWO-NEUTRON EXCHANGE OBSERVED IN THE 6HE + 4HE REACTION. SEARCH FOR THE DI-NEUTRON CONFIGURATION OF 6HE

Differential cross sections for the elastic scattering of 6 He exotic nuclei from a gaseous helium target has been measured in a wide angular range in the CM system at a 6 He beam energy of 151 MeV. The large cross-sections obtained at backward angles are discussed in terms of a two-neutron exchange process. The results of DWBA calculations show that this effect can account for the cross sections obtained between 1208 and 1608 assuming the spectroscopic factor to be about 1 for the di-neutron cluster as was predicted by theory for 6 He. q 1998 Published by Elsevier Science B.V. All rights reserved.

Cluster structure of 6He studied by means of 6He + p reaction at 25 MeV/n energy

Abstract Angular distributions for elastic scattering and 1n and 2n transfer reactions were measured for the 6 He + 1 H system at 25 MeV/nucleon. The experimental data were analyzed in the framework of the one-step finite range DWBA model. The results suggest a lower triton spectroscopic amplitude for the 6 He nucleus as compared to the shell model calculation.

24.5 A MeV 6He+p elastic and inelastic scattering

The structure of 6 He is explored with proton elastic and inelastic scattering to the first 2 + excited state (Q =− 1. 8M eV) of 6 He in the inverse kinematics using a 24.5 A MeV 6 He beam. The distorted wave approximation (DWA) with an optical potential obtained by folding an effective nucleon–nucleon (NN) g-matrix with the 6 He density matrix elements as given by a large basis shell model is used to analyse the data. The comparison of predictions with the data confirms the view that 6 He has

Investigation of 6He cluster structures

The +2n and t+t clustering of the 6He ground state were investigated by means of the transfer reaction 6He(p,t)4He at 25 MeV/nucleon. The experiment was performed in inverse kinematics at GANIL with the SPEG spectrometer coupled to the MUST array. Experimental data for the transfer reaction were analyzed by a distorted wave Born approximation (DWBA) calculation, including the two neutrons and the triton transfer. The couplings to the 6He4He+2n breakup channels were taken into account with a polarization potential deduced from a coupled-discretized-continuum channels analysis of the 6He+1H elastic scattering measured at the same time. The influence on the calculations of the +t exit potential and of the triton sequential transfer is discussed. The final calculation gives a spectroscopic factor close to one for the +2n configuration as expected. The spectroscopic factor obtained for the t+t configuration is much smaller than the theoretical predictions.

Status of ACCULINNA beam line

AbstractTheseparatorACCULINNAwasupgradedtoachievenewexperimentalrequirements.Thebeamlinewasextendedbynewion-opticalelementsbeyondthecyclotronhall.Thenewarrangementsyieldmuchbetterbackgroundcondi-tions.Theintensitiesof 6 Heand 8 Heradioactivebeamsproducedinfragmentationof35AMeV 11 Bionswereincreaseduptoafactorof10.Theupgradedbeamlinewasusedinexperimentstostudythe 5 Hresonancestatespopulatedinthet þt reaction.Acryogenicliquidtritiumtargetwasdesignedandinstalledattheseparatorbeamline. 2002ElsevierScienceB.V.Allrightsreserved. PACS:25.70.Mn;29.25.RmKeywords:Radioactive ion beams;Productiontarget;Profileddegrader;Liquidtritiumtarget 1.IntroductionTheseparatorACCULINNA[1]isinoperationsince1996.Highintensityprimarybeamsof 7 Li, 11 B, 13 C, 15 Nand 18 Owithenergyvaluesrangingbetween32and50AMeVaredeliveredbytheU-400Mcyclotrontotheproductiontargetoftheseparator.Thesecondarybeamsof 6 Heand 8 Henucleiwithenergiesofabout25AMeVallowedustogainnewinsightsintothestructureofneutronhalonucleithroughthestudyofone-andtwo-neutrontransferreactionsmadewithhydrogenandheliumtargets[2–5].Suchbeamsofferfavor-ableconditionsfortheproductionofsofarun-knownparticle-unstablenucleibeyondtheneutrondripline.Forthispurposeonecoulduseone-stepone-proton and two-neutron transfer reactionsoccurringwheneither

New insight into the low-energy

The spectrum of

^{9}

^{9}\mathrm{He}

He spectrum

was studied by means of the

Range–energy relation, range straggling and response function of CsI(Tl), BGO and GSO(Ce) scintillators for light ions

^{2}\mathrm{H}

Binary and ternary fission studies with 252Cf

(