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.

scholarly journals Photodissociation of Iso-Propoxy (I-C3H7O) Radical at 248 Nm

2020 ◽  
Author(s):  
Erin Sullivan ◽  
Steven Saric ◽  
Daniel Neumark
Keyword(s):  
Electronic State ◽  
Ground State ◽  
Branching Ratio ◽  
Ground Electronic State ◽  
Angular Distributions ◽  
Translational Energy ◽  
Energy And Angular Distributions ◽  
Three Body ◽  
State Dissociation

<p>Photodissociation of the <i>i</i>-C<sub>3</sub>H<sub>7</sub>O radical is investigated using fast beam photofragment translational spectroscopy. Neutral <i>i</i>-C<sub>3</sub>H<sub>7</sub>O radicals are produced through the photodetachment of a fast beam of <i>i</i>-C<sub>3</sub>H<sub>7</sub>O<sup>-</sup> anions and are subsequently dissociated using 248 nm (5.0 eV). The dominant product channels are CH<sub>3</sub> + CH<sub>3</sub>CHO and OH + C<sub>3</sub>H<sub>6</sub> with some contribution from H + C<sub>3</sub>H<sub>6</sub>O. CH<sub>3</sub> and H loss are attributed to dissociation on the ground electronic state of <i>i</i>-C<sub>3</sub>H<sub>7</sub>O, but in a nonstatistical manner because RRKM dissociation rates exceed the rate of energy randomization. Translational energy and angular distributions for OH loss are consistent with ground state dissociation, but the branching ratio for this channel is considerably higher than predicted from RRKM rate calculations. These results corroborate what has been observed previously in C<sub>2</sub>H<sub>5</sub>O dissociation at 5.2 eV that yields CH<sub>3</sub>, H, and OH loss. Additionally, <i>i</i>-C<sub>3</sub>H<sub>7</sub>O undergoes three-body fragmentation to CH<sub>3</sub> + CH<sub>3</sub> + HCO and CH<sub>3</sub> + CH<sub>4</sub> + CO. These three-body channels are attributed to dissociation of <i>i</i>-C<sub>3</sub>H<sub>7</sub>O to CH<sub>3</sub> + CH<sub>3</sub>CHO, followed by secondary dissociation of CH<sub>3</sub>CHO on its ground electronic state.</p>

scholarly journals Photodissociation of Iso-Propoxy (I-C3H7O) Radical at 248 Nm

2020 ◽  
Author(s):  
Erin Sullivan ◽  
Steven Saric ◽  
Daniel Neumark
Keyword(s):  
Electronic State ◽  
Ground State ◽  
Branching Ratio ◽  
Ground Electronic State ◽  
Angular Distributions ◽  
Translational Energy ◽  
Energy And Angular Distributions ◽  
Three Body ◽  
State Dissociation

<p>Photodissociation of the <i>i</i>-C<sub>3</sub>H<sub>7</sub>O radical is investigated using fast beam photofragment translational spectroscopy. Neutral <i>i</i>-C<sub>3</sub>H<sub>7</sub>O radicals are produced through the photodetachment of a fast beam of <i>i</i>-C<sub>3</sub>H<sub>7</sub>O<sup>-</sup> anions and are subsequently dissociated using 248 nm (5.0 eV). The dominant product channels are CH<sub>3</sub> + CH<sub>3</sub>CHO and OH + C<sub>3</sub>H<sub>6</sub> with some contribution from H + C<sub>3</sub>H<sub>6</sub>O. CH<sub>3</sub> and H loss are attributed to dissociation on the ground electronic state of <i>i</i>-C<sub>3</sub>H<sub>7</sub>O, but in a nonstatistical manner because RRKM dissociation rates exceed the rate of energy randomization. Translational energy and angular distributions for OH loss are consistent with ground state dissociation, but the branching ratio for this channel is considerably higher than predicted from RRKM rate calculations. These results corroborate what has been observed previously in C<sub>2</sub>H<sub>5</sub>O dissociation at 5.2 eV that yields CH<sub>3</sub>, H, and OH loss. Additionally, <i>i</i>-C<sub>3</sub>H<sub>7</sub>O undergoes three-body fragmentation to CH<sub>3</sub> + CH<sub>3</sub> + HCO and CH<sub>3</sub> + CH<sub>4</sub> + CO. These three-body channels are attributed to dissociation of <i>i</i>-C<sub>3</sub>H<sub>7</sub>O to CH<sub>3</sub> + CH<sub>3</sub>CHO, followed by secondary dissociation of CH<sub>3</sub>CHO on its ground electronic state.</p>

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.

On the computation of dipole transitions in the HD molecule. Part II

1976 ◽  
Vol 54 (6) ◽  
pp. 672-679 ◽  
Author(s):  
L. Wolniewicz
Keyword(s):  
Ground State ◽  
Wave Functions ◽  
Nonadiabatic Coupling ◽  
Transition Moments ◽  
The Mean ◽  
Variational Wave Functions ◽  
Theoretical Results ◽  
Variational Wave ◽  
Electronic Ground ◽  
Good Agreement

The nonadiabatic coupling with Πu states in the electronic ground state of the HD molecule is discussed. Formulas are given that facilitate the evaluation of Πu contributions to the energies and transition moments. Numerical computations are performed for all ν ≤ 4 vibrational and J ≤ 4 rotational levels yielding the Πu and Σu nonadiabatic corrections. The variational wave functions are employed to compute the transition moments for the 0–ν bands with ν ≤ 4. The results are in good agreement with experimental data except in the case of the 0–ν band where the theoretical results are larger than the mean experimental moment by a factor of about 1.4.

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.

A Study of Levels in 149Nd using the (d, t) and (3He, α) Reactions

1973 ◽  
Vol 51 (4) ◽  
pp. 455-464 ◽  
Author(s):  
D. G. Burke ◽  
J. C. Waddington ◽  
D. E. Nelson ◽  
J. Buckley
Keyword(s):  
Cross Sections ◽  
Ground State ◽  
State Transition ◽  
Angular Distributions ◽  
Ground State Transition ◽  
Reaction Products ◽  
Q Value ◽  
Nilsson Model ◽  
Photographic Emulsions ◽  
Peak Widths

Triton spectra from the 150Nd(d, t)149Nd reaction have been measured at 15 angles using beams of 12 MeV deuterons. The 150Nd(3He, α)149Nd reaction was studied at four angles with 24 MeV 3He beams. In all cases the reaction products were analyzed with an Enge-type magnetic spectrograph and detected with photographic emulsions. The peak widths (FWHM) were approximately 8 keV for the (d, t) studies and 25 keV for the (3He, α) spectra. It is now evident that the highest energy triton group ascribed to the 150Nd(d, t)149Nd reaction in previous works does not correspond to the ground state transition. According to the current interpretation the ground state transition has a Q value of −1.122 ± 0.010 MeV. The (d, t) angular distributions and the ratios of (3He, α) and (d, t) cross sections at selected angles were used to determine l values for a number of the transitions. Three states in 149Nd at 481, 813, and 986 keV are definitely populated by l = 0 transitions and thus have Iπ = 1/2+. A strongly perturbed band consisting of a mixture of Nilsson states from the i13/2 shell has been found, with properties similar to the corresponding bands in the isotones 151Sm and 153Gd. The total observed intensity for each of the l values 0, 1, 2, and 6 cannot be explained by the extreme single-particle shell model but is consistent with that predicted by the Nilsson model. However, the splitting of the strength among the observed states cannot be explained by the basic Nilsson model.

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.

THE Sr88(d, p)Sr89 REACTION

1964 ◽  
Vol 42 (2) ◽  
pp. 321-328 ◽  
Author(s):  
R. L. Preston ◽  
M. B. Sampson ◽  
H. J. Martin
Keyword(s):  
Shell Model ◽  
Ground State ◽  
Energy Levels ◽  
Angular Distributions ◽  
Q Value ◽  
Excitation Energies ◽  
Analogous Data ◽  
State Spin

Thirteen energy levels in Sr89 were excited by the Sr88(d, p)Sr89 reaction. The excitation energies of the levels are 0, 1.04, 2.00, 2.44, 2.67, 3.18, 3.45, 3.74, 4.10, 4.44, 4.60, 4.97, and 5.38 Mev. The ground-state Q-value is 4.15 ± 0.04 Mev. Angular distributions were measured for protons leaving Sr89 in the first three levels and for the 3.74-Mev state. Spin assignments were made using the shell model and the DWBA stripping theory. The assignments are 2d5/2 for the ground state, 3s1/2 for the 1.04-Mev state, 2d3/2 for the 2.00-Mev state, and [Formula: see text] for the 3.74-Mev state. The results are compared with analogous data on Zr91 levels.

PROPERTIES OF ALPHA DECAY TO ROTATIONAL BANDS OF HEAVY NUCLEI

2010 ◽  
Vol 19 (10) ◽  
pp. 1961-1971 ◽  
Author(s):  
Y. Z. WANG ◽  
J. Z. GU ◽  
J. M. DONG ◽  
B. B. PENG
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Liquid Drop ◽  
Alpha Decay ◽  
Branching Ratios ◽  
Heavy Nuclei ◽  
Liquid Drop Model ◽  
Α Decay ◽  
Rotational Bands ◽  
Good Agreement

In the framework of the generalized liquid drop model (GLDM) and improved Royer's formula, we investigate the branching ratios and half-lives of α-decay to the members of the ground-state rotational bands of heavy even–even Fm and No isotopes. The calculated results are in good agreement with the available experimental data and some useful predictions are provided for future experiments.

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