6 research outputs found
First results of dust injection in T-10 plasma
First results of T-10 injection experiments of the carbon dust particles with 2-10 mm diameter and 40-300 m/s velocity are presented. Different scenarios of the dust injection were tested. The dust particles ablation was studied. An approach for determination of a dust particle penetration length was developed. Measured penetration depths (3-7 cm) are compared with the simulation by the ablation model. The mm range of the separate dust particle diameters derived from the ablation data was close to sizes of the dust injected assuming that an acceleration of the separate particle is similar to the large carbon pellet in the pellet injector.ΠΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ΠΎ ΠΏΠ΅ΡΡΡ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΈ Π΅ΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΡΠ² ΠΏΠΎ ΡΠ½ΠΆΠ΅ΠΊΡΡΡ Π²ΡΠ³Π»Π΅ΡΠ΅Π²ΠΈΡ
ΠΏΠΈΠ»ΠΎΠ²ΠΈΡ
ΡΠ°ΡΡΠΎΠΊ Π΄ΡΠ°ΠΌΠ΅ΡΡΠΎΠΌ 2-10 ΠΌΠΊΠΌ Π·Ρ ΡΠ²ΠΈΠ΄ΠΊΠΎΡΡΡΠΌΠΈ 40-300 ΠΌ/Ρ Ρ Π’-10. ΠΡΠΎΡΠ΅ΡΡΠΎΠ²Π°Π½ΠΎ ΡΡΠ·Π½Ρ ΡΡΠ΅Π½Π°ΡΡΡ ΡΠ½ΠΆΠ΅ΠΊΡΡΡ ΠΏΠΈΠ»Ρ. ΠΠΎΡΠ»ΡΠ΄ΠΆΠ΅Π½ΠΎ Π²ΠΈΠΏΠ°Ρ ΠΏΠΈΠ»ΠΎΠ²ΠΈΡ
ΡΠ°ΡΡΠΎΠΊ. Π ΠΎΠ·ΡΠΎΠ±Π»Π΅Π½ΠΎ ΠΏΡΠΈΠ±Π»ΠΈΠ·Π½Ρ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΡ Π²ΠΈΠ·Π½Π°ΡΠ΅Π½Π½Ρ Π³Π»ΠΈΠ±ΠΈΠ½ΠΈ ΠΏΡΠΎΠ½ΠΈΠΊΠ½Π΅Π½Π½Ρ ΠΏΠΈΠ»ΠΎΠ²ΠΈΡ
ΡΠ°ΡΡΠΎΠΊ. ΠΠ±ΠΌΡΡΡΠ½Ρ Π³Π»ΠΈΠ±ΠΈΠ½ΠΈ ΠΏΡΠΎΠ½ΠΈΠΊΠ½Π΅Π½Π½Ρ (3-7 ΡΠΌ) ΠΏΠΎΡΡΠ²Π½ΡΠ²Π°Π»ΠΈΡΡ Π· ΡΠΎΠ·ΡΠ°Ρ
ΡΠ½ΠΊΠ°ΠΌΠΈ ΠΏΠΎ ΠΌΠΎΠ΄Π΅Π»Ρ Π²ΠΈΠΏΠ°ΡΡ. ΠΡΡΠ½Π΅Π½Ρ ΠΌΡΠΊΡΠΎΠ½Π½Ρ Π΄ΡΠ°ΠΌΠ΅ΡΡΠΈ ΡΠ°ΡΡΠΎΠΊ, ΠΎΡΡΠΈΠΌΠ°Π½Ρ Π· Π΄Π°Π½ΠΈΡ
ΠΏΠΎ Π²ΠΈΠΏΠ°ΡΡ, Ρ Π±Π»ΠΈΠ·ΡΠΊΠΈΠΌΠΈ Π΄ΠΎ ΡΠΎΠ·ΠΌΡΡΡΠ² ΡΠ½ΠΆΠ΅ΠΊΡΠΎΠ²Π°Π½ΠΎΠ³ΠΎ ΠΏΠΈΠ»Ρ, Ρ ΠΏΡΠΈΠΏΡΡΠ΅Π½Π½Ρ ΡΠΎΠ³ΠΎ, ΡΠΎ ΠΎΠΊΡΠ΅ΠΌΡ ΡΠ°ΡΡΠΊΠΈ ΠΏΡΠΈΡΠΊΠΎΡΡΡΡΡΡΡ ΡΠ°ΠΊ ΡΠ°ΠΌΠΎ, ΡΠΊ Ρ ΠΏΡΠΈ ΡΠ½ΠΆΠ΅ΠΊΡΡΡ Π²Π΅Π»ΠΈΠΊΠΈΡ
ΠΏΠ΅Π»Π΅ΡΡΠ².ΠΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Ρ ΠΏΠ΅ΡΠ²ΡΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠΎΠ² ΠΏΠΎ ΠΈΠ½ΠΆΠ΅ΠΊΡΠΈΠΈ ΡΠ³Π»Π΅ΡΠΎΠ΄Π½ΡΡ
ΠΏΡΠ»Π΅Π²ΡΡ
ΡΠ°ΡΡΠΈΡ Π΄ΠΈΠ°ΠΌΠ΅ΡΡΠΎΠΌ 2-10 ΠΌΠΊΠΌ ΡΠΎ ΡΠΊΠΎΡΠΎΡΡΡΠΌΠΈ 40-300 ΠΌ/Ρ Π² Π’-10. ΠΡΠΎΡΠ΅ΡΡΠΈΡΠΎΠ²Π°Π½Ρ ΡΠ°Π·Π»ΠΈΡΠ½ΡΠ΅ ΡΡΠ΅Π½Π°ΡΠΈΠΈ ΠΈΠ½ΠΆΠ΅ΠΊΡΠΈΠΈ ΠΏΡΠ»ΠΈ. ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΎ ΠΈΡΠΏΠ°ΡΠ΅Π½ΠΈΠ΅ ΠΏΡΠ»Π΅Π²ΡΡ
ΡΠ°ΡΡΠΈΡ. Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π° ΠΏΡΠΈΠ±Π»ΠΈΠ·ΠΈΡΠ΅Π»ΡΠ½Π°Ρ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ Π³Π»ΡΠ±ΠΈΠ½Ρ ΠΏΡΠΎΠ½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΡ ΠΏΡΠ»Π΅Π²ΡΡ
ΡΠ°ΡΡΠΈΡ. ΠΠ·ΠΌΠ΅ΡΠ΅Π½Π½ΡΠ΅ Π³Π»ΡΠ±ΠΈΠ½Ρ ΠΏΡΠΎΠ½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΡ (3-7 ΡΠΌ) ΡΡΠ°Π²Π½ΠΈΠ²Π°Π»ΠΈΡΡ Ρ ΡΠ°ΡΡΠ΅ΡΠ°ΠΌΠΈ ΠΏΠΎ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΠΈΡΠΏΠ°ΡΠ΅Π½ΠΈΡ. ΠΡΠ΅Π½Π΅Π½Π½ΡΠ΅ ΠΌΠΈΠΊΡΠΎΠ½Π½ΡΠ΅ Π΄ΠΈΠ°ΠΌΠ΅ΡΡΡ ΡΠ°ΡΡΠΈΡ, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΠ΅ ΠΈΠ· Π΄Π°Π½Π½ΡΡ
ΠΏΠΎ ΠΈΡΠΏΠ°ΡΠ΅Π½ΠΈΡ, Π±Π»ΠΈΠ·ΠΊΠΈ ΠΊ ΡΠ°Π·ΠΌΠ΅ΡΠ°ΠΌ ΠΈΠ½ΠΆΠ΅ΠΊΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΠΏΡΠ»ΠΈ, Π² ΠΏΡΠ΅Π΄ΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΠΈ ΡΠΎΠ³ΠΎ, ΡΡΠΎ ΠΎΡΠ΄Π΅Π»ΡΠ½ΡΠ΅ ΡΠ°ΡΡΠΈΡΡ ΡΡΠΊΠΎΡΡΡΡΡΡ ΡΠ°ΠΊ ΠΆΠ΅, ΠΊΠ°ΠΊ ΠΈ ΠΏΡΠΈ ΠΈΠ½ΠΆΠ΅ΠΊΡΠΈΠΈ ΠΊΡΡΠΏΠ½ΡΡ
ΠΏΠ΅Π»Π»Π΅ΡΠΎΠ²
Inverse magnetic catalysis in field theory and gauge-gravity duality
We investigate the surface of the chiral phase transition in the
three-dimensional parameter space of temperature, baryon chemical potential and
magnetic field in two different approaches, the field-theoretical
Nambu-Jona-Lasinio (NJL) model and the holographic Sakai-Sugimoto model. The
latter is a top-down approach to a gravity dual of QCD with an asymptotically
large number of colors and becomes, in a certain limit, dual to an NJL-like
model. Our main observation is that, at nonzero chemical potential, a magnetic
field can restore chiral symmetry, in apparent contrast to the phenomenon of
magnetic catalysis. This "inverse magnetic catalysis" occurs in the
Sakai-Sugimoto model and, for sufficiently large coupling, in the NJL model and
is related to the physics of the lowest Landau level. While in most parts our
discussion is a pedagogical review of previously published results, we include
new analytical results for the NJL approach and a thorough comparison of
inverse magnetic catalysis in the two approaches.Comment: 37 pages, 11 figures, to appear in Lect. Notes Phys. "Strongly
interacting matter in magnetic fields" (Springer), edited by D. Kharzeev, K.
Landsteiner, A. Schmitt, H.-U. Ye
Lattice QCD Simulations in External Background Fields
We discuss recent results and future prospects regarding the investigation,
by lattice simulations, of the non-perturbative properties of QCD and of its
phase diagram in presence of magnetic or chromomagnetic background fields.
After a brief introduction to the formulation of lattice QCD in presence of
external fields, we focus on studies regarding the effects of external fields
on chiral symmetry breaking, on its restoration at finite temperature and on
deconfinement. We conclude with a few comments regarding the effects of
electromagnetic background fields on gluodynamics.Comment: 31 pages, 10 figures, minor changes and references added. To appear
in Lect. Notes Phys. "Strongly interacting matter in magnetic fields"
(Springer), edited by D. Kharzeev, K. Landsteiner, A. Schmitt, H.-U. Ye
Magnetic Catalysis: A Review
We give an overview of the magnetic catalysis phenomenon. In the framework of
quantum field theory, magnetic catalysis is broadly defined as an enhancement
of dynamical symmetry breaking by an external magnetic field. We start from a
brief discussion of spontaneous symmetry breaking and the role of a magnetic
field in its a dynamics. This is followed by a detailed presentation of the
essential features of the phenomenon. In particular, we emphasize that the
dimensional reduction plays a profound role in the pairing dynamics in a
magnetic field. Using the general nature of underlying physics and its
robustness with respect to interaction types and model content, we argue that
magnetic catalysis is a universal and model-independent phenomenon. In support
of this claim, we show how magnetic catalysis is realized in various models
with short-range and long-range interactions. We argue that the general nature
of the phenomenon implies a wide range of potential applications: from certain
types of solid state systems to models in cosmology, particle and nuclear
physics. We finish the review with general remarks about magnetic catalysis and
an outlook for future research.Comment: 37 pages, to appear in Lect. Notes Phys. "Strongly interacting matter
in magnetic fields" (Springer), edited by D. Kharzeev, K. Landsteiner, A.
Schmitt, H.-U. Yee. Version 2: references adde
Conceptual design of pellet charge eXchange (PCX) diagnostics for stellarator W7-X
Pellet Charge eXchange diagnostic using Li pellets has been considered for the W7-X machine. Geometry of the experimental set-up and parameters of both lithium pellet injector (LPI) and neutral particle analyser (NPA) were evaluated. It was shown that this diagnostics can provide very well detectable H"0 signal in the range 50 - 1000 keV generated by RF driven H"+ minority ions in W7-X. The PCX diagnostics will be able to measure H"+ energy spectra and density profiles in wide range of W7-X plasma parameters. The proposed NPA can be designed on a basis of the NPA ISEP (Ioffe institute) installed now on JET. A pellet light-gas gun can be used to accelerate Li pellets of 2 - 3 mm in size up to 1 km/s velocities. That provides the required pellet penetration into the plasma core. Due to sticky problems with Li operation, a special technique of loading and keeping the pellets in a charger unit of LPI has to be developed. Development of PCX diagnostics for absolute measurements of the confined minority protons requires improvement of the pellet ablation model used. Knowledge of the cloud dimensions and density distributions of different charge states of ions is of special interest. It is necessary to improve predictions of pellet penetrations in non-Maxwellian plasmas as well. An optical system for measurements of pellet cloud density profiles should be foreseen on W7-X. (orig.)Available from TIB Hannover: RA 71(10/20) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman