2He DECAY FROM EXCITED STATES: THE 18Ne CASE

2011 ◽  
Vol 20 (04) ◽  
pp. 976-979 ◽  
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.

MEASUREMENT OF TWO-PROTON CORRELATION FROM THE BREAK-UP OF 23Al

2010 ◽  
Vol 19 (05n06) ◽  
pp. 957-964 ◽  
Author(s):  
P. ZHOU ◽  
D. Q. FANG ◽  
Y. G. MA ◽  
X. Z. CAI ◽  
J. G. CHEN ◽  
...  
Keyword(s):  
Excited States ◽  
Rest Frame ◽  
Opening Angle ◽  
Proton Emission ◽  
Radioactive Beams ◽  
Decay Channels ◽  
Fragment Separator ◽  
Decay Products ◽  
Projectile Fragment ◽  
Three Body

Experiments of 23 Al and 22 Mg radioactive beams bombarding a 12 C target at an energy of 60 ~70 A MeV have been performed at the projectile fragment separator beamline (RIPS) in the RIKEN Ring Cyclotron Facility to study the two-proton emission from 23 Al and 22 Mg excited states, respectively. The trajectorie of the decay products, namely 21 Na + p + p from 23 Al and 20 Ne + p + p from 22 Mg , are clean identified. The relative momentum and opening angle between two protons in the rest frame of three body decay channels are obtained by relativistic-kinematics reconstruction. The results demonstrate that there are some di-proton emission components from 2 He cluster for the excited 23 Al and 22 Mg .

TWO PROTON RADIOACTIVITY OF 18Ne

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.

scholarly journals First radioactive beams at ACCULINNA-2 facility and first proposed experiment

2018 ◽  
Vol 177 ◽  
pp. 03001 ◽  
Author(s):  
A.A. Bezbakh ◽  
W. Beekman ◽  
V. Chudoba ◽  
A.S. Fomichev ◽  
M.S. Golovkov ◽  
...  
Keyword(s):  
Focal Plane ◽  
Ion Beams ◽  
Beam Line ◽  
Design Parameters ◽  
Radioactive Ion Beams ◽  
Fragmentation Reaction ◽  
Radioactive Beams ◽  
Fragment Separator ◽  
Transverse Profile ◽  
New Facility

New fragment separator ACCULINNA-2 was installed at the primary beam line of the U-400M cyclotron in 2016. Recently, first radioactive ion beams were obtained. The design parameters of new facility were experimentally confirmed. Intensity, purity and transverse profile of several secondary beams at the final focal plane were studied. The intensities obtained for the secondary beams of 14B, 12Be, 9;11Li, 6;8He in the fragmentation reaction 15N (49.7 AMeV) + Be (2 mm) are in average 15 times higher in comparison to the ones produced at its forerunner ACCULINNA separator. The ACCULINNA-2 separator will become a backbone facility at the FLNR for the research in the field of light exotic nuclei in the vicinity of the nuclear drip lines. The planned first experiment, aimed for the observation of the 7H nucleus at ACCULINNA-2, is outlined.

MEASUREMENT OF THE PROTON-PROTON CORRELATION FUNCTION FROM THE BREAK-UP OF 22Mg AND 20Ne

2010 ◽  
Vol 19 (08n09) ◽  
pp. 1823-1828 ◽  
Author(s):  
X. Y. SUN ◽  
J. G. CHEN ◽  
D. Q. FANG ◽  
Y. G. MA ◽  
X. Z. CAI ◽  
...  
Keyword(s):  
Correlation Function ◽  
Excited States ◽  
Correlation Functions ◽  
Center Of Mass ◽  
Cluster Decay ◽  
Proton Proton ◽  
Fragment Separator ◽  
Angular Correlations ◽  
Momentum Correlation ◽  
Projectile Fragment

An experiment of 22 Mg and 20 Ne beams bombarding on a 12 C target at an energy of 60~70 A MeV has been performed at the RIKEN projectile fragment separator (RIPS) in the RIKEN Ring Cyclotron Facility to study the two-proton correlated emission from 22 Mg and 20 Ne excited states. The two-protons momentum correlation functions have been obtained for 22 Mg and 20 Ne , respectively. The trajectories of the 22 Mg decayed products (20 Ne + p + p ) were also measured to get the angular correlations between the two protons in Center of Mass of decaying system by relativistic-kinematics reconstruction. The results exhibit that 22 Mg has the features of 2 He cluster decay mechanism.

Photoneutron Cross Sections in 14N

1972 ◽  
Vol 50 (15) ◽  
pp. 1689-1696 ◽  
Author(s):  
R. W. Gellie ◽  
K. H. Lokan ◽  
N. K. Sherman ◽  
R. G. Johnson ◽  
J. I. Lodge
Keyword(s):  
Excited States ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Emission ◽  
Giant Resonance ◽  
Sequential Decay ◽  
Dipole Resonance ◽  
Intermediate States ◽  
Integrated Cross Section ◽  
High Degree

Photoneutron distributions from 14N have been obtained by time-of-flight methods, for bremsstrahlung end-point energies increasing in 2 MeV steps from 15.5 to 29.5 MeV. A large part of the neutron yield is associated with the sequential decay of 14N to 12C, through well-defined intermediate states of 13C, at 7.55, 8.86, and 11.80 MeV, which are unstable against neutron emission. The (γ,n0) cross section for neutron emission to the ground state of 13N is found to agree very closely with the corresponding (γ,p0) cross section, implying a high degree of isospin purity for the giant dipole resonance of 14N. It is observed that the decay of the giant resonance proceeds freely through those odd-parity excited states of the A = 13 nuclei which are single hole states formed by the removal of a p-shell nucleon from the parent 14N.The integrated cross section for all neutron-producing interactions is found to be 88 ± 5 MeV mb.

scholarly journals Effect of Excited-state Decays on the Measured Angular Distribution of the 12C(g, p)11B Reaction

1974 ◽  
Vol 27 (3) ◽  
pp. 301 ◽  
Author(s):  
Judith M Dixon ◽  
MN Thompson
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Excited States ◽  
Cross Section ◽  
Proton Decay ◽  
Small Cross Section

The angular distribution of photoprotons from i2e as measured directly and as deduced from the inverse reaction are compared. A discrepancy is revealed; it is resolved by proposing a small cross section for proton decay to excited states of 11 B. The size

scholarly journals Investigation of the Transient Field at High Velocities by magnetic-moment measurements in 74Ge and 70Zn

2019 ◽  
Vol 18 ◽  
pp. 135
Author(s):  
T. J. Mertzimekis
Keyword(s):  
Angular Correlation ◽  
Excited States ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Research Work ◽  
Transient Field ◽  
Radioactive Beams ◽  
Field Technique ◽  
Experiment Method ◽  
Experimental Facilities

The advent of radioactive beams at large experimental facilities has moti- vated extensive research work on the expansion of techniques to accommodate higher ion velocities. The application of the Transient Field technique in measuring magnetic moments of excited states in energetic nuclei is investigated at the INFN-LNS in Catania by means of re-measuring the g(2+1 ) factors in 74Ge and 70Zn. The description of the experiment method and some preliminary angular correlation results are presented.

A Neutron Spectrometer for Experiments with Radioactive Beams on the ACCULINNA-2 Fragment Separator

2018 ◽  
Vol 61 (5) ◽  
pp. 631-638 ◽  
Author(s):  
A. A. Bezbakh ◽  
S. G. Belogurov ◽  
R. Wolski ◽  
E. M. Gazeeva ◽  
M. S. Golovkov ◽  
...  
Keyword(s):  
Radioactive Beams ◽  
Neutron Spectrometer ◽  
Fragment Separator

scholarly journals EMPIRICAL FORMALISM FOR PROJECTILE FRAGMENTATION AND PRODUCTION OF NEW NEUTRON-RICH NUCLEI WITH RIBS

1998 ◽  
Vol 13 (33) ◽  
pp. 2665-2678 ◽  
Author(s):  
DEBASIS BHOWMICK ◽  
ALOK CHAKRABARTI ◽  
D. N. BASU ◽  
PREMOMOY GHOSH ◽  
RANJANA GOSWAMI
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ion Beam ◽  
Production Cross ◽  
High Energy ◽  
Exotic Nuclei ◽  
Radioactive Beams ◽  
Fragment Separator ◽  
Projectile Fragment ◽  
The Cross

The projectile fragment separator type radioactive ion beam (RIB) facilities, being developed in different laboratories, provide the scope for producing many new exotic nuclei through fragmentation of high energy radioactive ion (RI) beams. A new empirical parametrization for the estimation of cross-sections of projectile fragments has been prescribed for studying the advantages and limitations of high energy RI beams for the production of new exotic nuclei. The parametrization reproduces the experimental data for the production of fragments from neutron-rich projectiles accurately in contrast to the existing parametrization which tends to overestimate the cross-section of neutron-rich fragments in most cases. The modified formalism has been used to compute the cross-sections of neutron-rich species produced by fragmentation of radioactive projectiles (RIBs). It has been found that, given any limit of production cross-section, the exoticity of the fragment increases rather slowly and shows a saturation tendency as the projectile is made more and more exotic. This essentially limits, to an extent, the utility of very neutron-rich radioactive beams vis-a-vis production of new neutron-rich exotic species.

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

2021 ◽  
Author(s):  
Fengzhu Xing ◽  
Jianpo Cui ◽  
Yanzhao Wang ◽  
Jian-Zhong 顾建中 Gu
Keyword(s):  
Excited States ◽  
Proton Radioactivity
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