Magnetic design of the axisymmetric throttle-coil addition to the tandem mirror experiment-upgrade (open access)

Magnetic design of the axisymmetric throttle-coil addition to the tandem mirror experiment-upgrade

The TMX-U magnet set has incorporated new axisymmetric throttle coils and fan-reversing transition magnets. This new magnet geometry, which will allow for the experimental verification of new physics issues related to axicell tandem mirrors, encompasses both engineering and physics considerations. Engineering considerations include structural integrity plus neutral beam and diagnostic access. Physics issues include the stability and radial transport of the confined plasma. We have calculated the magnetic field using the magnetic field code, EFFI, and the plasma stability and surface curvatures using the plasma stability code, TEBASCO. Our magnet design allows the axisymmetric throttle mirror to be varied from the end-cell mirror value of 2 to a peak of 6 T.
Date: November 28, 1983
Creator: Wong, R.L.
System: The UNT Digital Library
Normal zone detectors for a large number of inductively coupled coils (open access)

Normal zone detectors for a large number of inductively coupled coils

In order to protect a set of inductively coupled superconducting magnets, it is necessary to locate and measure normal zone voltages that are small compared with the mutual and self-induced voltages. The method described in this paper uses two sets of voltage measurements to locate and measure one or more normal zones in any number of coupled coils. One set of voltages is the outputs of bridges that balance out the self-induced voltages. The other set of voltages can be the voltages across the coils, although alternatives are possible. The two sets of equations form a single combined set of equations. Each normal zone location or combination of normal zones has a set of these combined equations associated with it. It is demonstrated that the normal zone can be located and the correct set chosen, allowing determination of the size of the normal zone. Only a few operations take place in a working detector: multiplication of a constant, addition, and simple decision-making. In many cases the detector for each coil, although weakly linked to the other detectors, can be considered to be independent.
Date: November 28, 1983
Creator: Owen, E. W. & Shimer, D. W.
System: The UNT Digital Library
Design of the electromagnetic fluctuations diagnostic for MFTF-B (open access)

Design of the electromagnetic fluctuations diagnostic for MFTF-B

The Electromagnetic Fluctuations (EMF) diagnostic will be used to monitor ion fluctuations which could be unstable in MFTF-B. Each probe assembly includes a high impedance electrostatic probe to measure potential fluctuations, and a group of nested, single turn loops to measure magnetic fluctuations in three directions. Eventually, more probes and loops will be added to each probe assembly for making more detailed measurements. The sensors must lie physically close to the plasma edge and are radially positionable. Also, probes at separate axial locations can be positioned to connect along the same magnetic field line. These probes are similar in concept to the rf probes used on TMX, but the high thermal load for 30-second shots on MFTF-B requires a water-cooled design along with temperature monitors. Each signal channel has a bandwidth of .001 to 150 MHz and is monitored by up to four different data channels which obtain amplitude and frequency information. This paper describes the EMF diagnostic and presents the detailed mechanical and electrical designs.
Date: November 28, 1983
Creator: House, P.A.; Goerz, D.A. & Martin, R.
System: The UNT Digital Library
Nova power systems: status and operating experience (open access)

Nova power systems: status and operating experience

This paper describes the pulse power systems that are used in these lasers; the status and the operating experiences. The pulsed power system for the Nova Laser is comprised of several distinct technology areas. The large capacitor banks for driving flashlamps that excite the laser glass is one area, the fast pulsers that drive pockels cell shutters is another area, and the contol system for the pulsed power is a third. This paper discusses the capacitor banks and control systems.
Date: November 28, 1983
Creator: Whitham, K.; Merritt, B. T.; Gritton, D. G.; Smart, A. J.; Holloway, R. W. & Oicles, J. A.
System: The UNT Digital Library
Improvement in MFTF data base system response times (open access)

Improvement in MFTF data base system response times

The Supervisory Control and Diagnostic System for the Mirror Fusion Test Facility (MFTF) has been designed as an event driven system. To this end we have designed a data base notification facility in which a task can request that it be loaded and started whenever an element in the data base is changed beyond some user defined range. Our initial implementation of the notify facility exhibited marginal response times whenever a data base table with a large number of outstanding notifies was written into. In this paper we discuss the sources of the slow response and describe in detail a new structure for the list of notifies which minimizes search time resulting in significantly faster response.
Date: November 28, 1983
Creator: Lang, Neil C. & Nelson, Bron C.
System: The UNT Digital Library
Electrical grounding, shielding, and isolation for the MFTF-B plasma diagnostic system (open access)

Electrical grounding, shielding, and isolation for the MFTF-B plasma diagnostic system

The electrical grounding, shielding, and isolation of plasma diagnostics on the Mirror Fusion Test Facility (MFTF-B) is a key part of the overall design. The Electromagnetic Interference (EMI) environment in which the Plasma Diagnostics System (PDS) will be required to operate is very harsh. The electrical grounding and shielding design which is being implemented to cope with this environment follows one which has been used successfully on the Tandem Mirror Experiment (TMX). Details of the MFTF-B plasma diagnostics facility, equipment grounding, shielding and isolation, and the cabling system are described in this paper.
Date: November 28, 1983
Creator: Deadrick, F. J.
System: The UNT Digital Library