Plasma heating and confinementat the GOL-3-II facility

Results of experiments on plasma heating and confinement in multimirror open trap GOL-3-II are presented. This facility is intended for heating and confinement of a relatively dense (10¹⁵-10¹⁷ cm⁻³) plasma in axially-symmetrical magnetic system. The plasma heating is provided by a high-power electron beam (1 MeV, 30 kA, 8 µs, 200 kJ). Results of the experiments with multimirror configuration of the device indicate that the confinement time of the plasma with ne ~ (0,5÷5).10¹⁵ cm⁻³ and Te ~1 keV increases more than order of magnitude in comparison with single mirror device

Plasma heating and confinement in the GOL-3 multiple mirror trap

Experiments on plasma confinement in a multiple mirror configuration are carried out at GOL-3 facility in Novosibirsk. Feature of experiments at this facility is high plasma density (up to 5⋅10²¹ m⁻³ ). High ion temperature (up to 2 keV) essentially differs the regime with multimirror configuration from previously studied plasma heating by the Ebeam in a uniform magnetic field. Physical mechanism of effective heating of plasma ions, substantially dependent on corrugation of the magnetic field is discussed. In this paper the new experimental data from the GOL-3 facility are presented and the main attention to a stage of ion heating is addressed.Експерименти по нагріванню й утриманню плазми в багатопробковій пастці проводяться на установці ГОЛ- 3 у Новосибірську. Особливістю плазми в цій пастці є її відносно висока (до 5⋅10²¹ м⁻³ ) густина. Нагрівання плазми релятивістським електронним пучком у багатопробковій пастці істотно відрізняється від нагрівання в простому соленоїді тим, що спостерігається збільшення іонної температури аж до 2 кэВ. У роботі обговорюється механізм швидкого нагрівання іонів і представляються нові експериментальні результати, отримані на установці ГОЛ-3.Эксперименты по нагреву и удержанию плазмы в многопробочной ловушке проводятся на установке ГОЛ-3 в Новосибирске. Особенностью плазмы в этой ловушке является ее относительно высокая (до 5⋅10²¹ м⁻³ ) плотность. Нагрев плазмы релятивистским электронным пучком в многопробочной ловушке существенно отличается от нагрева в простом соленоиде тем, что наблюдается увеличение ионной температуры вплоть до 2 кэВ. В работе обсуждается механизм быстрого нагрева ионов и представляются новые экспериментальные результаты, полученные на установке ГОЛ-3

The results of using micropulse cyclophotocoagulation for the treatment of patients with primary open-angle glaucoma

V.V. Egorov1,2, A.V. Postupaev1, N.V. Postupaeva1 1Khabarovsk Branch of the S. Fedorov Eye Microsurgery Federal State Institution, Khabarovsk, Russian Federation 2Institute of Advanced Training of Healthcare Specialists, Khabarovsk, Russian Federation Aim: to evaluate the clinical efficacy and safety of using micropulse cyclophotocoagulation (MP-CPC) for the treatment patients with mild and moderate stages of primary open-angle glaucoma (POAG). Patients and Methods: the clinical study included 56 patients (62 eyes) with POAG, 49–82 years old. The mild stage of glaucoma was detected in 33 eyes and the moderate stage — in 29 eyes. The level of intraocular pressure (IOP) before surgery ranged from 25 to 38 mm Hg (mean 29.2±2.8 mm Hg). All patients underwent MP-CPC according to the standard technique with the use of the Cyclo G6 Glaucoma Laser System and the MicroPulse P3 probe (IRIDEX, USA). The follow-up period was 6 months. Results: no complications were reported after the surgeries. The mean level of intraocular pressure at day 1 after surgery was 21.7±1.9 mm Hg. A gradual intraocular pressure decrease was recorded by the third week after the surgical treatment, and its stabilization to 17.9±1.9 mm Hg occurred by the sixth month of observation in 94% of the eyes. At day 1 after the surgery, the reduction of intraocular pressure was more pronounced in patients with dark (brown) color of the iris in comparison with patients who had light (blue) color of the iris. It was found that up to 6 months after the surgery, the group of patients under 60 years of age had a more noticeable postoperative hypotensive effect when compared to the patient group over 71 years. Conclusion: MP-CPC was an effective and safe operation for normalizing intraocular pressure in most of the patients with mild to moderate stages of POAG during the 6-month follow-up period. Considering the minimization of the surgical trauma, MP-CPC can prolong the hypotensive effect and preserve visual functions in patients with mild to moderate stages of glaucoma in the near-term future (up to 6 months) after the surgical treatment. Keywords: micropulse cyclophotocoagulation, primary open-angle glaucoma, mild stage, moderate stage, intraocular pressure. For citation: Egorov V.V., Postupaev A.V., Postupaeva N.V. The results of using micropulse cyclophotocoagulation for the treatment of patients with primary open-angle glaucoma. Russian Journal of Clinical Ophthalmology. 2022;22(4):204–209 (in Russ.). DOI: 10.32364/2311-7729-2022-22-4-204-209. </p

Blistering of the selected materials irradiated by intense 200keV proton beam

Formation of blisters on the surfaces of metal targets made of the selected materials was studied. The targets were irradiated by 100-200 keV, 1-2 mA proton beam up to the doses above 10/sup 24/ m/sup -2/. Real-time monitoring of the target surface was performed with a set of in situ optical surface diagnostics that allows detection of the moment of blisters appearance. The overview of experimental setup and the results of testing of different materials are presented. The number and the size of blisters gradually increase during the irradiation. Critical fluence of blistering strongly depends on the target temperature, proton energy and surface machining method. The features of blistering under the proton beam irradiation and the effects of hydrogen diffusion and interaction with the target lattice are discussed. [All rights reserved Elsevier].Anglai

Calculation of Cracking inTungsten Manufactured According to ITER Specifications Under Pulsed Heat Load

A mathematical model of surface cracking under pulsed heat load was developed. The model correctly describes a smooth brittle–ductile transition. The elastic deformation is described in a thin-heated-layer approximation. The plastic deformation is described with the Hollomon equation. The time dependence of the deformation and stresses is described for one heating–cooling cycle for a material without initial plastic deformation.The model can be applied to tungsten manufactured according to ITER specifications. The model shows that the stability of stress-relieved tungsten deteriorates when the base temperature increases. This proved to be a result of the close ultimate tensile and yield strengths. For a heat load of arbitrary magnitude a stability criterion was obtained in the form of condition on the relation of the ultimate tensile and yield strengths