Stimulated emission of Cr²⁺ ions in ZnS:Cr thin-film electroluminescent structures

First observation of stimulated Cr²⁺ emission in ZnS:Cr electroluminescent (EL) impact-excited thin-film waveguide structures is reported. The structures consist of the following thin films deposited on a glass substrate: a transparent In₂O₃:Sn electrode, an insulator SiO₂/Al₂O₃ layer (~270 nm), an EL ZnS:Cr film (~600 nm), the same insulator layer, and an Al electrode. The stimulated character of the emission recorded through the edge of the structure is evidenced by the following. With increasing the applied voltage, a broad band with three waveguide mode maxima in the edge emission spectrum changes into an intensifying and narrowing band. The maximum of this band is the same as that of the Cr²⁺ emission band recorded through the face, i.e. through the In₂O₃:Sn electrode (1.75 and ~2.6 µm at the Cr concentrations (5-7)*10¹⁹ and (2- 3)*10²⁰ cm⁻³, respectively). The five-fold narrowing is observed when increasing the voltage by ~4% in the case of the lower Cr concentration. The voltage and frequency dependences of the edge emission are stronger than those for the face emission. A small manifestation of the gain occurrence in the ZnS:Cr TFELS is also observed in the face emission. The possibility to create a new type of electrically pumped lasers with the impact excitation mechanism is discussed

Thermofield Cr→Cr²⁺ recharging resulting in anomalous intensification of Cr²⁺ emission in ZnS:Cr thin-film electroluminescent structures

For the first time, an anomalous strong increase of the Cr²⁺ emission intensity (I) with increasing the applied voltage (V) has been discovered in ZnS:Cr thin-film electroluminescent structures (TFELS) instead of the I(V) dependence saturation typical of TFELS of the MISIM type, where M is an electrode, I is an insulator layer and S is an EL film. The dependence of I on the transferred charge (Q) is very superlinear, whereas the luminance of the emission of hot electrons, which takes place simultaneously with the Cr²⁺ emission, increases proportionally to Q as it happens usually in TFELS. The increase of I and Q is accompanied by rising the sample temperature up to 30 – 50 °C. However, the emission spectrum that is inherent to the ⁵E → ⁵T₂ transition in the 3d shell of a Cr²⁺ ion is not changed in this case. The above effects are explained by Cr⁺ → Cr²⁺ thermofield recharging, which results in an increase of the number not only of free electrons, but also of Cr²⁺ radiation centers. The most probable mechanism of such a recharging is the Frenkel-Pool field-stimulated thermal ionization of Cr⁺ ions, whose ionization energy is 0.65…0.82 eV

Momentum relaxation of hot electrons during radiative intraband indirect transitions in ZnS:Cr

A structureless emission in the visible region was revealed in ZnS:Cr thin-film electroluminescent structures (TFELS) apart the main near-infrared emission resulted from the 5E → 5T2 transition in the 3d shell of the Cr²⁺ ion. This emission stems from intraband indirect transitions of hot electrons. The comparison between experimental intensity spectral dependence and the same dependence calculated for different mechanisms of the momentum relaxation shows that the scattering on charged impurities takes place during this emission. The Cr+ ions existing in ZnS:Cr in addition to predominant Cr²⁺ ions serve as scattering charge centers. This is confirmed by study of the magnetic field (H) effect on the intensity (I) of the hot electron emission at 4.2 K. The experimental dependence I(H) coincides with the calculated magnetic field dependence of the exchange scattering cross-section of Cr⁺ ion with the spin 5/2 and g-factor 2. This result also indicates that both the Coulomb interaction with Cr+ ions and the exchange scattering on them present during the hot electron emission in the ZnS:Cr TFELS

Laser oscillation in Cr²⁺:ZnS waveguide thin-film structures under electrical pumping with impact excitation mechanism

The laser oscillation at room temperature in Cr²⁺:ZnS waveguide thin-film structures under electrical pumping with the impact excitation mechanism was first discovered after improvement of some waveguide optical properties. However, lasing turned out to be unstable and ceases soon, which is accompanied by strong weakening the emission recorded from the waveguide edge whereas the emission from the structure face remains intensive. It is shown that the above changes stem from increasing optical losses caused by appearance of light scattering in the structure by inhomogeneities formed during lasing as a consequence the most probably of recrystallization processes in the Cr:ZnS film. Some ways are proposed to improve the lasing stabilit

Self-organization patterns in electroluminescence of bistable ZnS:Mn thin-film structures

An overview of recent original results concerning self-organized pattern formation in the emission of bistable alternating current ZnS:Mn thin - film electroluminescent structures (TFELS) as a dissipative system is given. The influence of technological factors, affecting the properties TFELS, and driving conditions on both the patterns and the hysteresis of the charge- voltage dependence that is responsible for bistability of the TFELS are considered. The correlation between patterns and the shape of the hysteresis is analyzed. The physical processes with positive and negative feedback, which serve, respectively, as activator and inhibitor in the given dissipative system, are discussed

On origin of rapid portion of luminance-voltage dependence of ZnS:Mn TFEL devices and its aging behavior

Some peculiarities in the rapid portion of the voltage dependences of luminance and transferred charge as well as in its aging behavior in ZnS:Mn thin film electroluminescent devices made by different deposition techniques have been revealed. The devices with nearly the same Mn concentration (~1 at. %) were deposited by electron-beam evaporation and two atomic-layer epitaxy processes based on chlorine (ZnCl₂, MnCl₂) or organic (diethyl Zn and Mn(thd)₃ ) precursors. It has been studied interrelation between these peculiarities and the differences observed in the photodepolarization spectra of the devices, which give data about defects in the ZnS:Mn films and the energy of corresponding local states in them. The obtained results are discussed as to physical processes responsible for the rapid portion of the above voltage dependences and for the causes of its change after short-time accelerated aging

Observation Of Very High Energy Cosmic-ray Families In Emulsion Chambers At High Mountain Altitudes (i)

Characteristics of cosmic-ray hadronic interactions in the 1015 - 1017 eV range are studied by observing a total of 429 cosmic-ray families of visible energy greater than 100 TeV found in emulsion chamber experiments at high mountain altitudes, Chacaltaya (5200 m above sea level) and the Pamirs (4300 m above sea level). Extensive comparisons were made with simulated families based on models so far proposed, concentrating on the relation between the observed family flux and the behaviour of high-energy showers in the families, hadronic and electromagnetic components. It is concluded that there must be global change in characteristics of hadronic interactions at around 1016 eV deviating from thise known in the accelerator energy range, specially in the forwardmost angular region of the collision. A detailed study of a new shower phenomenon of small-pT particle emissions, pT being of the order of 10 MeV/c, is carried out and its relation to the origin of huge "halo" phenomena associated with extremely high energy families is discussed as one of the possibilities. General characteristics of such super-families are surveyed. © 1992.3702365431Borisov, (1981) Nucl. Phys., 191 BBaybrina, (1984) Trudy FIAN 154, p. 1. , [in Russian], Nauka, MoscowLattes, Hadronic interactions of high energy cosmic-ray observed by emulsion chambers (1980) Physics Reports, 65, p. 151Hasegawa, ICR-Report-151-87-5 (1987) presented at FNAL CDF Seminar, , Inst. for Cosmic Ray Research, Univ. of TokyoCHACALTAYA Emulsion Chamber Experiment (1971) Progress of Theoretical Physics Supplement, 47, p. 1Yamashita, Ohsawa, Chinellato, (1984) Proc. 3rd Int. Symp. on Cosmic Rays and Particle Physics, p. 30. , Tokyo, 1984, Inst. for Cosmic Ray Research, Univ. of Tokyo(1984) Proc. 3rd Int. Symp. on Cosmic Rays and Particle Physics, p. 1. , Tokyo, 1984Baradzei, (1984) Proc. 3rd Int. Symp. on Cosmic Rays and Particle Physics, p. 136. , Tokyo, 1984Yamashita, (1985) J. Phys. Soc. Jpn., 54, p. 529Bolisov, (1984) Proc. 3rd Int. Symp. on Cosmic rays and Particle Physics, p. 248. , Tokyo, 1984, Inst. for Cosmic Ray Research, Univ. of TokyoTamada, Tomaszewski, (1988) Proc. 5th Int. Symp. on Very High Energy Cosmic-Ray Interactions, p. 324. , Lodz, 1988, Inst. for Cosmic Ray Research, Univ. of Tokyo, PolandHasegawa, (1989) ICR-Report-197-89-14, , Inst. for Cosmic Ray Research, Univ. of TokyoCHACALTAYA Emulsion Chamber Experiment (1971) Progress of Theoretical Physics Supplement, 47, p. 1Okamoto, Shibata, (1987) Nucl. Instrum. Methods, 257 A, p. 155Zhdanov, (1980) FIAN preprint no. 45, , Lebedev Physical Institute, MoscowSemba, Gross Features of Nuclear Interactions around 1015eV through Observation of Gamma Ray Families (1983) Progress of Theoretical Physics Supplement, 76, p. 111Nikolsky, (1975) Izv. Akad. Nauk. USSR Ser. Fis., 39, p. 1160Burner, Energy spectra of cosmic rays above 1 TeV per nucleon (1990) The Astrophysical Journal, 349, p. 25Takahashi, (1990) 6th Int. Symp. on Very High Energy Cosmic-ray Interactions, , Tarbes, FranceRen, (1988) Phys. Rev., 38 D, p. 1404Alner, The UA5 high energy simulation program (1987) Nuclear Physics B, 291 B, p. 445Bozzo, Measurement of the proton-antiproton total and elastic cross sections at the CERN SPS collider (1984) Physics Letters B, 147 B, p. 392Wrotniak, (1985) Proc. 19th Cosmic-Ray Conf. La Jolla, 1985, 6, p. 56. , NASA Conference Publication, Washington, D.CWrotniak, (1985) Proc. 19th Cosmic-Ray Conf. La Jolla, 1985, 6, p. 328. , NASA Conference Publication, Washington, D.CMukhamedshin, (1984) Trudy FIAN, 154, p. 142. , Nauka, Moscow, [in Russian]Dunaevsky, Pluta, Slavatinsky, (1988) Proc. 5th Int. Symp. on Very High Energy Cosmic-Ray Interactions, p. 143. , Lodz, 1988, Inst. of Physics, Univ. of Lodz, PolandKaidalov, Ter-Martirosyan, (1987) Proc. 20th Int. Cosmic-Ray Conf., Moscow, 1987, 5, p. 141. , Nauka, MoscowShabelsky, (1985) preprints LNPI-1113Shabelsky, (1986) preprints LNPI-1224, , Leningrad [in Russian]Hillas, (1979) Proc. 16th Int. Cosmic-Ray Conf., Kyoto, 6, p. 13. , Inst. for Cosmic Ray Research, Univ. of TokyoBorisov, (1987) Phys. Lett., 190 B, p. 226Hasegawa, Tamada, (1990) 6th Int. Symp. on Very High Energy Cosmic-Ray Interactions, , Tarbes, FranceSemba, Gross Features of Nuclear Interactions around 1015eV through Observation of Gamma Ray Families (1983) Progress of Theoretical Physics Supplement, p. 111Ren, (1988) Phys. Rev., 38 D, p. 1404Dynaevsky, Zimin, (1988) Proc. 5th Int. Symp. on Very High Energy Cosmic-Ray Interaction, p. 93. , Lodz, 1988, Inst. of Physics, Univ. of Lodz, PolandDynaevsky, (1990) Proc. 6th Int. Symp. on Very High Energy Cosmic-Ray Interactions, , Tarbes, France(1989) FIAN preprint no. 208, , Lebedev Physical Institute, Moscow(1990) Proc. 21st Int. Cosmic-Ray Conf., Adelaide, 8, p. 259. , Dept. Physics and Mathematical Physics, Univ. of Adelaide, AustraliaHasegawa, (1990) ICR-Report-216-90-9, , Inst. for Cosmic-Ray Research, Univ. of TokyoTamada, (1990) Proc. 21st Int. Cosmic-Ray Conf., Adelaide, 1990, 8. , Dept. Physics and Mathematical Physics, Univ. of Adelaide, AustraliaTamada, (1990) ICR-Report-216-90-9(1981) Proc. 17th Int. Cosmic-Ray Conf., Paris, 5, p. 291(1990) Proc. Int. Cosmic-Ray Conf., Adelaide, 1990, 8, p. 267. , Dept. Physics and Mathematical Physics, Univ. of Adelaide, Australia(1989) Inst. Nucl. Phys. 89-67/144, , preprint, Inst. Nucl. Phys., Moscow State UnivSmilnova, (1988) Proc. 5th Int. Sym. on Very High Energy Cosmic-Ray Interactions, p. 42. , Lodz, 1988, Inst. of Physics, Univ. of Lodz, PolandGoulianos, (1986) Proc. Workshop of Particle Simulation at High Energies, , University of Wisconsin, Madison, USAIvanenko, (1983) Proc. 18th Int. Cosmic-Ray Conf., Bangalore, 1983, 5, p. 274. , Tata Inst. Fundamental Research, Bombay, IndiaIvanenko, (1984) Proc. Int. Symp. on Cosmic-Rays and Particle Physics, p. 101. , Tokyo, 1984, Inst. for Cosmic Ray Research, Univ. of Tokyo(1988) 5th Int. Symp. on Very High Energy Cosmic-Ray Interactions, p. 180. , Lodz, 1988, Inst. of Physics, Univ. of Lodz, Poland(1990) Proc. 21st Int. Cosmic-Ray Conf., Adelaide, 1990, 8, p. 251. , Dept. Physics and Mathematical Physics, Univ. of Adelaide, Australia(1991) Izv. AN USSR No. 4, , to be publishedNikolsky, Shaulov, Cherdyntseva, (1990) FIAN preprint no. 140, , Lebedev Physical Institute, Moscow, [in Russian](1987) Proc. 20th Int. Cosmic-Ray Conf., Moscow, 1987, 5, p. 326. , Nauka, Mosco

Observation Of A High-energy Cosmic-ray Family Caused By A Centauro-type Nuclear Interaction In The Joint Emulsion Chamber Experiment At The Pamirs

An exotic cosmic-ray family event is observed in the large emulsion chamber exposed by the joint at the Pamirs (4360 m above sea level). The family is composed of 120γ-ray-induced showers and 37 hadron-induced showers with individual visible energy exceeding 1 TeV. The decisive feature of the event is the hadron dominance: ΣEγ, ΣE(γ) h, 〈Eγ, 〈E(γ) h〉, 〈Eγ·Rγ〉 and 〈E(γ)·Rh〉 being 298 TeV, 476 TeV, 2.5 TeV, 12.9 TeV, 28.6 GeV m and 173 GeV m, respectively. Most probably the event is due to a Centauro interaction, which occured in the atmosphere at ∼700 m above the chamber. The event will constitute the second beautiful candidate for a Centauro observed at the Pamirs. © 1987.1901-2226233Bayburina, (1981) Nucl. Phys. B, 191, p. 1Lattes, Fujimoto, Hasegawa, Hadronic interactions of high energy cosmic-ray observed by emulsion chambers (1980) Physics Reports, 65, p. 151(1984) Trudy FIAN, 154, p. 1Borisov, (1984) Proc. Intern. Symp. on Cosmic rays and particle physics, p. 3. , TokyoRen, (1985) 19th Intern. Cosmic ray Conf., 6, p. 317. , La JollaYamashita, (1985) 19th Intern. Cosmic ray Conf., 6, p. 364. , La JollaTamada, (1977) Nuovo Cimento, 41 B, p. 245T. Shibata et al., to be publishedHillas, (1979) 16th Intern. Cosmic ray Conf., 6, p. 13. , KyotoBattiston, Measurement of the proton-antiproton elastic and total cross section at a centre-of-mass energy of 540 GeV (1982) Physics Letters B, 117, p. 126UA5 Collab., G.J. Alner et al., preprint CERN-EP/85-62Taylor, (1976) Phys. Rev. D, 14, p. 1217Burnett, (1984) Proc. Intern. Symp. on Cosmic rays and particle physics, p. 468. , Toky

Nuclear Interactions Of Super High Energy Cosmic-rays Observed In Mountain Emulsion Chambers

Here we present a summary of joint discussions on the results of three mountain experiments with large-scale emulsion chambers, at Pamir, Mt. Fuji and Chacaltaya. Observations cover gamma quanta, hadrons and their clusters (called "families"). The following topics are covered, concerning the characteristics of nuclear interactions the energy region 1014-1016 eV: (i) rapid dissipation seen in atmospheric diffusion of high-energy cosmic-rays; (ii) multiplicity and Pt increase in produced pi-mesons in the fragmentation region; (iii) existence of large-Pt jets, (iv) extremely hadron-rich family of the Centauro type; (v) exotic phenomena in the extremely high energy region beyond 1016 eV. © 1981.1911125(1977) Acta Univ. Lodz ser. II, (60)(1973) 13th Int. Cosmic-ray Conf., 3, p. 2228(1975) 14th Int. Cosmic-Ray Conf., 7, p. 2365(1979) AIP Conf. Proc. no. 49, p. 334(1979) 16th Int. Cosmic-ray Conf., 6, p. 344(1979) 16th Int. Cosmic-ray Conf., 7, p. 6816th Int. Cosmic-ray Conf. (1979) 16th Int. Cosmic-ray Conf., 7, p. 284(1979) 16th Int. Cosmic-ray Conf., 7, p. 294(1979) 16th Int. Cosmic-ray Conf., 13, p. 87(1979) 16th Int. Cosmic-ray Conf., 13, p. 92(1979) 16th Int. Cosmic-ray Conf., 13, p. 98(1979) AIP Conf. Proc. no. 49, p. 94(1979) AIP Conf. Proc. no. 49, p. 145(1979) AIP Conf. Proc. no. 49, p. 317(1979) 16th Int. Cosmic-ray Conf., 6, p. 350(1979) 16th Int. Cosmic-ray Conf., 6, p. 356(1979) 16th Int. Cosmic-ray Conf., 6, p. 362Nikolsky, Proc. 9th Int. High-energy Symp. (1978) CSSR, 21. , ToborMiyake, (1978) Proc. 19th Int. Conf. on High-energy physics, p. 433Vernov, (1977) Physica, 3, p. 1601Khristiansen, (1978) JETP Lett., 28, p. 124(1973) 13th Int. Cosmic-ray Conf., 3, p. 2219Izv. Acad. Nauk USSR, ser Phys. (1974) Izv. Acad. Nauk USSR, ser Phys., 38, p. 918(1975) 14th Int. Cosmic-ray Conf., 7, p. 2365(1979) 16th Int. Cosmic-ray Conf., 7, p. 68Dunaevsky, Urysson, Emelyanov, Shorin, Tashimov, (1975) FIAN preprint no. 150Dunaevsky, Urysson, Emelyanov, Shorin, Tashinov, (1979) Acta Univ. Lodz ser. II, (60), p. 199Ivanenko, Kanevskya, Roganova, (1978) JETP Lett., 40, p. 704Ivanenko, Kanevsky, Roganova, (1979) 16th Int. Cosmic-ray Conf., 7, p. 101Ivanenko, Kanevsky, Roganova, (1979) 16th Int. Cosmic-ray Conf., 7, p. 198Wrotniak, (1977) Acta Univ. Lodz ser. II, (60), p. 165Krys, Tomaszevski, Wrotniak, (1979) 16th Int. Cosmic-ray Conf., 7, p. 182Krys, Tomaszevski, Wrotniak, (1979) 16th Int. Cosmic-ray Conf., 7, p. 186Fomin, Kempa, Khristiansen, Levina, Piotrowska, Wdowczyk, (1977) 15th Int. Cosmic-ray Conf., 7, p. 248Fomin, Kempa, Khristiansen, Levina, Piotrowska, Wdowczyk, (1979) 16th Int. Cosmic-ray Conf., 13, p. 82Azimov, Mullazhanov, Yuldashbayev, (1979) 16th Int. Cosmic-ray Conf., 7, p. 262Azimov, Mullazhanov, Yuldashbayev, (1977) Acta Univ. Lodz ser. II, (60), p. 275Kasahara, Torri, Yuda, (1979) 16th Int. Cosmic-ray Conf., 13, p. 70Kasahara, Torii, Yuda, (1979) 16th Int. Cosmic-ray Conf., 13, p. 79Shibata, (1979) 16th Int. Cosmic-ray Conf., 7, p. 176H. Semba, T. Shibata and T. Tabuki, Suppl. Prog. Theor. Phys., to be publishedZhdanov, Roinishvilli, Smorodin, Tomaszevski, (1975) FIAN preprint no. 163Lattes, Fujimoto, Hasegawa, Hadronic interactions of high energy cosmic-ray observed by emulsion chambers (1980) Physics Reports, 65, p. 152Ellsworth, Gaisser, Yodh, (1981) Phys. Rev., 23 D, p. 764Baradzei, Smorodin, (1974) FIAN preprint nos. 103, 104Baradzei, Smorodin, (1977) Acta Univ. Lodz ser. II, (60), p. 51Zhdanov, (1980) FIAN preprint no. 140H. Semba, T. Shibata and T. Tabuki, Suppl. Prog. Theor. Phys., to be publishedShibata, (1980) Phys. Rev., 22 D, p. 100Slavatinsky, (1980) Proc. 7th European Symp. on Cosmic rays, , Leningrad, to be published(1979) AIP Conference Proc. no. 49, p. 145Azimov, Abduzhamilov, Chudakov, (1963) JETP (Sov. Phys.), 45, p. 40713th Int. Cosmic-ray Conf. (1973) 13th Int. Cosmic-ray Conf., 5, p. 326Acharya, Rao, Sivaprasad, Rao, (1979) 16th Int. Cosmic-ray Conf., 6, p. 289Ellsworth, Goodman, Yodh, Gaisser, Stanev, (1981) Phys. Rev., 23 D, p. 771Bariburina, Guseva, Denisova, (1980) Acta Univ. Lodz, 1, p. 9415th Int. Cosmic-ray Conf. (1977) 15th Int. Cosmic-ray Conf., 7, p. 184(1979) AIP Conf. Proc. no. 49, p. 33

RESULTS OF AN OPEN, MONOCENTERED NON-RANDOMISED, WITHOUT CONTROL GROUP, OBSERVATIONAL QUALITY OF LIFE EVALUATION STUDY IN PATIENTS WITH IDIOPATHIC JUVENILE ARTHRITIS TREATED WITH ETARNECEPT IN COMBINATION WITH METHOTREXATE

Study objective — to evaluate etarnecept influence on quality of life of idiopathic juvenile arthritis patients’ quality of life. 25 patients with poly- and oligoarthritides aged 8 (6; 11) years. Before etarnecept use quality of life of all patients was significantly lower that that of healthy children judging upon children’s own opinion and that of their parents. No longer that after 1 month since the beginning of etarnecept treatment 92% of patients claimed significant increase in their quality of life (according to patients’ opinion, total score increase from 53 to 59, from 49 to 60, according to parents (p < 0,001). After 12 months of treatment 68 % of patients had quality of life similar to the one of healthy children.Key words: juvenile idiopathic arthritis, etarnecept, methotrexate, quality of life, efficacy, safety. (Voprosy sovremennoi pediatrii — Current Pediatrics. — 2011; 10 (6): 26–34.