252Cf Fission Fragment Energy Loss Measurements in Elementary Gases and Solids as Compared with Theory

1971 ◽  
Vol 49 (23) ◽  
pp. 3024-3035 ◽  
Author(s):  
M. Hakim ◽  
N. H. Shafrir
Keyword(s):  
Energy Loss ◽  
Entire Range ◽  
Heavy Ion ◽  
Electronic Energy ◽  
Surface Barrier ◽  
Loss Mechanism ◽  
Fission Fragments ◽  
Wide Range ◽  
Semi Empirical ◽  
Good Agreement

Energy loss of 252Cf fission fragments in 15 gases and solids, representing a wide range of atomic numbers throughout the periodic system, has been measured using a calibrated Si surface barrier heavy ion detector. The data are used for a detailed and systematic comparison with existing theoretical treatments of the electronic energy loss mechanism showing that none of them gives overall good agreement for all stopping substances.The Bohr expression for heavy stopping substances, which shows consistent deviation from experiment for the entire range of stopping media, suggests that based on this approach, a semi-empirical modification can be derived.

Semi-Empirical Approach for Fission Fragment Energy Degradation in any Elementary Medium

1971 ◽  
Vol 49 (23) ◽  
pp. 3036-3040 ◽  
Author(s):  
M. Hakim ◽  
N. H. Shafrir
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Physical State ◽  
Empirical Equation ◽  
Electronic Energy ◽  
Fission Fragments ◽  
Fitting Procedure ◽  
Wide Range ◽  
Energy Degradation ◽  
Semi Empirical

A semi-empirical equation for the electronic energy loss of fission fragments has been derived by fitting the theoretical approach of Bohr, specifically developed for heavy stopping materials, to experimental data in gases and solids in a wide range of atomic numbers. The fitting procedure was performed by choosing a different expression for the number of electrons of the medium taking part in the stopping process, which includes empirical parameters obtained by fitting to experiment.The equation enables the energy loss of fission fragments in substances of any Z2, regardless of their physical state, to be predicted to a good degree of accuracy down to energies of approximately 20 MeV.

scholarly journals DFT calculation and assignment of vibrational spectra of aryl and alkyl chlorophosphates

2014 ◽  
Vol 12 (2) ◽  
pp. 153-163
Author(s):  
Viktor Anishchenko ◽  
Vladimir Rybachenko ◽  
Konstantin Chotiy ◽  
Andrey Redko
Keyword(s):  
Vibrational Spectra ◽  
Basis Sets ◽  
Heavy Atoms ◽  
Wide Range ◽  
Complete Assignment ◽  
Key Factor ◽  
Polarization Functions ◽  
Experimental Values ◽  
Semi Empirical ◽  
Good Agreement

AbstractDFT calculations of vibrational spectra of chlorophosphates using wide range of basis sets and hybrid functionals were performed. Good agreement between calculated and experimental vibrational spectra was reached by the combination of non-empirical functional PBE0 with both middle and large basis sets. The frequencies of the stretching vibrations of the phosphate group calculated using semi-empirical functional B3LYP for all basis sets deviate significantly from the experimental values. The number of polarization functions on heavy atoms was shown to be a key factor for the calculation of vibrational frequencies of organophosphates. The importance of consideration of all the stable rotamers for a complete assignment of fundamental modes was shown.

scholarly journals Heavy flavour energy loss from AdS/CFT: A novel diffusion coefficient

2018 ◽  
Vol 171 ◽  
pp. 18002 ◽  
Author(s):  
R. Hambrock ◽  
W. A. Horowitz
Keyword(s):  
Diffusion Coefficient ◽  
Energy Loss ◽  
D Meson ◽  
Heavy Ion ◽  
Strongly Coupled ◽  
Azimuthal Correlations ◽  
Ion Collisions ◽  
Order Of Magnitude ◽  
Magnitude Difference ◽  
Good Agreement

Two AdS/CFT based energy loss models are used to compute the suppression and azimuthal correlations of heavy quarks in heavy ion collisions. The model with a velocity independent diffusion coefficient is in good agreement with B and D meson data up to high pT. The partonic azimuthal correlations we calculate exhibit an order of magnitude difference in low momentum correlations to pQCD calculations [1]. We thus propose heavy flavour momentum correlations as a distinguishing observable of weaklyand strongly-coupled energy loss mechanisms.

scholarly journals Properties of Full Jet in High-Energy Heavy-Ion Collisions from Parton Scatterings

2015 ◽  
Vol 2015 ◽  
pp. 1-12
Author(s):  
Guo-Liang Ma ◽  
Mao-Wu Nie
Keyword(s):  
Energy Loss ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
High Energy ◽  
Azimuthal Anisotropy ◽  
Strong Interactions ◽  
Loss Mechanism ◽  
Ion Collisions ◽  
Jet Energy ◽  
Partonic Matter

The properties of fully reconstructed jet are investigated in p + p and Pb + Pb collisions atsNN= 2.76 TeV within a multiphase transport (AMPT) model with both partonic scatterings and hadronic rescatterings. A large transverse momentum (pT) asymmetry of dijet or photon-jet arises from the strong interactions between jet and partonic matter. Theξ-dependent jet fragmentation function in Pb + Pb collisions is decomposed into two contributions from different jet hadronization mechanisms, that is, fragmentation versus coalescence. The medium modification of differential jet shape displays that the jet energy is redistributed towards a larger radius owing to jet-medium interactions in heavy-ion collisions. Jet triangular azimuthal anisotropy coefficient,v3jet, which shows a smaller magnitude than the elliptic coefficientv2jet, decreases more quickly with increasing jetpT, which can be attributed to a path-length effect of jet energy loss. All of these properties of full jet are consistent with the jet energy loss mechanism in a stronglyinteracting partonic matter in high-energy heavy-ion collisions.

Electronic-energy-loss-assisted creep in heavy-ion-irradiated amorphous Fe85B15

1989 ◽  
Vol 39 (1-4) ◽  
pp. 18-21 ◽  
Author(s):  
A. Audouard ◽  
E. Balanzat ◽  
J.C. Jousset ◽  
G. Fuchs ◽  
D. Lesueur ◽  
...  
Keyword(s):  
Energy Loss ◽  
Heavy Ion ◽  
Electronic Energy

High-Energy Heavy-Ion Irradiations of Fe 85 B 15 Amorphous Alloy: Evidence for Electronic Energy Loss Effect

1987 ◽  
Vol 3 (3) ◽  
pp. 327-331 ◽  
Author(s):  
A Audouard ◽  
E Balanzat ◽  
G Fuchs ◽  
J. C Jousset ◽  
D Lesueur ◽  
...  
Keyword(s):  
Amorphous Alloy ◽  
Energy Loss ◽  
Heavy Ion ◽  
High Energy ◽  
Electronic Energy ◽  
Loss Effect

Ball Bearing Response to Cage Unbalance

1986 ◽  
Vol 108 (3) ◽  
pp. 462-466 ◽  
Author(s):  
P. K. Gupta ◽  
J. F. Dill ◽  
J. W. Artuso ◽  
N. H. Forster
Keyword(s):  
Entire Range ◽  
High Speed ◽  
Ball Bearing ◽  
Operating Conditions ◽  
Angular Contact Ball Bearing ◽  
Turbine Engine ◽  
Wide Range ◽  
Inner Race ◽  
Good Agreement ◽  
Engine Bearing

Motion of the cage in a high-speed angular contact ball bearing is experimentally investigated as a function of prescribed unbalance, up to operating speeds corresponding to three million DN. The predictions of cage motion made by the recently developed computer model, ADORE, are validated in the light of the experimental data. It is shown the cage whirl velocity is essentially equal to its angular velocity at all levels of unbalance and over a wide range of operating conditions. For the inner race guided turbine engine bearing, the cage/race interaction takes place directly opposite to the location of the unbalance and the severity of the interaction increases with the level of unbalance and the operating speed. ADORE predictions, over the entire range of unbalance and bearing operating conditions, are in very good agreement with the experimental observations.

scholarly journals Swelling of SiO2 Quartz Induced by Energetic Heavy Ions

1997 ◽  
Vol 504 ◽  
Author(s):  
C. Trautmann ◽  
J. M. Costantini ◽  
A. Meftah ◽  
K. Schwartz ◽  
J. P. Stoquert ◽  
...  
Keyword(s):  
Energy Loss ◽  
Heavy Ions ◽  
Sample Surface ◽  
Critical Energy ◽  
Electronic Energy ◽  
Step Height ◽  
Border Line ◽  
Projected Range ◽  
Out Of Plane ◽  
Good Agreement

ABSTRACTA pronounced swelling effect occurs when irradiating SiO2 quartz with heavy ions (F, S, Cu, Kr, Xe, Ta, and Pb) in the electronic energy loss regime. Using a profilometer, the out-of-plane swelling was measured by scanning over the border line between an irradiated and a virgin area of the sample surface. The step height varied between 20 and 300 nm depending on the fluence, the electronic energy loss and the total range of the ions. From complementary Rutherford backscattering experiments under channelling condition (RBS-C), the damage fraction and corresponding track radii were extracted. Normalising the step height per incoming ion and by the projected range, a critical energy loss of 1.8 ± 0.5 keV/nm was found which is in good agreement with the threshold observed by RBS-C. Swelling can be explained by the amorphisation induced along the ion trajectories. The experimental results in quartz are compared to swelling data obtained under similar irradiation conditions in LiNbO3

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