Ground State of Three Alpha Particles

1968 ◽  
Vol 172 (4) ◽  
pp. 1062-1064 ◽  
Author(s):  
J. R. Fulco ◽  
D. Y. Wong
Keyword(s):  
Ground State ◽  
Alpha Particles

scholarly journals Alpha?Particles from the Reaction 7Li(p,g)8Be(a)4He

1960 ◽  
Vol 13 (2) ◽  
pp. 116 ◽  
Author(s):  
DS Gemmell
Keyword(s):  
Ground State ◽  
Alpha Particles ◽  
Particle Spectrum ◽  
Dispersion Formula

The OI:-particle spectrum from the reaction 7Li(p,y)8Be*(0I:)4He has been determined in coincidence with y-rays_ The results indicate that, apart from the broad 2� 9 MeV level, there are no additional levels between the ground state and 7 MeV with intensities greater than 3 per cent. of the 2 . 9 MeV level. It is shown that the shape of the 2 -9 MeV level can be fitted satisfactorily by a dispersion formula if a large value for the reduced width of the level is assumed.

ANGULAR DISTRIBUTIONS IN GAMMA–ALPHA REACTIONS IN THE NUCLEI OF NUCLEAR EMULSIONS

1965 ◽  
Vol 43 (6) ◽  
pp. 1015-1019 ◽  
Author(s):  
Jan P. Roalsvig
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Ground State ◽  
Intensity Ratio ◽  
Alpha Particles ◽  
Angular Distributions ◽  
Nuclear Emulsions

The angular distribution for alpha particles produced by (γ, α) reactions in the nuclei of nuclear emulsions has been measured. For the reaction 16O(γ, α)12C, in which the 12C nucleus is left in its ground state (J = 0+, T = 0), through an excited state at 12.5 MeV in 16O, the angular distribution is in agreement with a mixture of E1 and E2 interactions, with an E2/E1 intensity ratio of 0.50. For the same reaction, through an excited state at 14.3 MeV in 16O, the angular distribution is best represented by a pure E2 interaction.

EVIDENCE FOR LOW-MOMENTUM-TRANSFER PROCESS IN K41 (α,n)Sc44m,g REACTIONS FROM RANGE MEASUREMENTS OF PRODUCTS

1961 ◽  
Vol 39 (3) ◽  
pp. 697-705 ◽  
Author(s):  
Taku Matsuo ◽  
T. T. Sugihara
Keyword(s):  
Momentum Transfer ◽  
Compound Nucleus ◽  
Transfer Process ◽  
Ground State ◽  
Energy Region ◽  
Thick Target ◽  
Alpha Particles ◽  
Direct Reaction ◽  
Range Distribution ◽  
Lower Limits

Average forward ranges have been measured for the product nuclides Sc43, Sc44m, and Sc44g as produced in the reactions K41(α,xn) with alpha particles in the energy region 23 to 39 Mev. These ranges, which are determined by a thick target – thick catcher technique, indicate that the (α,n)-produced isomers are formed in part by a low-momentum-transfer process above 30 Mev, its contribution being larger for the ground-state nuclide Sc44g. From a thick target –thin catcher experiment at 40 Mev, it is found that the range distribution for Sc43 is that expected for a compound-nucleus reaction. Normalizing the Sc44m and Sc44g activity distributions to that of Sc43 for the catchers farthest from the target, we estimate the lower limits for the contribution of a direct-reaction low-momentum-transfer process to the formation of Sc44m and Sc44g at 40 Mev to be about 30% and 46% respectively.

THE ANGULAR DISTRIBUTION AND YIELD OF THE REACTION F19(p, α0)O16

1957 ◽  
Vol 35 (2) ◽  
pp. 155-167 ◽  
Author(s):  
R. L. Clarke ◽  
E. B. Paul
Keyword(s):  
Angular Distribution ◽  
Least Squares ◽  
Cross Sections ◽  
Legendre Polynomial ◽  
Ground State ◽  
Energy Region ◽  
Alpha Particles ◽  
Angular Distributions ◽  
Method Of Least Squares ◽  
Channel Spin

The yield of the ground state alpha particles from the F19(p, α0)O16 reaction has been studied from an energy of 1.3 Mev. to 2.7 Mev. The observed angular distributions were analyzed in terms of a Legendre polynomial expansion by the method of least squares. Six resonances were found in the energy region studied, at bombarding energies of 1.358 Mev., 1.709 Mev., 1.853 Mev., 2.11 Mev., 2.31 Mev., and 2.58 Mev. The widths and peak cross sections of these resonances are respectively: (54 ± 10 kev., 46 ± 5 mb.), (140 ± 5 kev., 55 ± 6 mb.), (132 ± 5 kev., 77 ± 8 mb.), (75 ± 25 kev., 10 ± 2 mb.), (80 ± 25 kev., 32 ± 5 mb.), and (300 ± 25 kev., 51 ± 10 mb.). Their spins, parities, channel spin mixtures, and partial widths are discussed.

scholarly journals PROBING PRE-FORMED ALPHA PARTICLES IN THE GROUND STATE OF NUCLEI

2011 ◽  
Vol 20 (04) ◽  
pp. 1038-1041
Author(s):  
J.A. SCARPACI ◽  
M. FALLOT ◽  
D. LACROIX ◽  
M. ASSIÉ ◽  
L. LEFEBVRE ◽  
...  
Keyword(s):  
Alpha Particle ◽  
Ground State ◽  
Short Range ◽  
Daughter Nucleus ◽  
Alpha Particles ◽  
Particle Properties ◽  
Dependent Theory ◽  
Collision Partner ◽  
Alpha Cluster ◽  
The Continuum

In this proceeding we report on alpha particle emission through the nuclear break-up in the reaction 40 Ca on a 40 Ca target at 50A MeV. It is observed that alpha particles are emitted to the continuum with very specific angular distribution during the reaction. The alpha particle properties seem to be compatible with an alpha cluster in the daughter nucleus that is perturbed by the short range nuclear attraction of the collision partner and emitted as described by a time-dependent theory. This mechanism offers new possibilities to study alpha particle properties in the nuclear medium.

STUDY OF "CONDENSATE" STATES IN 12C AND 16O BY INELASTIC SCATTERING

2008 ◽  
Vol 17 (10) ◽  
pp. 2118-2123 ◽  
Author(s):  
A. S. DEMYANOVA ◽  
A. A. OGLOBLIN ◽  
S. A. GONCHAROV ◽  
T. L. BELYAEVA
Keyword(s):  
Inelastic Scattering ◽  
Excited States ◽  
Ground State ◽  
Transfer Reaction ◽  
Alpha Particles ◽  
Angular Distributions ◽  
Hoyle State

Study of some properties of the lowest states of 12 C , including the second 0+, 7.65 MeV (Hoyle) state by inelastic scattering of alpha-particles and 3 He were carried out. Two independent methods of measuring the radii of the short-lived excited states based on the analysis of diffraction and rainbow patterns of the angular distributions were proposed. Both methods showed that Hoyle state radius is by factor ~ 1.2 – 1.3 larger than that of the ground state. 8 Be transfer reaction was identified. The probability of L = 0 configuration in Hoyle state occurred to be 3 times larger than in the ground state indicating to the significant presence of condensate configuration in the former one.

Production of 8Be in 20 GeV/c proton interactions with the heavy nuclei of nuclear emulsion

1969 ◽  
Vol 47 (2) ◽  
pp. 227-231 ◽  
Author(s):  
G. C. Deka ◽  
K. C. Deka
Keyword(s):  
Ground State ◽  
Nuclear Emulsion ◽  
Alpha Particles ◽  
Angular Distributions ◽  
Heavy Nuclei ◽  
Q Value ◽  
The Mean ◽  
Energy And Angular Distributions ◽  
Parameter Values ◽  
Good Agreement

An analysis of 271 collimated pairs of alpha particles of comparable ranges emitted from interactions of 20 GeV/c protons with the heavy nuclei of emulsion has been made; ~90% of these can be interpreted as due to the decay of 8Be in its ground state. The mean Q value (~0.094 MeV) obtained from the analysis is in good agreement with the expected Q value of the reaction 8Be → 24He. The energy and angular distributions of the 8Be nuclei have been compared with the predictions of the nuclear "evaporation" theory. The parameter values for good fit are found to be: T = 10 MeV, V = 10 MeV, and β = 0.015.

THE APPLICATION OF THSR WAVE FUNCTION USING MONTE CARLO TECHNIQUE

2009 ◽  
Vol 24 (11) ◽  
pp. 2019-2026
Author(s):  
NAOYUKI ITAGAKI ◽  
MASAAKI KIMURA ◽  
MAKOTO ITO ◽  
SHIGEYOSHI AOYAMA ◽  
YUICHI HIRATA
Keyword(s):  
Monte Carlo ◽  
Wave Function ◽  
Ground State ◽  
Coupling Effect ◽  
Threshold Energy ◽  
Closed Shell ◽  
Alpha Particles ◽  
Monte Carlo Technique ◽  
Condensed State ◽  
Neutron Separation Energy

The condensed states of α-clusters or di-neutrons are studied by introducing a Monte Carlo technique for the description of the THSR (Tohsaki Horiuchi Schuck Röpke) wave function. The condensed state of five alpha particles is shown to be stable around the threshold energy even after taking into account the coupling effect between normal cluster states with 16 O +α configurations. Next, the mixing of di-neutron components in 8 He is studied. The ground state of 8 He corresponds to the sub-closed-shell configuration of the spin-orbit favored orbits (p3/2) for the neutrons, and the shell-model-like configuration is considered to be dominant. However, 8 He is a drip-line nucleus with a two-neutron separation energy of 2.1 MeV, and the di-neutron configuration, which is a characteristic feature of the weakly bound systems, mixes in the ground state. Finally, characteristic mechanism for the binding of clusters in neutron-rich nuclei (s2 bond) is discussed.

NEW 5− AND 6+ STATES IN Ne20

1964 ◽  
Vol 42 (3) ◽  
pp. 477-488 ◽  
Author(s):  
J. A. Kuehner ◽  
J. D. Pearson
Keyword(s):  
Excited States ◽  
Rotational Band ◽  
Ground State ◽  
Negative Parity ◽  
Alpha Particles ◽  
Excitation Energies ◽  
Angular Correlations ◽  
Fourth Member

Excited states of Ne20 at excitation energies of 8.46 Mev and 8.79 Mev have been identified and assigned spin and parity values of 5− and 6+, respectively. The excited states were produced in the C12(C12, α)Ne10 reaction and the spin assignments were made on the basis of angular correlations of the decay alpha particles from these states leaving O16 in its ground state. It is postulated that the 5− state is the fourth member of a K = 2 negative-parity rotational band based on the 2– 4.97-Mev state and that the 6+ state is the fourth member of a K = 0 rotational band based on the 0+ ground state of Ne20.

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