Low-energy spectra of 8He and 10He studied in (t,p) type reactions in inverse kinematics

Missing mass spectra for 8He and 10He obtained in the reactions 3H( 6He, p) 8He and 3H( 8He, p) 10He, respectively, are presented.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Low-Energy Spectra of 8^{8}He and 10^{10}He Studied in (t,p) Type Reactions in Inverse Kinematics

International audienceMissing mass spectra for 8He and 10He obtained in the reactions 3H(6He, p)8He and 3H(8He, p)10He, respectively, are presented

Properties of very n-rich He isotopes

International audienceLow-energy spectra of the 8,10He nuclei were investigated in the (t, p)-type reactions at small centre-of-mass angles using ∼ 25AMeV beams of 6He and 8He nuclei. The 0+ ground state (g.s.) of 8He and excited states, 2+ at 3.6-3.9MeV and (1+) at 5.3-5.5MeV, were populated with cross-sections of 200, 100-250, and 90-125 μb/sr, respectively. To account for a near-threshold anomaly observed in the 8He spectrum the population of a 1− continuum (soft dipole excitation) was considered. The lowest-energy group of events in the 10He spectrum was observed at ∼ 3MeV with a cross-section of ∼ 140 μb/sr. This result is consistent with the previously reported observation of 10He providing a new g.s. position for 10He at about 3MeV

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

JINR U-400M cyclotron, separator ACCULINNAThe 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 Me

Properties of very n-rich He isotopes

Low-energy spectra of the 8,10He nuclei were investigated in the (t, p) -type reactions at small centre-of-mass angles using ̃ 25 AMeV beams of 6He and 8He nuclei. The 0+ ground state (g. s.) of 8He and excited states, 2+ at 3. 6-3. 9MeV and (1+) at 5. 3-5. 5MeV, were populated with cross-sections of 200, 100-250, and 90-125μb/sr, respectively. To account for a near-threshold anomaly observed in the 8He spectrum the population of a 1- continuum (soft dipole excitation) was considered. The lowest-energy group of events in the 10He spectrum was observed at ̃ 3 MeV with a cross-section of ̃ 140 μb/sr. This result is consistent with the previously reported observation of 10He providing a new g. s. position for 10He at about 3MeV. © Societá Italiana di Fisica / Springer-Verlag 2009.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Soft dipole mode in 8He

The low-lying spectrum of 8He was studied in the 3H(6He, p)8He transfer reaction for small center of mass angles. 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. Some evidence for the excited state at about 7.5 MeV can be found in the data. The possible nature of the near-threshold anomaly above 2.14 MeV in 8He is related to the population of a 1- continuum (soft dipole excitation) with a peak energy value at about 3 MeV. This assumption can probably resolve the problem of a large uncertainty existing in the experimental data on the 8He 2+ state energy. © Pleiades Publishing, Ltd. 2009.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

New insights into the resonance states of 5H and 5He

The 5H system was produced in the 3H(t, p) 5H reaction studied at small CM angles with a 58MeV tritium ion beam. High statistics data were used to reconstruct the energy and angular correlations between the 5H decay fragments. A broad structure in the 5H missing-mass spectrum showing up above 2.5MeV was identified as a mixture of the 3/2+ and 5/2+ states. The data also present an evidence that the 1/2+ ground state of 5H is located at about 2MeV. Then, the 5H and 5He systems were explored by means of transfer reactions occurring in the interactions of 132MeV 6He beam nuclei with deuterium. In the 2H( 6He, 3H) reaction a T = 3/2 isobaric analog state of 5H in 5He was observed at an excitation energy of 22.0±0.3MeV with a width of 2.5±0.3MeV. © Società Italiana di Fisica / Springer-Verlag 2005.SCOPUS: cp.jinfo:eu-repo/semantics/publishe