scholarly journals Revisiting the photoabsorption spectrum of NH3 in the 5.4–10.8 eV energy region

2019 ◽  
Vol 151 (18) ◽  
pp. 184302 ◽  
Author(s):  
P. Limão-Vieira ◽  
N. C. Jones ◽  
S. V. Hoffmann ◽  
D. Duflot ◽  
M. Mendes ◽  
...  
Keyword(s):  
Energy Region ◽  
Photoabsorption Spectrum

scholarly journals High-Resolution Photoabsorption Spectrum of Cs+ (5p61So + 5p5ns, nd) Between 504A and 600A using a Laser Ionized Cs Vapor Column

1984 ◽  
Vol 86 ◽  
pp. 124-124
Author(s):  
T.J. McIlrath ◽  
V. Kaufman ◽  
J. Sugar ◽  
W.T. Hill ◽  
D. Cooper
Keyword(s):  
High Resolution ◽  
Laser Pulse ◽  
High Voltage ◽  
Power Output ◽  
Random Phase ◽  
Grazing Incidence ◽  
Fano Resonances ◽  
Line Shapes ◽  
Phase Calculation ◽  
Photoabsorption Spectrum

Rapid ionization of Cs vapor in a heat pipe at 0.05 torr was achieved by pumping the 6s 2S½ – 7p 2P½ transition (f=0.007)1 with a flash-pumped dye laser at 4593.2A and I MW power output. Photoabsorptian initiated at the end of the laser pulse(≃ 0.5/s) showed the 5p5ns and nd series below and above the 5p52P3/2 threshold at 535.4A. Broad Beutler - Fano resonances appeared in the d series above threshold. The spectrum was recorded photographically on a 10.7m grazing incidence spectrograph using a continuum background generated by a BRV high-voltage spark source with a uranium anode. We will compare the line-shapes and the quantum defect (Lu-Fano2) plot with the predictions of a relativistic random phase calculation.

The measurement of mean free path λs using a slowing down time lead spectrometer in the 1–10 eV energy region

1968 ◽  
Vol 22 (4) ◽  
pp. 261-262
Author(s):  
M.P. Navalkar ◽  
K. Chandramoleshwar ◽  
D.V.S. Ramkrishna
Keyword(s):  
Free Path ◽  
Energy Region ◽  
Mean Free Path ◽  
Slowing Down ◽  
Time Lead

scholarly journals Analysis of Shielding Performance of Radiation-Shielding Materials According to Particle Size and Clustering Effects

2021 ◽  
Vol 11 (9) ◽  
pp. 4010
Author(s):  
Seon-Chil Kim
Keyword(s):  
Particle Size ◽  
Polymer Material ◽  
Energy Region ◽  
High Energy ◽  
Radiation Shielding ◽  
High Energy Region ◽  
Particle Structure ◽  
Effect Of Particle Size ◽  
Extensive Body ◽  
Shielding Material

In the field of medical radiation shielding, there is an extensive body of research on process technologies for ecofriendly shielding materials that could replace lead. In particular, the particle size and arrangement of the shielding material when blended with a polymer material affect shielding performance. In this study, we observed how the particle size of the shielding material affects shielding performance. Performance and particle structure were observed for every shielding sheet, which were fabricated by mixing microparticles and nanoparticles with a polymer material using the same process. We observed that the smaller the particle size was, the higher both the clustering and shielding effects in the high-energy region. Thus, shielding performance can be improved. In the low-dose region, the effect of particle size on shielding performance was insignificant. Moreover, the shielding sheet in which nanoparticles and microsized particles were mixed showed similar performance to that of the shielding sheet containing only microsized particles. Findings indicate that, when fabricating a shielding sheet using a polymer material, the smaller the particles in the high-energy region are, the better the shielding performance is. However, in the low-energy region, the effect of the particles is insignificant.

scholarly journals Adjustment of Terahertz Properties Assigned to the First Lowest Transition of (D+, X) Excitonic Complex in a Single Spherical Quantum Dot Using Temperature and Pressure

2021 ◽  
Vol 11 (13) ◽  
pp. 5969
Author(s):  
Noreddine Aghoutane ◽  
Laura M. Pérez ◽  
Anton Tiutiunnyk ◽  
David Laroze ◽  
Sotirios Baskoutas ◽  
...  
Keyword(s):  
Refractive Index ◽  
Quantum Dot ◽  
Energy Region ◽  
Practical Importance ◽  
High Energy ◽  
Spherical Quantum Dot ◽  
Terahertz Region ◽  
Mass Approximation ◽  
Optical Responses ◽  
Temperature And Pressure

This theoretical study is devoted to the effects of pressure and temperature on the optoelectronic properties assigned to the first lowest transition of the (D+,X) excitonic complex (exciton-ionized donor) inside a single AlAs/GaAs/AlAs spherical quantum dot. Calculations are performed within the effective mass approximation theory using the variational method. Optical absorption and refractive index as function of the degree of confinement, pressure, and temperature are investigated. Numerical calculation shows that the pressure favors the electron-hole and electron-ionized donor attractions which leads to an enhancement of the binding energy, while an increasing of the temperature tends to reduce it. Our investigations show also that the resonant peaks of the absorption coefficient and the refractive index are located in the terahertz region and they undergo a shift to higher (lower) therahertz frequencies when the pressure (temperature) increases. The opposite effects caused by temperature and pressure have great practical importance because they offer an alternative approach for the adjustment and the control of the optical frequencies resulting from the transition between the fundamental and the first excited state of exciton bound to an ionized dopant. The comparison of the optical properties of exciton, impurity and (D+,X) facilitates the experimental identification of these transitions which are often close. Our investigation shows that the optical responses of (D+,X) are located between the exciton (high energy region) and donor impurity (low energy region) peaks. The whole of these conclusions may lead to the novel light detector or source of terahertz range.

scholarly journals DK I = 0, $$ D\overline{K} $$ I = 0, 1 scattering and the $$ {D}_{s0}^{\ast } $$(2317) from lattice QCD

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Gavin K. C. Cheung ◽  
◽  
Christopher E. Thomas ◽  
David J. Wilson ◽  
Graham Moir ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Scattering Amplitudes ◽  
Lattice Qcd ◽  
Finite Volume ◽  
Energy Region ◽  
Light Quark ◽  
Bound State ◽  
Vector Resonance ◽  
Quark Masses ◽  
Partial Waves

Abstract Elastic scattering amplitudes for I = 0 DK and I = 0, 1 $$ D\overline{K} $$ D K ¯ are computed in S, P and D partial waves using lattice QCD with light-quark masses corresponding to mπ = 239 MeV and mπ = 391 MeV. The S-waves contain interesting features including a near-threshold JP = 0+ bound state in I = 0 DK, corresponding to the $$ {D}_{s0}^{\ast } $$ D s 0 ∗ (2317), with an effect that is clearly visible above threshold, and suggestions of a 0+ virtual bound state in I = 0 $$ D\overline{K} $$ D K ¯ . The S-wave I = 1 $$ D\overline{K} $$ D K ¯ amplitude is found to be weakly repulsive. The computed finite-volume spectra also contain a deeply-bound D* vector resonance, but negligibly small P -wave DK interactions are observed in the energy region considered; the P and D-wave $$ D\overline{K} $$ D K ¯ amplitudes are also small. There is some evidence of 1+ and 2+ resonances in I = 0 DK at higher energies.

scholarly journals Measurement of the running of the fine structure constant below 1 GeV with the KLOE detector

2019 ◽  
Vol 218 ◽  
pp. 02012
Author(s):  
Graziano Venanzoni
Keyword(s):  
Fine Structure ◽  
Energy Region ◽  
Direct Evidence ◽  
Branching Ratio ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Recent Measurement ◽  
Single Measurement ◽  
Lepton Universality ◽  
Hadronic Contribution

I will report on the recent measurement of the fine structure constant below 1 GeV with the KLOE detector. It represents the first measurement of the running of α(s) in this energy region. Our results show a more than 5σ significance of the hadronic contribution to the running of α(s), which is the strongest direct evidence both in time-and space-like regions achieved in a single measurement. From a fit of the real part of Δα(s) and assuming the lepton universality the branching ratio BR(ω → µ+µ−) = (6.6 ± 1.4stat ± 1.7syst) · 10−5 has been determined

scholarly journals π--PInteraction in High Energy Region

1957 ◽  
Vol 18 (3) ◽  
pp. 264-268 ◽  
Author(s):  
Daisuke Ito ◽  
Tetsuro Kobayashi ◽  
Miwae Yamazaki ◽  
Shigeo Minami
Keyword(s):  
Energy Region ◽  
High Energy ◽  
High Energy Region
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