Two-proton radioactivity of ground and excited states within a unified fission model

The observation of delayed proton emission is reported. Bombardment of both aluminum and silicon with 97-Mev protons leads to the emission of delayed proton energy groups from 2 to 5 Mev. They follow the beta decay of Si25 (T1/2 about 0.3 sec) to proton-unstable excited states of Al25. Delayed protons were also observed following bombardment of Mg, Na, F, N, and O. The energy groups in the delayed proton spectra are explained by assuming that, in each case, a nuclide whose (Z, N) is of the form (2k + 2, 2k − 1) is the parent nuclide, the decay chain being of the form:[Formula: see text]The observed delayed proton energies are those deduced by assuming that known levels of the intermediate nucleus emit the protons. Agreement of this kind, together with cross bombardment, threshold, and lifetime measurements, established the observation of the previously unreported Si25. With less experimental detail, delayed protons have been assigned to the decay schemes of the previously unreported Mg21, Ne17, and O13.

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TWO PROTON RADIOACTIVITY OF 18Ne

International Journal of Modern Physics E ◽

10.1142/s021830131001559x ◽

2010 ◽

Vol 19 (05n06) ◽

pp. 1141-1147

Author(s):

F. GIACOPPO ◽

G. RACITI ◽

E. RAPISARDA ◽

G. CARDELLA ◽

C. SFIENTI ◽

...

Keyword(s):

Excited States ◽

Incident Energy ◽

Coulomb Excitation ◽

Branching Ratio ◽

Proton Decay ◽

Interaction Process ◽

Secondary Beam ◽

Energy Correlation ◽

Secondary Target ◽

Proton Radioactivity

The decay of 18 Ne excited states into 2 p +16 O channel has been studied. The 18 Ne secondary beam, at 33 AMeV incident energy, was produced by fragmentation of a primary 20 Ne beam at the LNS-FRIBs facility. Coulomb excitation on a nat Pb secondary target was found to be the main interaction process leading to the population of 18 Ne excited levels. The two-proton decay of the 6.15 MeV (1-) level has been detected, but in addition other high-lying states decaying via 2 p emission were observed. A significant branching ratio of 2 He decay has been deduced from the analysis of the relative angle and energy correlation spectra of the two protons emitted from the 6.15 MeV (1-) state.

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2He DECAY FROM EXCITED STATES: THE 18Ne CASE

International Journal of Modern Physics E ◽

10.1142/s021830131101909x ◽

2011 ◽

Vol 20 (04) ◽

pp. 976-979 ◽

Cited By ~ 1

Author(s):

G. RACITI ◽

M. DE NAPOLI ◽

E. RAPISARDA ◽

G. CARDELLA ◽

F. GIACOPPO ◽

...

Keyword(s):

Excited States ◽

Proton Decay ◽

Beam Line ◽

Relative Momentum ◽

Radioactive Beams ◽

Sequential Decay ◽

Fragment Separator ◽

Proton Radioactivity

Two-proton radioactivity studies have been performed on excited states of 18 Ne produced by 20 Ne fragmentation at the FRIBs facility of the Laboratori Nazionali del Sud. The study of the relative-momentum correlations of the two protons allowed to disentangle the diproton, democratic and sequential decay contributions to the 2p emission. In order to extend the study on two-proton decay to other light-masses nuclei, an upgrade of the FRIBs facility is planned. A new configuration of the Fragment Separator would be able to increase the acceptance of the beam line and therefore the yield of the produced radioactive beams. Also the present tagging setup will be modified in view of the gain intensity, in order to sustain the higher foreseen incoming rate. Status and perspectives of the facility will be presented.

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Vuv Spectra Y to Mo

International Astronomical Union Colloquium ◽

10.1017/s0252921100107808 ◽

1988 ◽

Vol 102 ◽

pp. 239

Author(s):

M.S.Z. Chaghtai

Keyword(s):

Excited States ◽

Spectral Analyses ◽

Vuv Spectra

Using R.D. Cowan’s computations (1979) and parametric calculations of Meinders et al (1982), old analyses are thoroughly revised and extended at Aligarh, of Zr III by Khan et al (1981), of Nb IV by Shujauddin et Chaghtai (1985), of Mo V by Tauheed at al (1985). Cabeza et al (1986) confirmed the last one largely.Extensive studies have been reported of the 1–e spectra, Zr IV (Rahimullah et al 1980; Acquista and Reader 1980), Nb V (Shujauddin et al 1982; Kagan et al 1981) and Mo VI (Edlén et al 1985). Some interacting 4p54d2levels of these spectra have been reported from our laboratory, also.Detailed spectral analyses of transitions between excited states have furnished complete energy values for J ≠ 1 levels of these spectra during 1970s and 80s. Shujauddin et al (1982) have worked out Nb VI and Tauheed et al (1984) Mo VII from our lab, while Khan et al (1981) share the work on Zr V with Reader and Acquista (1979).

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