17 Matching Results

Search Results

Advanced search parameters have been applied.

in creator/contributor: "Campbell, G. L."

open access

The multipulse Thomson scattering diagnostic on the DIII-D tokamak

This paper describes the design and operation of a 40-spatial channel Thomson scattering system that uses multiple 20 Hz Nd:YAG lasers to measure the electron temperature and density profiles periodically throughout an entire plasma discharge. Interference filter polychromators disperse the scattered light which is detected by silicon avalanche photodiodes. The measurable temperature range from 10 eV to 20 keV and the minimum detectable density is about 2 {times} 10{sup 18} m{sup {minus}3}. Las… more

Date: September 1, 1991

Creator: Carlstrom, T. N.; Campbell, G. L.; DeBoo, J. C.; Evanko, R. G.; Evans, J.; Greenfield, C. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design and operation of the multipulse Thomson scattering diagnostic on DIII-D

This paper describes the design and operation of a 40 spatial channel Thomson scattering system that uses multiple 20 Hz Nd:YAG lasers to measure the electron temperature and density profiles periodically throughout an entire plasma discharge. As many as eight lasers may be fired alternately for an average measurement frequency of 160 Hz, or they may be fired in rapid succession (< 10 kHz), producing a burst of pulses for measuring transient events. The high spatial resolution (1.3 cm) and wide… more

Date: March 1, 1992

Creator: Carlstrom, T. N.; Campbell, G. L.; DeBoo, J. C.; Evanko, R.; Greenfield, C. M.; Haskovec, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design of the advanced divertor pump cryogenic system for DIII-D

The design of the cryogenic system for the D3-D advanced divertor cryocondensation pump is presented. The advanced divertor incorporates a baffle chamber and bias ring located near the bottom of the D3-D vacuum vessel. A 50,000 l/s cryocondensation pump will be installed underneath the baffle for plasma particle exhaust. The pump consists of a liquid helium cooled tube operating at 4.3{degrees}K and a liquid nitrogen cooled radiation shield. Liquid helium is fed by forced flow through the cryop… more

Date: November 1, 1991

Creator: Schaubel, K. M.; Baxi, C. B.; Campbell, G. L.; Gootgeld, A. M.; Langhorn, A. R.; Laughon, G. J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A real-time digital control, data acquisition and analysis system for the DIII-D multipulse Thomson scattering diagnostic

A VME-based real-time computer systems for laser control, data acquisition and analysis for the DIII-D multipulse Thomson scattering diagnostic is described. The laser control task requires precise timing of up to 8 Nd:YAG lasers, each with an average firing rate of 20 Hz. A cpu module in real-time multiprocessing computer system will operate the lasers with evenly staggered laser pulses or in a burst mode'', where all available (fully charged) lasers can be fired at 50--100 {mu}sec intervals u… more

Date: October 1, 1990

Creator: Greenfield, C. M.; Campbell, G. L.; Carlstrom, T. N.; DeBoo, J. C.; Hsieh, C. -L.; Snider, R. T. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design and operation of the multipulse Thomson scattering diagnostic on DIII-D

Date: March 1992

Creator: Carlstrom, T. N.; Campbell, G. L.; DeBoo, J. C.; Evanko, R.; Greenfield, C. M.; Haskovec, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Installation and initial operation of the DIII-D advanced divertor cryocondensation pump

Phase two of a divertor cryocondensation pump, the Advanced Divertor Program, is now installed in the DIII-D tokamak at General Atomics and complements the phase one biasable ring electrode. The installation consists of a 10 m long cryocondensation pump located in the divertor baffle chamber to study plasma density control by pumping of the divertor. The design is a toroidally electrically continuous liquid helium-cooled panel with 1 m{sup 2} of pumping surface. The helium panel is single point… more

Date: October 1, 1993

Creator: Smith, J. P.; Schaubel, K. M.; Baxi, C. B.; Campbell, G. L.; Hyatt, A. W.; Laughon, G. J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

New DIII-D tokamak plasma control system

A state-of-the-art plasma control system has been constructed for use on the DIII-D tokamak to provide high speed real time data acquisition and feedback control of DIII-D plasma parameters. This new system has increased the precision to which discharge shape and position parameters can be maintained and has provided the means to rapidly change from one plasma configuration to another. The capability to control the plasma total energy and the ICRF antenna loading resistance has been demonstrate… more

Date: September 1, 1992

Creator: Campbell, G. L.; Ferron, J. R.; McKee, E.; Nerem, A.; Smith, T; Greenfield, C. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Recent Developments in Alternatives to Camac for Data Acquisition at Diii-D

OAK-B135 For over twenty years, data acquisition hardware at DIII-D has been based on the CAMAC platform. These rugged and reliable systems, however, are gradually becoming obsolete due to end-of-life issues, ever-decreasing industry support of older hardware, and the availability of modern alternative hardware with superior performance. Efforts are underway at DIII-D to adopt new data acquisition solutions which exploit modern technologies and surpass the limitations of the CAMAC standard. The… more

Date: October 1, 2003

Creator: Kellman, D. H.; Campbell, G. L.; Ferron, J. R.; Piglowski, D. A.; Austin, M. E. & McKee, G. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

DATA ACQUISITION AND PROTECTION FOR NEW DII-D IN-VESSEL COILS

OAK-B135 The installation of new internal magnetic coils (I-Coils) in the DIII-D tokamak at General Atomics required extensive additions to the experiment data acquisition and protection capabilities. This set of 12 coils (up to 7 kA each) is designed to allow improved feedback stabilization of resistive wall modes which limit the plasma performance. The acquisition and signal conditions needs of the I-Coil power system presented an opportunity to try a new data acquisition approach which incre… more

Date: October 2003

Creator: Campbell, G. L.; Szymanski, D. D.; Piglowski, D. A.; Kellman, D. H.; Anderson, P. M.; Jackson, G. L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Initial Results from the New Internal Magnetic Coils for Resistive Wall Mode Stabalization in the DIII-D Tokamak

OAK-B135 A set of 12 internal magnetic field coils (I-coils) has recently been installed and is being used in 2003 experiments. The purpose of this new coil set is to provide stabilization of resistive wall modes (RWM) for advanced tokamak plasmas with toroidal {beta} above the no wall stability limit. Calculations with the 3D electromagnetic code VALEN predict that the performance of this system should be superior to the previously installed external compensation coils (C-coils) by providing f… more

Date: June 1, 2003

Creator: Jackson, G. L.; Anderson, P. M.; Bialek, J.; Cary, W. P.; Campbell, G. L.; Garofalo, A. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

DIII-D Neutral Beam control system operator interface

A centralized graphical user interface has been added to the DIII-D Neutral Beam (NB) control systems for status monitoring and remote control applications. This user interface provides for automatic data acquisition, alarm detection and supervisory control of the four NB programmable logic controllers (PLC) as well as the Mode Control PLC. These PLCs are used for interlocking, control and status of the NB vacuum pumping, gas delivery, and water cooling systems as well as beam mode status and c… more

Date: October 1, 1993

Creator: Harris, J. J. & Campbell, G. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design of the advanced divertor pump cryogenic system for DIII-D

Date: November 1, 1991

Creator: Schaubel, K. M.; Baxi, C. B.; Campbell, G. L.; Gootgeld, A. M.; Langhorn, A. R.; Laughon, G. J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The development of an in-vessel cryopump system for the DIII-D tokamak

The design, testing and initial operation of the DIII-D advanced divertor cryocondensation pumping system is presented. The pump resides inside the tokamak plasma containment vessel where it provides particle exhaust pumping, and it is subjected to Joule heating and hot particle heat loads during each 10 second discharge. In addition, the pump must withstand plasma disruption induced electromagnetic forces and 400{degrees}C bake-out temperatures. Cooling is accomplished by forced flow liquid he… more

Date: July 1, 1993

Creator: Schaubel, K. M.; Baxi, C. B.; Campbell, G. L.; Laughon, G. J.; Mahdavi, M. A.; Makariou, C. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Performance characteristics of the DIII-D advanced divertor cryopump

A cryocondensation pump, cooled by forced flow of two-phase helium, has been installed for particle exhaust from the divertor region of the DIII-D tokamak. The Inconel pumping surface is of coaxial geometry, 25.4 mm in outer diameter and 11.65 m in length. Because of the tokamak environment, the pump is designed to perform under relatively high pulsed heat loads (300 Wm{sup {minus}2}). Results of measurements made on the pumping characteristics for D{sub 2}, H{sub 2}, and Ar are discussed.

Date: October 1, 1993

Creator: Menon, M. M.; Maingi, R.; Wade, M. R.; Baxi, C. B.; Campbell, G. L.; Holtrop, K. L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

DIII-D cryogenics control system status

The DIII-D cryogenics system provides liquid helium for various auxiliary systems at the DIII-D tokamak facility. The system described here executes control and supervision of the cryogenics plant and associated load systems which include four neutral beam injectors, superconducting magnets, and an in-vessel tokamak cryocondensation pump. The recent addition of this divertor cryopump represented a major increase in the scope of the control system and greater need for reliable and automatic oper… more

Date: September 1, 1993

Creator: Campbell, G. L.; Harris, J. J. & Schaubel, K. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Two phase liquid helium flow testing to simulate the operation of a cryocondensation pump in the DIII-D tokamak

A liquid helium-cooled cryocondensation pump has been installed in the DIII-D tokamak fusion energy research experiment at General Atomics. The pump is located within the tokamak vacuum chamber beneath the divertor baffle plates and is utilized for plasma density and contamination control. Two-phase helium flows through the pump at 5 to 10 g/s utilizing the heat transfer and constant temperature characteristics of boiling liquid . helium. The pump is designed for a pumping speed of 32,000 1/s. … more

Date: June 1, 1994

Creator: Laughon, G. J.; Baxi, C. B.; Campbell, G. L.; Mahdavi, M. A.; Makariou, C. C.; Smith, J. P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The DIII-D cryogenic system upgrade

The original DIII-D cryogenic system was commissioned in 1981 and was used to cool the cryopanel arrays for three hydrogen neutral beam injectors. Since then, new demands for liquid helium have arisen including: a fourth neutral beam injector, ten superconducting magnets for the electron cyclotron heating gyrotrons, and more recently, the advanced diverter cryopump which resides inside the tokamak vacuum vessel. The original cryosystem could not meet these demands. Consequently, the cryosystem … more

Date: October 1, 1993

Creator: Schaubel, K. M.; Laughon, G. J.; Campbell, G. L.; Langhorn, A. R.; Stevens, N. C. & Tupper, M. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department