Proceedings of USSR-Japan Joint Seminar on Plasma Diagnostics
Table of Contents
PDF Download Full Paper (v4)
Version History
v4 Current v2 Archived v1 Original
← Back to Investigations

Proceedings of USSR-Japan Joint Seminar on Plasma Diagnostics

Summary

This research report compiles the proceedings of the USSR-Japan Joint Seminar on Plasma Diagnostics held at Nagoya University in November 1979. It contains reports and research papers detailing advanced plasma diagnostics methodologies, high-temperature fusion plasma instrumentation, and diagnostic systems designed for large-scale devices including JT-60, T-15, Heliotron-E, and JIPP T-II.

Title Page - IPPJ-438

INSTITUTE OF PLASMA PHYSICS NAGOYA UNIVERSITY

Proceedings of USSR-Japan Joint Seminar on Plasma Diagnostics Nov. 13, 1979 through Nov. 17, 1979 Institute of Plasma Physics, Nagoya Univ. (Received Jan. 10, 1980) IPPJ-438 Jan. 1980

RESEARCH REPORT NAGOYA, JAPAN

Publication Information

Proceedings of USSR-Japan Joint Seminar on Plasma Diagnostics Nov. 13, 1979 through Nov. 17, 1979 Institute of Plasma Physics, Nagoya Univ. (Received Jan. 10, 1980) IPPJ-438 Jan. 1980

Further communication about this report is to be sent to the Research Information Center, Institute of Plasma Physics, Nagoya University, Nagoya 464, Japan.

Preface

PREFACE

USSR-Japan Joint Seminar on Plasma Diagnostics was held on November 13 through 16, 1979, at the Institute of Plasma Physics, Nagoya University. At this seminar, the following topics were discussed; development of high temperature plasma diagnostics suitable for nuclear fusion research; diagnostics for large tokamaks JT-60 and T-15 which are under construction in Japan and USSR, respectively; diagnostic results recently obtained in several experimental devices.

Through the discussion on these topics, we recognized the achievements in both countries and could find out the basic direction of the research in this field.

This preprint contains the reports orally presented at the seminar. Therefore, detailed descriptions might be missing, or preliminary results are included in some case.

It is requested not to reproduce or transmit any part of this preprint without the consent of the authors.

O. Pavlichenko J. Fujita

Contents

CONTENTS

A1 Status of JT-60 Diagnostics Y. Suzuki — 1

A2 Diagnostic Complex of T-15 D. V. Orlinskii, presented by A. Stefanovsky — 9

A3 Diagnostics in Heliotron-E Heliotron E Group — 22

A4 Works on Plasma Diagnostics in KhPTI O. S. Pavlichenko and V. I. Tereshin — 27

A5 Plasma Diagnostics on JIPP T-II Stellarator/Tokamak J. Fujita — 36

A6 Plasma Diagnostics in Tokamaks on Emission and Scattering of Electromagnetic Waves V. V. Rozhdestvensky — 50

A7 Measurements of Nonstationary and Anisotropic Density Fluctuations Using Electromagnetic Wave Scattering T. Tsukishima, O. Asada, K. Yoshioka and A. Inoue — 75

A8 A Twin Optically-Pumped Far-Infrared CH3OH Laser for the Large Tokamak Plasma Diagnostics M. Yamanaka, Y. Takeda, S. Tanigawa, A. Nishizawa, N. Noda, J. Fujita, M. Takai, M. Shimobayashi, Y. Hayashi, T. Koizumi, K. Nagasaka, S. Okajima, Y. Tsunawaki and A. Nagashima — 81

A9 Development of SMM Wave Laser Scattering Apparatus for the Measurements of Waves and Turbulences in the Tokamak Plasma T. Saito, Y. Hamada, T. Yamashita, M. Ikeda, M. Nakamura and S. Tanaka — 86

B2 Methods of Determining the Elongation Ratio in a Non-circular Tokamak S. Shinohara and Miyamoto-Toyama Group — 92

B3 Experimental Investigation of Circular and Elliptic Plasma Column in TORIUT-4 M. Kikuchi, N. Inoue, M. Mori, K. Moriya, K. Miyata, K. Okano and T. Uchida — 98

B4 Feedback Control of Plasma Position in JIPP T-II S. Itoh, K. Toi and K. Matsuura — 105

B5-a Control of Horizontal Plasma Position by Feedforward-Feedback System with Digital Computer in JIPP T-II Tokamak K. Toi, K. Sakurai, S. Itoh, K. Matsuura and S. Tanahashi — 109

B5-b Confinement of Ohmic- and Turbulent-Heated Plasmas in Small High-Field Tokamak TRIAM-1 K. Toi, S. Itoh, Y. Kawai, N. Hiraki, K. Nakamura and O. Mitarai — 115

C1 Poloidal Divertor Experiment in DIVA/JFT-2a DIVA Group presented by Y. Shimomura — 121

C4 Role of Impurity Spectra in Tokamak Plasmas K. Mori — 128

D1 Some Optical Diagnostics for the Plasma Focus V. M. Korzhavin — 137

D2 Diagnostics of Dense Plasma Focus by Ruby Laser Holography M. Yokoyama, Y. Kitagawa, I. Tsuda, Y. Yamada and A. Ishizaki — 162

D3 Interferogram Processing by Help of a Computer D. B. Lazebnik, A. P. Petrov and S. S. Tserevitinov — 170

E1 Plasma Diagnostics for GAMMA-6 Experiment K. Ishii, T. Kawabe and S. Miyoshi — 179

E2 Heavy Ion Beam Probe for Potential Measurement I. Katsumata, Y. Sakai and T. Oshio — 190

E3 Supersound Plasma Counter-Streaming Interaction and Thermalization inside the Open Magnetic Traps V. M. Alipchenkov, R. G. Bikmatov, N. V. Goryacheva, A. M. Zhitluhin, I. V. Ilyushin, A. D. Kiskin, I. K. Konkashbaev, V. N. Lyashenko, L. B. Nikandrov, S. A. Ravichev, Yu. V. Skvortsov, V. G. Solovyeva, V. M. Strannikov, F. R. Ulinich, F. R. Hummeedoollin and S. S. Tserevitinov — 197

E4 Collision of High Energy Plasma Streams T. Uyama, S. Ohi, N. Satomi, K. Watanabe, S. Gotô and H. Itô — 201

Program — 212 Itinerary — 217 Participants List — 218

A1 Status of JT-60 Diagnostics

A1 STATUS OF JT-60 DIAGNOSTICS

Yasuo Suzuki Japan Atomic Energy Research Institute

The content of my talk is classified as follows:

  1. General Description of JT-60 Device,
  2. Status and Schedule of JT-60 Project including Schedule of Experiment,
  3. Status of JT-60 Diagnostics,
  • Diagnostics to be prepared for the First Phase of Experiment and Advanced Diagnostics for the Second Phase of Experiment,
  • Problems and Research and Development,

  1. System Consideration of JT-60 Diagnostics.

  2. JT-60 DEVICE JT-60 is a large tokamak device with objectives of producing reactor-grade plasmas and investigating their physical and technological aspects relevant to fusion reactor development.

Figure 1 shows the bird’s-eye-view of JT-60 machine and major parameters of JT-60 are listed in Table 1. In the past years there have been changes in the design and decisions in selecting one out of many alternatives. These changes, however, reflect the results of design examination and are the improvement or simplifications in-nature. There was no change in the major parameters of JT-60.

JT-60 is primarily designed for non-DT experiments. Although this choice precludes DT-burn physics studies in JT-60, it provides flexibility in the machine design and permits detailed studies of plasma physics and fusion technologies in reactor-grade plasmas. For that objective the design temperatures and confinement time are up to 10 keV and 1 sec., respectively, within a factor of two of reactor values. A long discharge duration of 5 - 10 sec is incorporated in the design.

Diagnostics are made along vertical and horizontal view lines and also along lines at about 40 degrees with the median plane. Most of the diagnostics are placed on a diagnostic table placed above the machine and the diagnostic table are held independently by the building. Other diagnostic instruments are placed under the lower support and at the place between the adjacent neutral beam injectors.

  1. STATUS AND SCHEDULE OF JT-60 PROJECT In April 1978, the fabrication of JT-60 machine was started. The tokamak machine is being fabricated by Hitachi Ltd. The power supply for the poloidal field coils is also being constructed by Toshiba Corporation. The construction of the computerized control system and the power supply of the Toroidal Field Coil will begin in a few months.

Design work of the experimental building is now completed and the construction will begin in the near future. Heating and diagnostic devices require further development. Fabrication of the prototype neutral beam injector for heating and hardware development of diagnostic instruments have started this year.

JT-60 will be located at a new site near Tokai Establishment of JAERI which will accommodate not only JT-60 but also two more generations of devices after JT-60 and other engineering facilities. The site procurement has been completed on the first of October.

The total completion of JT-60 is expected in December 1983.

After the completion of JT-60, that is, from 1984, the experiment will begin. The experimental plan and schedule are established. The experimental schedule is divided into three steps.

The first step of experiment is devoted to produce the target plasma with joule heating in order to enable injection of neutral beam (Phase I) and to provide the production of break even plasma by neutral beam injection heating and RF power heating (Phase II). The second step of experiment will aim at the long pulse discharge control and modeling test of reactor-grade plasma. After the reconstruction, the Proto-ETR test experiment is planned as the third step.

Arrangement and instrumentation of diagnostic devices will be changed in accordance with the purpose of Experiment. Instruments to be installed in the vacuum chamber, such as electro-magnetic probes, Rogowski coils and so on will be completed before the performance test. Most of diagnostics will be prepared at the start of the first experimental step. Adding the advanced diagnostics (B group) and improving the diagnostic performance, the various diagnostics will be applied to the JT-60 device.

  1. STATUS OF JT-60 DIAGNOSTICS Scoping studies of JT-60 diagnostics were started in 1976 and the first equipment plan of the diagnostics was made successively. The program of both the whole diagnostic system and each diagnostic instrument went through stages of conceptual design picking up the technical problems on the application of the diagnostics for the large tokamak and the stage of technical developments in order to solve the problems in the instrumentation of the diagnostics.

In this year, we have reexamined the first plan of diagnostics and selected optimal diagnostic instruments, in the light of the fabrication status of JT-60 device and the experimental schedule and purposes.

In the large tokamak experiments, the diagnostics should work not only for the understanding of plasma behavior but also for the control of plasmas in a broad sense, that is, for the production of plasmas of high quality. The diagnostics should be also the sensors of safety protection because the thermal and electrical interactions will be large between plasma and tokamak machine.

On the other hand, the high accessibility of the diagnostics to the plasma is not obtained in the large tokamaks and the duty cycle of the discharge is very low; one discharge per 10 minutes in JT-60 case. So, each diagnostics should obtain the useful data with highly temporal and spatial resolution simultaneously and the data processing system should work efficiently.

Diagnostic instruments for the JT-60 can be classified as follows; for phase I experiments (Group A): (1) Electromagnetic sensors, (2) interferometers, (3) Thomson scattering system, (4) spectrometers, (5) X-ray analysers, (6) neutral particle analysers, (7) boundary layer analysis equipments, (including monitors and analysers of first wall conditions), (8) neutron counters, and as advanced diagnostics, (mainly for phase II experiment, Group B): (9) FIR laser scattering, (10) resonance scattering, (11) fluctuation analysis, (12) neutron measurements, (13) ion density distribution measurements in respect to H, D, T and He.

Most of the diagnostics ports have been assigned to the diagnostic instruments and the space and the setting method are presently under consideration.

The items of research and development for each diagnostics mentioned above, which has been carried out recently by JAERI with the laboratories and industries, will be reported at the Seminar. An example of design work is shown in Fig. 2 which is illustration of Thomson scattering system.

  1. SYSTEM CONSIDERATION OF JT-60 DIAGNOSTICS We have many items of experiments during short time but discharge frequency is very low. So, the efficient use of every discharge shot is essential. In other words, the control devices and data processing are essential.

Let us consider the functions of diagnostics and data processing device in the execution of experiment. We can draw a flow chart of the decision process of the experimental conditions of experiment as shown in Fig. 3. There will be four loops to let the diagnostic data reflect on the experimental procedures, such as real time feedback loop, shot by shot loop, day-unit loop and week-unit loop, in which different analysis processes may exist. Diagnostics and data processing system should be useful for each analysis process.

We are going to realize this experimental scheme with the hierarchical computerized system of control and data processing so that these control loops may work actively, systematically, and efficiently.

The computer system of JT-60 control and data processing is shown in Fig. 4. The data processing system (the right hand side of Fig. 4) is composed of computers of three ranks: the first is center computers which is composed of high level large computers which service as a processor system of week-unit loop, the second is inter-shot data processors which are located in the computer room of JT-60 control building and act as processor system of day-unit and shot by shot loops. This computer system is composed of minicomputers. The third is real time data processor which can be connected to the device control system. The computers in this rank are composed of micro-computers incorporated in the CAMAC modules.

Table 1 MAJOR PARAMETERS OF JT-60

  • Major radius (R): 3.0 m
  • Minor radius (a): 0.95 m
  • Toroidal field (BT): 45 kG
  • Flat top: 10 sec
  • Plasma current (Ip): 2.7 MA
  • NBI power (Pinj): 20 MW
  • RF power (PRF): 10 MW

A2 Diagnostic Complex of T-15

A2 DIAGNOSTIC COMPLEX OF T - 15

D. V. Orlinskii, presented by A. Stefanovsky Kurchatov Institute of Atomic Energy

Scientific program of T-15 device is the natural continuation of the works which were carried out on smaller devices till now: investigation of feasibility and characteristics of additional heatings (SHF on TM-3, neutral injection on T-11); investigation of influence of impurities and of transport phenomena on the balance of energy in plasma. The power of additional heating is supposed to be sufficient for achievement of thermonuclear temperature (~ 15keV) that is one of the most important task of T-15. Investigations of energy balance in plasma, of energy loss channels and their nature, of impurity problem - their behavior in plasma, composition, origin and so on are closely connected with the main aim.

The main parameters of the device and assumed plasma parameters are given in Table I. The schematic sight of the device construction is shown in Fig. 1 and 2. The vacuum chamber consists of 24 cylindrical stainless steel pieces, 12 of which are connecting bellows and other 12 are solid cylinders with three holes for ports. The inner side of chamber can be armoured by any other materials plates. Circular toroidal superconducting coils are placed in the vacuum chamber of cryostat and enclosed from the discharge chamber with heat screens. The vertical field coils are disposed on outer side of toroidal coils. All these systems and iron magnet with 12 outer cores are situated in vacuum chamber of cryostat.

The following peculiarities of the device are of importance for plasma diagnostics:

  1. The magnetic field in the diagnostic disposition place is less than 250 oersted.
  2. The distances between plasma axis and port flanges are very large: 2 meters in vertical port (given in Fig. 3) and 3 meters in horizontal one (see Fig. 4).
  3. The inner wall of chamber is accessible without dismantling of device and can be useful for set of diagnostics.

It should be underlined that the diagnostic itself has a number of peculiarities connected with large size of plasma, its high plasma parameters, the volume of the experiment and its cost.

  1. Many measurements must be doubled to ensure high reliability.
  2. The sizes of plasma column and space resolution of different diagnostics (especially active) let us carry out local measurements for many plasma parameters that is very important for the experiment.
  3. Transition to shorter wavelengths is necessary in measurements of plasma density and electron temperature. It leads to treatment of new instruments.
  4. Automatization of acquisition and analysis of experimental data.

Some groups of methods, shown in Fig. 5, can be outlined in diagnostic complex of T-15:

  1. Electromagnetic measurements, including measurements of current, voltage, toroidal and poloidal fields and diamagnetic signal. Under some conditions, from these values one can calculate plasma energy storage, heating power, plasma pressure, mean conductivity (and therefor Zeff) and q(a). All these quantities are integral, required in all experiments.
  2. Parameters of electrons are defined by submillimeter interferometry, laser scattering and measurements of bremsstrahlung and cyclotron radiations.
  3. Temperature and density of hydrogen or deuterium ions will be measured with the help of active and passive corpuscular methods, neutron emission and doppler spread of impurities lines.
  4. Energy and particle balance and impurities behavior will be studied with bolometers, by measurement of plasma radiation intensity in the wide spectral range and by charge-exchange between fast neutral atoms and impurity ions.
  5. The plasma stability is supposed to be investigated with magnetic probes, resonance Rogovsky coils, soft and hard x-rays detectors and later on by microwave scattering.
  6. The usefulness of other diagnostic methods for T-15 particularly connected with investigation of plasma-wall interaction (resonance fluorescence, Auger-spectroscopy of samples and so on) is studied now.

The diagnostics, marked with solid lines in Fig. 5, form the main minimal set of methods, giving sufficient information about plasma parameters:

  1. Electromagnetic methods in main variant.
  2. 2-3 pyroelectric detectors;
  3. 3-channels interferometer;
  4. Thomson scattering in three points;
  5. x-ray spectroscopy radiation along main diameter;
  6. cyclotron radiation from central plasma region measurement;
  7. energetic spectrum of charge-exchange neutrals;
  8. integral neutron radiation;
  9. intensity of impurity lines in soft x-ray range.

Other methods, as a rule, give additional information and can be regarded as a second group.

TABLE 1. PARAMETERS OF T-15

  • Toroidal magnetic field on the axis: 3.5 T
  • Major radius: 2.4 m
  • Minor plasma radius: 0.7 m
  • Plasma current: 1.4 MA
  • Duration of flat part of current pulse: up to 5 s
  • Number of pulses per hour: 6
  • Working gas: H2
  • Plasma density: 5-7 x 10^13 cm^-3
  • Energy confinement time: 0.3 s

A3 Diagnostics in Heliotron-E

A3 DIAGNOSTICS IN HELIOTRON-E

Heliotron E Group Plasma Physics Laboratory, Kyoto University, Gokasho, Uji, Japan

Introduction: The object of the researches in Heliotron-E is to confine and heat plasma in the heliotron magnetic configuration. The project of the Heliotron-E started from 1976 and the device will be completed in spring of 1980.

Diagnostics Planning Requirements: (1) Prepare more than one diagnostic technique for each physical quantity. (2) Both time evolutions and radial profiles should be obtained on a single discharge basis.

Key Diagnostic Systems:

  • Electron Density: Measured by 2 mm microwave interferometer with five channels, and FIR-laser interferometer under design.
  • Electron Temperature: Measured by ruby laser Thomson scattering (delivering two pulses per discharge, 100 ms interval, 10 J output), soft X-ray PHA system (10^5 counts/sec), and cyclotron harmonic emission (heterodyne receiver scanning 75-110 GHz every 10 ms).
  • Ion Temperature: Estimated by 10-channel mass resolved energy analyser (0.2-50 keV) for charge exchange fast neutrals, and Doppler broadening of impurity ion lines with SPEX 1.26 m Czerny-Turner monochromator.
  • Impurities: Measured by McPherson 2.2 m grazing incidence monochromator (10-1250 Å).
  • Data Acquisition System: Hierarchical system utilizing OKI Co. standards, CAMAC interfaces, and an OKITAC 50/40 minicomputer with 30 Mbyte disk storage.

Table 1 & 2 Parameters of Heliotron E:

  • Major Radius: 2.2 m
  • Minor Radius: 0.21 - 0.4 m (long axis 0.3 m, short axis 0.15 m)
  • Toroidal Field Component: 2 Tesla
  • Helical Field Current: 1.16 MA
  • Plasma Volume: 1.7 m^3
  • Electron/Ion Temperature: ~1 keV / ~800 eV
  • Plasma Density: 1 x 10^20 m^-3 (10^14 cm^-3)
  • Energy Confinement Time: > 10 msec
  • Plasma Current: 120 kA

A4 Works on Plasma Diagnostics in KhPTI

A4 WORKS ON PLASMA DIAGNOSTICS IN KhPTI

O. S. Pavlichenko, V. I. Tereshin Kharkov Physical Technical Institute

Main subjects of plasma diagnostic studies in KhPTI are laser resonance fluorescence, IR and submillimeter laser interferometry and particle diagnostics.

  1. Laser Resonance Fluorescence: Resonant scattering of L_alpha and H_alpha radiation for hydrogen and impurity atom spatial profiling (O, C, Fe, Mo, W). Saturation parameters, pumping schemes, and dye lasers (Rhodamine 6G, Cresyl Violet) are discussed.

  2. Submillimeter and Infrared Laser Interferometry:

  • HCN-laser (lambda = 337 um) interferometer with scanning rate of 0.4 cm/usec for spatial density distributions.
  • CO2-laser (lambda = 10.6 um) Michelson interferometer with reference pathlength modulation for dense plasma sources (theta-pinches, plasma guns).
  1. Particle Diagnostics:
  • 5-channel electrostatic reflex analyzer (0.05 - 20 keV) for ion temperature measurements.
  • Local ion temperature measurement using hydrogen atom targets generated by coaxial plasma guns.
  • Small angle neutral particle elastic scattering for ion temperature profile measurements.

A5 Plasma Diagnostics on JIPP T-II Stellarator/Tokamak

A5 PLASMA DIAGNOSTICS ON JIPP T-II STELLARATOR/TOKAMAK

Junji Fujita Institute of Plasma Physics, Nagoya University, Nagoya 464

Introduction & Device Parameters: JIPP T-II is a hybrid stellarator/tokamak device (R = 91 cm, a = 17 cm, Bt = 3 T max, l = 2, m = 4 helical windings). Operating regimes include Ohmic heating, NBI heating (25 kV, 150 kW x 2), Lower Hybrid heating (0.8 GHz, 160 kW), and ECH (35.5 GHz, 130 kW).

Diagnostics:

  • High-speed TV camera system with fast vertical scanning for plasma shape and position monitoring.
  • 2 mm microwave and HCN laser (337 um) interferometers with direct readout.
  • High collection efficiency ruby laser Thomson scattering system.
  • Fast scanning Fourier spectrometer for synchrotron radiation measurement.
  • Neutral beam probing using neutral lithium beams for scrape-off layer investigations.

A6 Plasma Diagnostics on Emission and Scattering of Electromagnetic Waves

A6 PLASMA DIAGNOSTICS IN TOKAMAKS ON EMISSION AND SCATTERING OF ELECTROMAGNETIC WAVES

V. V. Rozhdestvensky A. F. Ioffe Physico-Technical Institute of the USSR Academy of Sciences

  1. Cyclotron Emission Diagnostics: Physical bases of local electron temperature measurement via cyclotron emission (fundamental and harmonics) in inhomogeneous magnetic fields. Considerations of optical thickness, black-body emission, reception conditions, spatial resolution, wall reflections, and non-thermal superthermal radiation associated with runaway electrons and auxiliary heating.

  2. Enhanced Scattering in the Presence of a Singular Point: Theoretical and experimental study of collective fluctuation scattering enhanced near hybrid resonance transformation points (Trivelpiece-Gould modes) in a linear plasma installation.

A7 Density Fluctuations Using Homodyne Wave Scattering

A7 MEASUREMENTS OF NONSTATIONARY AND ANISOTROPIC DENSITY FLUCTUATIONS USING ELECTROMAGNETIC WAVE SCATTERING

Takashige Tsukishima, Osamu Asada, Kazuo Yoshioka and Akira Inoue Faculty of Engineering, Nagoya University, Nagoya 464

A new homodyne detection system capable of distinguishing upper (blue) and lower (red) sidebands of scattered radiation from plasma density fluctuations is described. The method utilizes a single microwave source (70 GHz), split into dual local channels with a pi/2 phase shifter and magic tees. Experimental demonstration of anisotropic fluctuations in a linear turbulently heated plasma (THE NU-I) is presented.

A8 Far-Infrared Laser for Tokamak Diagnostics

A8 A TWIN OPTICALLY-PUMPED FAR-INFRARED CH3OH LASER FOR THE LARGE TOKAMAK PLASMA DIAGNOSTICS

M. Yamanaka, Y. Takeda, S. Tanigawa, A. Nishizawa, N. Noda, J. Fujita, M. Takai, M. Shimobayashi, Y. Hayashi, T. Koizumi, K. Nagasaka, S. Okajima, Y. Tsunawaki, and A. Nagashima

A twin optically-pumped far-infrared CH3OH laser system operating at 118.8 um and 70.5 um is constructed for modulated interferometry in large tokamaks. Anti-symmetric doublets resulting from Raman-type resonant two-photon transitions provide a frequency shift of several MHz for phase modulation. Stable beat signals at 1 MHz were verified using a Ge-Ga detector.

A9 SMM Wave Laser Scattering Apparatus

A9 DEVELOPMENT OF SMM WAVE LASER SCATTERING APPARATUS FOR THE MEASUREMENTS OF WAVES AND TURBULENCES IN THE TOKAMAK PLASMA

T. Saito, Y. Hamada, T. Yamashita, M. Ikeda, M. Nakamura and S. Tanaka Department of Physics, Kyoto University

Development of a submillimeter (SMM) wave scattering system using a transversely excited (TE) pulsed HCN laser (discharge length 1.4 m) and a Schottky barrier diode mixer with corner reflector for heterodyne detection of RF-driven waves and turbulence during lower hybrid heating.

B2 Elongation Ratio in Non-circular Tokamaks

B2 METHODS OF DETERMINING THE ELONGATION RATIO IN A NON-CIRCULAR TOKAMAK

S. Shinohara and Miyamoto-Toyama Group Department of Physics, Faculty of Science, University of Tokyo

Four methods for determining plasma elongation in the TNT-A non-circular tokamak (R0 = 40 cm, Bt <= 4.4 kG): (1) Thomson scattering electron temperature and density profiles, (2) external magnetic probe and one-turn loop flux reconstruction, (3) direct internal magnetic probe current profiling, and (4) Mirnov oscillation mode analysis. Maximum elongation kappa = 1.5 was achieved at decay index n_x ~ -0.7.

B3 Circular and Elliptic Plasma in TORIUT-4

B3 EXPERIMENTAL INVESTIGATION OF CIRCULAR AND ELLIPTIC PLASMA COLUMN IN TORIUT-4

M. Kikuchi, N. Inoue, M. Mori, K. Moriya, K. Miyata, K. Okano and T. Uchida Department of Nuclear Engineering, University of Tokyo

Investigation of circular and non-circular discharges in TORIUT-4 (aspect ratio down to 2.6). Studies of strong and weak passive feedback control for vertical stability, pulsed shaping field effects on confinement, Mirnov oscillations, sawtooth activity, and disruptive instabilities.

B4 Feedback Control of Plasma Position in JIPP T-II

B4 FEEDBACK CONTROL OF PLASMA POSITION IN JIPP T-II

Satoshi Itoh, Kazuo Toi and Kiyokata Matsuura Institute of Plasma Physics, Nagoya University

Analysis and design of a digital computer-based vertical magnetic field control system using thyristors and magnetic probe inputs based on the Mukhovatov-Shafranov relationship. Bode diagram stability analysis and compensation techniques are detailed.

B5-a Feedforward-Feedback Position Control in JIPP T-II

B5-a CONTROL OF HORIZONTAL PLASMA POSITION BY FEEDFORWARD-FEEDBACK SYSTEM WITH DIGITAL COMPUTER IN JIPP T-II TOKAMAK

K. Toi, K. Sakurai, S. Itoh, K. Matsuura, S. Tanahashi Institute of Plasma Physics, Nagoya University

Successful real-time digital position control (sampling interval 1.39 ms) incorporating PID feedback and feedforward current compensation in JIPP T-II, suppressing horizontal plasma displacement within 1 cm during high-density, low-q discharges.

B5-b Confinement in High-Field Tokamak TRIAM-1

B5-b CONFINEMENT OF OHMIC- AND TURBULENT-HEATED PLASMAS IN SMALL HIGH-FIELD TOKAMAK TRIAM-1

K. Toi, S. Itoh, Y. Kawai, N. Hiraki, K. Nakamura, O. Mitarai Kyushu University

High-density (n_e = 1-2 x 10^14 cm^-3) ohmic and turbulent heating experiments in TRIAM-1 (R = 25.4 cm, Bt = 40 kG). Turbulent heating pulses (E >> E_Dreicer) increased bulk ion temperature from 140 eV to 260 eV with neoclassical thermal decay times.

C1 Poloidal Divertor Experiment in DIVA/JFT-2a

C1 POLOIDAL DIVERTOR EXPERIMENT IN DIVA/JFT-2a

DIVA Group, presented by Yasuo Shimomura JAERI

Summary of experimental findings on DIVA axisymmetric divertor tokamak (1974-1979). Topics include metallic impurity production mechanisms (sheath-accelerated self-sputtering), boundary scrape-off layer scaling laws, impurity shielding/backflow, and confinement improvements.

C4 Impurity Spectra in Tokamak Plasmas

C4 ROLE OF IMPURITY SPECTRA IN TOKAMAK PLASMAS

K. Mori Institute of Physical and Chemical Research (IPCR)

Review of spectroscopic diagnostics of high-Z impurities (iron, molybdenum, tungsten, gold) in tokamaks, atomic transition probabilities, coronal equilibrium vs. transport simulations, satellite line diagnostic techniques, and Doppler broadening measurements.

D1 Optical Diagnostics for Plasma Focus

D1 SOME OPTICAL DIAGNOSTICS FOR THE PLASMA FOCUS

V. M. Korzhavin

Experimental studies on plasma focus dynamics (50 kJ, 1.2 MA) using fast multi-frame electro-optical photography (20 ns shutter), Mach-Zehnder ruby laser interferometry, and infrared (2-15 um) emission diagnostics utilizing fast Ge:Zn detectors (10^-9 s resolution) to detect superthermal emission from low-frequency plasma turbulence.

D2 Dense Plasma Focus Holography

D2 DIAGNOSTICS OF DENSE PLASMA FOCUS BY RUBY LASER HOLOGRAPHY

M. Yokoyama, Y. Kitagawa, I. Tsuda, Y. Yamada and A. Ishizaki Institute of Laser Engineering, Osaka University

Two-nanosecond ruby laser holographic interferometry of dense plasma focus evolution. Identified five subphases: compression, very dense (n_e ~ 2 x 10^19 cm^-3), expanded, unstable (m = 0 sausage / m = 1 kink), and decay phases.

D3 Computer Processing of Interferograms

D3 INTERFEROGRAM PROCESSING BY HELP OF A COMPUTER

D. B. Lazebnik, A. P. Petrov, S. S. Tserevitinov I. V. Kurchatov Institute of Atomic Energy

Automated microdensitometer systems (YBB, AMD) and software library (‘SPFI’) for digitized reconstruction, fringe filtering, phase-function calculations, and Abel inversion of optical plasma interferograms with 1-2% accuracy.

E1 Diagnostics for GAMMA-6 Tandem Mirror

E1 PLASMA DIAGNOSTICS FOR GAMMA-6 EXPERIMENT

K. Ishii, T. Kawabe, S. Miyoshi University of Tsukuba

Development of a negative gold ion beam probe (Au-) utilizing double detachment (Au+ energy gain 2e*phi) and photodetachment to measure internal space potentials and ambipolar potential differences in the GAMMA-6 tandem mirror.

E2 Heavy Ion Beam Probe for Potential Measurement

E2 HEAVY ION BEAM PROBE FOR POTENTIAL MEASUREMENT

Itsuo Katsumata, Yoshiyuki Sakai, and Takanori Oshio Osaka City University

Development of a compact, in-vessel heavy ion beam probe (Cs+, Ba+) utilizing secondary doubly charged ions detected by a multi-grid energy analyzer with an electrostatic ion filter to eliminate UV background noise in magnetized plasmas up to 2 kG.

E3 Counter-Streaming Plasma Interaction in Magnetic Traps

E3 SUPERSOUND PLASMA COUNTER-STREAMING INTERACTION AND THERMALIZATION INSIDE THE OPEN MAGNETIC TRAPS

V. M. Alipchenkov et al. I. V. Kurchatov Institute of Atomic Energy

Theoretical and experimental study of supersonic collision and thermalization of high-density plasma streams (T_i ~ 1-10 keV, n ~ 10^16 - 10^18 cm^-3) in open magnetic traps, examining shock wave formation, three-fluid deceleration models, and hose instability-driven turbulent thermalization.

E4 Collision of High Energy Plasma Streams

E4 COLLISION OF HIGH ENERGY PLASMA STREAMS

Tadao Uyama, Shoichi Ohi, Norio Satomi, Kenji Watanabe, Seiichi Gotô, and Hiroshi Itô Osaka University

Experimental investigations of high-energy plasma stream collisions in linear (PIACE-L1), sector (PIACE-S1, 90-degree), and toroidal (PIACE-T1) devices. Demonstrated efficient translational-to-thermal energy conversion (T_i up to 600 eV) and rapid subsequent theta-compression heating.

Seminar Program & Itinerary

PROGRAM & ITINERARY

Dates: November 13 - 17, 1979 Location: Institute of Plasma Physics, Nagoya University (Conference Room, 8th Fl.)

Sessions:

  • Session A: Diagnostics on Large Thermonuclear Fusion Devices (Chairmen: T. Okuda, O. Pavlichenko, K. Matsuura, S. Grebenshchikov)
  • Session B: Diagnostics on Position and Radial Profile of Plasma Column (Chairmen: Y. Suzuki, V. Rozhdestvensky)
  • Session C: Diagnostics on the Effect of Divertor on Plasma Parameters (Chairmen: K. Miyamoto, S. Tserevitinov)
  • Session D: Diagnostics on High Beta Plasma in Pulsed Nuclear Fusion Systems (Chairmen: T. Tsukishima, A. Stefanovsky)
  • Session E: Diagnostics on Open System and New Trends (Chairmen: K. Watanabe, V. Korzhavin)

Itinerary:

  • Nov. 12: Arrival at Narita / Nagoya
  • Nov. 13-16: Seminar sessions at IPP Nagoya University
  • Nov. 17: Tour of IPP Nagoya University
  • Nov. 18-19: Kyoto & Uji (Heliotron Research Center, Kyoto University)
  • Nov. 20: Osaka (Plasma Physics Lab & ILE, Osaka University) -> Tokyo
  • Nov. 21: JAERI Tokai Establishment Tour
  • Nov. 22: University of Tokyo Tour
  • Nov. 23: Departure from Narita

Participants List

PARTICIPANTS LIST

USSR Participants:

  • O. Pavlichenko (Kharkov Physico-Technical Institute)
  • V. Korzhavin (USSR State Committee of Atomic Energy, Moscow)
  • S. Grebenshchikov (Lebedev Institute of Physics, Moscow)
  • V. Rozhdestvensky (Ioffe Physico-Technical Institute, Leningrad)
  • A. Stefanovsky (Kurchatov Institute of Atomic Energy, Moscow)
  • S. Tserevitinov (Kurchatov Institute of Atomic Energy, Moscow)

Japan Participants:

Download
Get the complete research paper as a publication-ready PDF.
US Paper PDF (v4) China PDF Israel PDF Russia PDF Japan PDF
Version History
v4 (Current) v2 (Archived) v1 (Original)