Alignment in Gamma-Hadron Families of Cosmic Rays

Alignment of main fluxes of energy in a target plane is found in families of cosmic ray particles detected in deep lead X-ray chambers. The fraction of events with alignment is unexpectedly large for families with high energy and large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in interaction of particles with superhigh energy, $E_0 > 10^{16}$ eV. Data analysis suggests that production of most aligned groups occurs low above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region. The most elaborated hypothesis for explanation of alignment is related to the quark-gluon string rupture. However, the problem of theoretical interpretation of our results still remains open.Comment: 15 pages, 2 tables, 6 figures (not included), Stanford University preprint SU-ITP-94-2

Influence of plasma with finite pressure on magnetic configuration of torsatron U-3M

Series of experiments on generation of mode with high β (up to about 1.3%) in torsatron U-3M were performed using nitrogen as working gas. The dependence of average β from input power was obtained. The average plasma radii in modes with various β were determined. The estimation of rotational transformation angle was done in view of presence of the plasma in device.На торсатроні У-3М проведено серію експериментів по створенню режиму з високим β (до 1.3%) з використанням азоту в якості робочого газу. Отримано залежність середнього β від потужності, що вводиться. Було визначено середній радіус плазми в режимах з різним β. Оцінка кута обертального перетворення була зроблена з урахуванням наявності плазми в установці.На торсатроне У-3М проведена серия экспериментов по созданию режима с высоким β (до 1.3%) с использованием азота в качестве рабочего газа. Получена зависимость среднего β от вводимой мощности. Был определён средний радиус плазмы в режимах с различным β. Оценка угла врщательного преобразования была сделана с учетом наличия плазмы в установк

Euler-Calogero-Moser system from SU(2) Yang-Mills theory

The relation between SU(2) Yang-Mills mechanics, originated from the 4-dimensional SU(2) Yang-Mills theory under the supposition of spatial homogeneity of the gauge fields, and the Euler-Calogero-Moser model is discussed in the framework of Hamiltonian reduction. Two kinds of reductions of the degrees of freedom are considered: due to the gauge invariance and due to the discrete symmetry. In the former case, it is shown that after elimination of the gauge degrees of freedom from the SU(2) Yang-Mills mechanics the resulting unconstrained system represents the ID_3 Euler-Calogero-Moser model with an external fourth-order potential. Whereas in the latter, the IA_6 Euler-Calogero-Moser model embedded in an external potential is derived whose projection onto the invariant submanifold through the discrete symmetry coincides again with the SU(2) Yang-Mills mechanics. Based on this connection, the equations of motion of the SU(2) Yang-Mills mechanics in the limit of the zero coupling constant are presented in the Lax form.Comment: Revtex, 14 pages, no figures. Abstract changed, strata analysis have been included, typos corrected, references adde

Energy confinement in the torsatron Uragan-3M during the RF-heating mode

Energy confinement time of plasma in torsatron U-3M was measured both during quasi-stationary stady of RF-discharge and after RF-power cut-off. Power absorbed by plasma in the confinement region was estimated. A mechanism which explain the plasma density behavior in the confinement region is proposed.Експериментально визначено енергетичний час життя плазми під час квазістаціонарної стадії ВЧ-розряду і при вимкненні ВЧ-розряду в торсатроні У-3М. Оцінена частка потужності, що випромінюється ВЧ-антеною, яка поглинається плазмою в області її утримання. Запропоновано можливий механізм, що пояснює поведінку щільності плазми в області утримання.Экспериментально определено энергетическое время жизни плазмы во время квазистационарной стадии ВЧ- разряда и при выключении ВЧ-разряда в торсатроне У­-3М. Оценена доля мощности, излучаемой ВЧ-антенной, которая поглощается плазмой в области ее удержания. Предложен возможный механизм, объясняющий поведение плотности плазмы в области удержания

Electromagnetic oscillations at the edge of the Uragan-3M plasma

In the Uragan-3M torsatron the plasma is ICRF heated with the use of antennas of different types. The objective of this work is to study the electromagnetic wave propagation outside the plasma confinement volume and the effect of these waves on confined plasma behavior during RF-heating.В торсатроне Ураган-3М плазма нагревается ВЧ-волнами вблизи ионно-циклотронного резонанса антеннами различных типов. Целью настоящей работы является изучение распространения электромагнитных волн вне объема удержания и влияния этих волн на параметры плазмы в течение разряда.У торсатроні Ураган-3М плазма нагрівається ВЧ-хвилями поблизу іонного-циклотронного резонансу антенами різних типів. Метою цієї роботи є вивчення поширення електромагнітних хвиль поза обсягу утримання і впливу цих хвиль на параметри плазми протягом розряду

Density and potential fluctuations in the edge plasma of the Uragan-3m torsatron

Ion saturation current and floating potential fluctuations are recorded by movable array of 4 Langmuir probes near the boundary of the confinement region in the l = 3/m = 9 Uragan-3M torsatron with an RF produced and heated plasma. On the basis of these data main spectral and time characteristics of the low frequency electrostatic turbulence have been derived. The existence of the radial electric field shear and reversal of poloidal phase velocity of the fluctuations at the plasma boundary have been confirmed. The time function of the turbulent E×B particle flux contains intermittent bursts with the amplitude multiply exceeding the average flux. Up to 70% of the total fluctuating flux is carried in these bursts

Divertor flow and particle loss behaviors in spontaneous change of confinement state in the URAGAN-3M torsatron

Under conditions of spontaneous change of plasma confinement state having been observed recently in the U-3M torsatron with a natural helical divertor, it is shown that at the initial phase of this change all the components of the diverted plasma flow (DPF) decrease, while thermal (TI) and suprathermal (STI) ion content in the bulk plasma increases and the TI+STI fraction in the DPF is reduced on the ion В×∇В drift side, thus indicating an improvement of ion confinement. The initial phase is ended by a DPF rise on the ion В×∇В drift side, a TI+STI content decay in the bulk plasma and a rise of TI+STI outflow into the DPF, these being indications of an ion confinement deterioration. However, a simultaneous DPF reduction on the electron В×∇В drift side and a rise of electron density and ECE indicate an improvement of electron confinement.В умовах виявленої раніше спонтанної зміни режиму утримання в торсатроні У-3М з природним гвинтовим дивертором показано, що на початковій стадії цієї зміни зменшуються всі складові плазмового диверторного потоку (ПДП), в той час, як зростає кількість теплових (ТІ) та надтеплових (НТІ) іонів в основній плазмі, засвідчуючи про покращення їх утримання. Початкова стадія завершується зростанням ПДП на боці іонного дрейфу В×∇В, зменшенням кількості ТІ та НТІ в основній плазмі та підвищеним виходом їх до ПДП, що є ознакою погіршення утримання іонів. Але одночасне зменшення ПДП на боці електронного дрейфу В×∇В і зростання електронної густини та електронного циклотронного випромінювання вказують на покращення утримання електронів.В условиях обнаруженного ранее спонтанного изменения режима удержания в торсатроне У-3М с естественным винтовым дивертором показано, что на начальной стадии этого изменения уменьшаются все составляющие плазменного диверторного потока (ПДП) и растёт содержание тепловых (ТИ) и сверхтепловых (СТИ) ионов в основной плазме, свидетельствуя об улучшении их удержания. Начальная стадия завершается возрастанием ПДП на стороне ионного дрейфа В×∇В, уменьшением содержания ТИ и СТИ в основной плазме и повышенным их уходом в ПДП, что говорит об ухудшении удержания ионов. Однако, при этом уменьшается ПДП на стороне электронного дрейфа В×∇В и растут плотность электронов и электронное циклотронное излучение, что указывает на улучшение удержания электронов

Effects of plasma heating on the magnitude and distribution of plasma flows in the helical divertor of the Uragan-3M torsatron

Recently, a strong up-down asymmetry in the poloidal distributions of diverted plasma flows has been observed in the l = 3/m = 9 Uragan-3M torsatron, in many features similar to what have been observed in the l = 2 Heliotron E heliotron/torsatron. With this asymmetry, the predominant outflow of the diverted plasma is directed with the ion toroidal drift. On this basis, the asymmetry can be related to the space non-uniformity of the charged particle loss. In the work reported, the magnitude of divertor flow in U-3M and the vertical asymmetry in its distribution are studied as functions of the heating parameter P/, P being the power absorbed in the plasma, and are juxtaposed with corresponding P-related changes in the density and fast ion content in the plasma. As P/ increases, an increase of fast ion content and of particle loss, on the one hand, and an increase of divertor flow magnitude and of vertical asymmetry of the flow, on the other hand, are observed. A mutual accordance between these processes validates the hypothesis on a dominating role of fast particle loss in formation of vertical asymmetry of divertor flows in helical devices

Transition to the improved confinement mode in torsatron U-3M in range of rare collision frequencies

Transition to the mode of improved plasma confinement in U-3M facility earlier was discussed in works [1-3]. In these studies discussed the various processes in the confinement volume and in the peripheral plasma that accompany the transition process. Study of plasma confinement and process of transition into the mode of improved confinement just at rare collisions between plasma particles is very important because future fusion reactor based on a toroidal magnetic trap will operate under plasma parameters with rare collision frequencies (“banana” mode). The peculiarity of experiments on torsatron U-3M is that they are conducted at small density ne ≤ 2×10^12 cm^-3 and, thereby, the frequency of collisions in the confinement area is in the "banana" mode [4]. And herewith, time of collisions is essentially smaller (up to several orders for electrons and up to the order for ions) than the lifetime of plasma particles. It ensures maxwellization of distribution function and possibility to compare the obtained results with data from other experiments. The objective of this work is to study the main regularity of transition into the mode of improved confinement. Also it is interesting to compare the results with data from other facilities

Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at sNN=200\sqrt{s_{NN}} = 200 GeV

Identified mid-rapidity particle spectra of $\pi^{\pm}$, $K^{\pm}$, and $p(\bar{p})$ from 200 GeV p+p and d+Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor ($R_{dAu}$) between protons $(p+\bar{p})$ and charged hadrons ($h$) in the transverse momentum range $1.2<{p_{T}}<3.0$ GeV/c is measured to be $1.19\pm0.05$(stat)$\pm0.03$(syst) in minimum-bias collisions and shows little centrality dependence. The yield ratio of $(p+\bar{p})/h$ in minimum-bias d+Au collisions is found to be a factor of 2 lower than that in Au+Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC.Comment: 6 pages, 4 figures, 1 table. We extended the pion spectra from transverse momentum 1.8 GeV/c to 3. GeV/