The University of Missouri-Columbia (UMC) recently obtained a magnet test dewar, which was initially used in the early 1970s at the NASA Lewis Research ...
From:
ADVANCES IN CRYOGENIC ENGINEERING, Vol. 29 Edited by R. W. Fast (Plenum Publishing Corporation, 1984)
DESIGN, CONSTRUCTION, AND TESTING OF A LARGE BORE SUPERCONDUCTING MAGNET TEST FACILITY (SMTF) AT THE UNIVERSITY OF MISSOURI-COLUMBIA M. Peck, s. McGhee, W. Meyer*, W. Miller, M. Prelas, B. Reed, and C. Wallace University of Missouri-Columbia Columbia, Missouri
INTRODUCTION The University of Missouri-Columbia (UMC) recently obtained a magnet test dewar, which was initially used in the early 1970s at the NASA Lewis Research Center for testing large bore superconducting coilsl, In the late 1970s, a 0,4 metre diameter warm tube was added to the original dewar. This configuration was used sparingly and was subsequently surplused to UMC. The dewar was initially obtained by UMC to test three large bore superconducting magnets which were originally used in the NASA Lewis Superconducting Magnetic Mirror Apparatus project 2 •3 (SUMMA). A test area was assembled at the Dalton Research Center on the UMC campus 4 , where two of the SUMMA magnets have been successfully tested. These tests served two purposes in that, 1) coil operation was verified (a key goal of the UMC program 5), and 2) the integrity of the dewar with the warm tube modification was demonstrated, The latter aspect has significance to studies which require the expoure of warm samples to high magnetic fields with axial symmetry. Examples of such applications include studies of the synergistic effects of magnetic fields with radiation on life forms, and 6the flow of coolants in channels exposed to .high magnetic fields • *Present address: Institute for Energy Research; Syracuse University; Syracuse, New York 13210 49
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M. Peck et al.
TEST ASSEMBLY · · · The heart of the SMTF is the test dewar. Since the dewar is approximately 4.29 metres high it was decided that a pit was required. With this configuration, the coil support system (which bolts to the dewar lid and is approximately 4.26 metres high) can be safely inserted into the dewar. The dewar and support system were designed to accommodate solenoidal magents with outside diameters of 0.9 metres, winding heights of one metre, and bores greater than 0.5 metres. The SMTF also accommodates additional support equipment, which includes six 0 to 500 amp D.C. power supplies and ramping computers for powering the magnets, and a CAMAC-based LSI 11/23 computer for data acquisition, storage, and analysis. The latter unit was used in the tests of the SUMMA coils to collect and process data from 27 instruments. With this equipment, a variety of field configurations and instrumentation is possible for the examination of warm samples in high magnetic fields. The warm tube can be accessed from both ends, which suggests that a variety of field profiles can be generated with the two coils.
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SMTF two magnet assembly, as shown beside the magnet holding assembly.
Design, Construction, and Testing of a Large Bore SMTF
51
Field configurations can be generated with one or two coils. (Tests of the magnets during the SU~1A project were made with one coill.) A new support system has been designed to accommo~ date two coils with a 0.92 metre separation, in addition to positioning the magnets on top of one another (see Figure 1). Additionally, each magnet has three separate modules which can be powered individually to different currents. The possibility of operating the magnets in the three configurations described above, plus the modular operation of the magents, presents a wide variety of field configurations in the warm tube. As can be seen in Figure 2, ules is operated, the modularity of the radial field gradients in tainable with a single magnet is
when a single magnet with two modof the magnet provides some control the warm tube. The peak field ob5 tesla.
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Single coil magnetic field profile.
52
M. Peck et al.
When two magnets are placed on top of one another, the peak field increases to 7.2 tesla on axis (see Figure 3). Note also that with two coils the radial gradients do not change perceptibly from the case of the single magnet. This implies that many of the field configurations which are possible with one magnet can be approximately duplicated with two coils at higher field intensitities (see Figure 4). The third configuration provides unique fields between the coils which could be of interest to studies in plasma physics (see Figure 5). CONCLUSIONS Verification of the proper functioning of a magnet test dewar with a large warm tube has been demonstrated. In addition, the operation of
CIIFIUIATIIN 8 2 AI~ACEMT COILS
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Figure 3.
Two stacked coils field profile.
Design, Construction, and Testing of a Large Bore SMTF
53
two large bore superconducting magnets was verified with the test dewar. This combination provides a variety of ~agnetic field configurations in the warm tube for various studies in the life sciences, fusion technology, and materials engineering. ACKNOWLGEMENTS The authors wish to express their gratitude to Shahram Gharagozloo for his efforts in generating the magnetic field profiles, and to Glem Mcintosh, cryogenics consultant to the UMC project, and to Willard Coles, magnetics consultant to the UMC project.
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Field profile along throat for three configurations.
M. Peck et al.
54
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Magnetic mirror field profile.
REFERENCES 1. 2. 3. 4.
J. Reinmann, M. Swanson, C. Nichols, S. Obloy, L. Nagy, and F. Brady, "NASA Superconducting Magnet Facility", NASA Technical Memorandum, NASA TMX-71480 (Nov. 1973). J. Laurence, W. Coles, G. Brown, and E. Meyn, ''Performance Test -. of 51 em Bore Superconductive Magnets for a Magnetic Mirror Apparatus", NASA Technical Memorandum TMX-711480 (Nov. 1973). W. Coles, G. Brown, E. Meyn,.and E. Scrader, "Pumped Helium Test of a 51 em Bore Niobium-Titanium Magnet", NASA TnD-1558 (1969). M. Peck, B. Reed, M. Prelas, and W. Meyer, Performance test of two 21.5 inch bore superconducting magnets for use in the Missouri mirror fusion project, 1983 IEEE International Conference on Nuclear plasma Science, Library of Congress # 81-644315 San Diego, CA, pp 157 (May 1983) •
Design, Cotistruction, and Testing of a Large Bore SMTF
5.
6.
55
M. Peck, S. Adams, S. Glenn, S. McGhee, B. Reed. C. Wallace, and M. Prelas, Design of a large bore superconducting mirror device, 1983 IEEE International Conference on Nuclear and Plasma Science, Library of Congress # 81-644315, San Diego, CA pp. 84 (May 1983). R. Jnhala, W. Meyer, W. Miller, and M. Prelas, "Conceptual Design Report: University of Missouri-Columbia Mirror Plasma Research and Fusion Engineering Facility", University of Missouri, Columbia, MO (Apr. 22, 1983).
