The Effect of Super-Radiance on the C-A Transition of the Excimer Molecule XeCl* at 352 nm Excited Only by 235U Fission Fragments
Aleksey Iustinovich Mis’kevich,
Jin Bo Guo,
Yurii Alekseevich Duyzhov,
Anton Viktorovich Podkopaev
Issue:
Volume 8, Issue 2, March 2019
Pages:
14-17
Received:
8 April 2019
Accepted:
30 May 2019
Published:
11 July 2019
Abstract: The work is devoted to the study of spectral, temporal and generation characteristics of plasma generated in dense gas mixtures by the products of neutron nuclear reaction 235U(n, f). This plasma differs in its properties from the discharge plasma, as has the track structure and low temperature of electrons, and the presence in gas mixtures of electronegative gas can become without electrons. On the basis of such nuclear-excited plasma excimer gas lasers with the nuclear pumping, carrying out direct transformation of nuclear energy to the laser radiation UV range of lengths of waves, can be created. We found out high efficiency of formation of excimer molecules of XeCl* in dense (~ 760 Торр) Ar - Xe - CCl 4 of gas mixture with low (~ 1015 mol/cм3) concentration of CCl4 at the nuclear pumping. Here we report the first clear observation of super-radiance at 352 nm on C-A transition of excimer molecule XeCl* excited solely by nuclear pumping Ar-Xe-CCl4 gas mixture at a pressure of 760 Torr with a low concentration of CCl4 (0.15Torr). The mixture was excited by products of neutron nuclear reaction 235U(n,f) pumped at a rate of 2kW/cm3. A laser cell with a length of 100cm was placed inside an optical resonator tuned at 352 nm. Super-radiance had a very sharp increase and low neutron threshold (about 2÷4.1014 neutron/cm2. s) when we used the tuning resonator at 352 nm wavelength with 10.8% reflection of output and 62.1% reflection of back spherical mirrors, and super-radiance disappeared if the laser output mirror was replaced by a quartz window.
Abstract: The work is devoted to the study of spectral, temporal and generation characteristics of plasma generated in dense gas mixtures by the products of neutron nuclear reaction 235U(n, f). This plasma differs in its properties from the discharge plasma, as has the track structure and low temperature of electrons, and the presence in gas mixtures of elec...
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Best Performance of n+ - p Crystalline Silicon Junction Solar Cells at 300 K, Due to the Effects of Heavy Doping and Impurity Size. I
Huynh Van Cong,
Paul Blaise,
Olivier Henri-Rousseau
Issue:
Volume 8, Issue 2, March 2019
Pages:
18-36
Received:
5 June 2019
Accepted:
10 July 2019
Published:
24 July 2019
Abstract: The effects of heavy doping and donor (acceptor) size on the hole (electron)-minority saturation current density JEo(JBo), injected respectively into the heavily (lightly) doped crystalline silicon (Si) emitter (base) region of n+ - p junction, which can be applied to determine the performance of solar cells, being strongly affected by the dark saturation current density: Jo≡JEo + JBo, were investigated. For that, we used an effective Gaussian donor-density profile to determine JEo, and an empirical method of two points to investigate the ideality factor n, short circuit current density Jsc, fill factor (FF), and photovoltaic conversion efficiency η, expressed as functions of the open circuit voltage Voc, giving rise to a satisfactory description of our obtained results, being compared also with other existing theoretical-and-experimental ones. So, in the completely transparent and heavily doped (P-Si) emitter region, CTHD(P-Si)ER, our obtained JEo-results were accurate within 1.78%. This accurate expression for JEo is thus imperative for continuing the performance improvement of solar cell systems. For example, in the physical conditions (PCs) of CTHD (P-Si) ER and of lightly doped (B-Si) base region, LD(B-Si)BR, we obtained the precisions of the order of 8.1% for Jsc, 7.1% for FF, and 5% for η, suggesting thus an accuracy of JBo (≤ 8.1%). Further, in the PCs of completely opaque and heavily doped (S-Si) emitter region, COHD(S-Si)ER, and of lightly doped (acceptor-Si) base region, LD(acceptor-Si)BR, our limiting η-results are equal to: 27.77%,…, 31.55%, according to the Egi-values equal to: 1.12eV ,…, 1.34eV, given in various (B,…, Tl)-Si base regions, respectively, being due to the acceptor-size effect. Furthermore, in the PCs of CTHD (donor-Si) ER and of LD(Tl-Si)BR, our maximal η-values are equal to: 24.28%,…, 31.51%, according to the Egi-values equal to: 1.11eV ,…, 1.70eV, given in various (Sb,…, S)-Si emitter regions, respectively, being due to the donor-size effect. It should be noted that these obtained highest η-values are found to be almost equal, as: 31.51%%≃31.55%, coming from the fact that the two obtained limiting J_o-values are almost the same.
Abstract: The effects of heavy doping and donor (acceptor) size on the hole (electron)-minority saturation current density JEo(JBo), injected respectively into the heavily (lightly) doped crystalline silicon (Si) emitter (base) region of n+ - p junction, which can be applied to determine the performance of solar cells, being strongly affected by the dark sat...
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