V. V. Perevozchikov

The 8He and 10He spectra studied in the (t, p) reaction

The low-lying spectra of 8He and 10He nuclei were studied in the 3H(6He, p)8He and 3H(8He, p)10He transfer reactions. The 0+ ground state (g.s.) of 8He and excited states, 2+ at 3.6–3.9 MeV and (1+) at 5.3–5.5 MeV, were populated with cross sections of 200, 100–250, and 90–125 μb/sr, respectively. Some evidence for a 8He state at about 7.5 MeV was obtained. We discuss a possible nature of the nearthreshold anomaly above 2.14 MeV in 8He and relate it to the population of a 1− continuum (soft dipole excitation) with a peak value at about 3 MeV. The lowest energy group of events in the 10He spectrum was observed at ∼ 3 MeV with a cross section of ∼ 140 μb/sr. We argue that this result is consistent with the previously reported observation of 10He providing the new 10He g.s. position at about 3 MeV

Evidences for resonance states in 5H

Resonance states of H-5 were investigated through the two-neutron transfer reaction t(t, P)(5) H. A triton beam at 57.5 MeV and a cryogenic liquid tritium target were used. The H-5 missing mass spectrum in triple coincidence, proton + triton + neutron, shows a resonance at 1.8 +/- 0.1 MeV above the t + 2n decay threshold. This energy is in good agreement with the result reported in Phys. Rev. Lett. 87 (2001) 092501. The resonance width, Gamma(intr) less than or equal to 0.5 MeV, is surprisingly small and difficult to reconcile with theory 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

Temperature and density dependence of μ-catalysis cycling rate in dense D/T and H/D/T gas mixtures

AbstractMuon catalyzed dt fusion in dense D/T and H/D/T gas mixtures of hydrogen isotopes is studied by the MCF collaboration at JINR. The measurements were carried out with a high pressure target at the JINR phasotron in the temperature range 300-800 K at mixture densities

Experimental Investigation of Muon-catalyzed dt Fusion in Wide Ranges of D/T Mixture Conditions ¶

\simeq 0.4{\text{ and }} \simeq {\text{0}}{\text{.8 LHD}}

Cryogenic Tritium Target

. Tentative experimental results obtained by several analysis methods are presented.

Hydrogen-4 and Hydrogen-5 from t+t and t+d transfer reactions studied with a 57.5-MeV triton beam

Preliminary data are first presented for the measurements of effective parameters of MCF processes in dense D/T mixtures obtained by a novel method. Results are compared with the ones obtained by the “standard” method.

Soft dipole mode in 8He

A vast program of the experimental investigation of muon-catalyzed dt fusion was performed on the Joint Institute for Nuclear Research phasotron. Parameters of the dt cycle were obtained in a wide range of the D/T mixture conditions: temperatures of 20–800 K, densities of 0.2–1.2 of the liquid hydrogen density (LHD), and tritium concentrations of 15–86%. In this paper, the results obtained are summarized.