MIT Reports to the President 1997-98
The primary objective of the Plasma Science and Fusion Center (PSFC) is to provide research and educational opportunities to develop a basic understanding of plasma behavior, and to exploit that knowledge by developing useful applications. The central focus of the activities at the PSFC has been to develop a scientific and engineering base for the development of fusion power. Research is being carried out, however, in a number of nonfusion areas such as ionospheric research, generation and acceleration of particle beams, laser-plasma interaction, and industrial applications of plasmas.
The Plasma Fusion Center is recognized as the leading university laboratory in developing the scientific and engineering aspects of magnetic confinement fusion and related plasma science and technology. Its research programs continue to produce significant results on several fronts: (a) experimental confinement research on the Alcator C-Mod tokamak (investigations of the stability, heating, and transport properties of compact high magnetic field, diverted plasmas), (b) the basic physics of plasmas (plasma theory, theoretical support of ITER and IGNITOR, new confinement concepts, nonneutral plasmas, coherent EM wave generation, development of high-temperature plasma diagnostics, basic laboratory and ionospheric plasma physics experiments, and novel diagnostic of inertial fusion experiments), (c) a broad program of fusion technology and engineering development that addresses problems in several areas (e.g., magnetic systems, superconducting materials, fusion environmental and safety studies, advanced millimeter-wave sources, system studies of fusion reactors, including operational and technological requirements), and (d) a significant activity in industrial application of plasmas.
Programs at the Plasma Science and Fusion Center are supported principally by the Department of Energy's Office of Fusion Energy Sciences. There are approximately 256 personnel associated with PSFC research activities. These include: 18 faculty and senior academic staff, 38 graduate students and 6 undergraduates, with participating faculty and students from Electrical Engineering and Computer Science, Materials Science and Engineering, Mechanical Engineering, Nuclear Engineering, and Physics; 77 research scientist and engineers, and 51 visiting scientists and engineers; 39 technical support personnel; and 27 administrative and support staff.
Overall funding to PSFC remained stable this year. Funding of our major research activity (the Alcator Project) rose slightly over last year and is expected to rise again next year. This year's increase, however, was offset by a reduction in a second major program at PSFC (the ITER Program). Diminished support for ITER within Congress is likely to contribute to an overall decline in PSFC funding next year. In the meantime, our staff has been aggressive in submitting new research proposals to other initiatives launched by DoE and other sponsors. As a result, we have been successful in obtaining funding at the ~ $1-million level for a new joint MIT-Columbia University magnetic confinement experiment, the Levitated Dipole Experiment (LDX).
The Alcator Division, led by Prof. Ian Hutchinson and deputy division head Dr. Earl Marmar, carries out experimental research on Alcator C-Mod, a compact, high-performance divertor tokamak devoted to investigating the physics of high temperature magnetically confined fusion grade plasmas. The total staff of the Alcator Project is about 100, including 18 full time physicists, two faculty members and 18 graduate students.
Alcator C-Mod is now well established as one of the two national centers for U.S. tokamak research, along with DIII-D at General Atomics in San Diego. Alcator C-Mod is the only high-field compact divertor tokamak experiment in operation, and therefore plays a unique role in providing critical tests of scaling and theory at high power density. Substantial collaborations with the University of Texas, Austin, and the Princeton Plasma Physics Laboratory, are making major contributions to all areas of the C-Mod research effort, with particular emphasis on plasma heating (PPPL) and diagnostic enhancements (U. Texas and PPPL). Considering these projects in combination with our smaller University and Laboratory collaborative efforts, both domestic and international, more than 20% of the total funding for C-Mod research flows to groups outside of MIT. Funding at MIT grew to $12.6M in FY98, and is expected to grow again in FY99, to about $14.4M. Nevertheless, utilization of the facility is still significantly constrained, with experimental campaigns totaling 10 weeks of operation in FY98 and an anticipated 14 weeks in FY99.
There are four key areas of investigation on Alcator C-Mod. Transport studies on C-Mod provide critical tests of empirical scalings and theoretically-based interpretations of tokamak transport at unique dimensional parameters, but with dimensionless parameters comparable to those in larger experiments. Divertor research on C-Mod takes advantage of the advanced divertor shaping, very high scrape-off layer power density, high divertor plasma density, unique abilities in diagnosis and neutral control, and a high-Z metal wall. Ion cyclotron radio frequency power provides the auxiliary heating on C-Mod, and is exploited for research into wave absorption and parasitic losses and mode conversion processes. Advanced tokamak research on C-Mod proposes demonstrating fully relaxed current profile control and sustainment through efficient off-axis current drive by radio waves in the lower hybrid range of frequencies.
In the area of transport research, we have continued investigations of enhanced confinement regimes ("H-mode") with emphasis on local measurements. Trends demonstrating a temperature threshold have been elaborated and compared to high beta edge-turbulence simulations; reasonable agreement has been obtained. New ultra high spatial resolution (~1 mm) measurements of the H-Mode edge pedestal show features with scale lengths as short as 2 mm. We have begun to gain an empirical understanding of the enhanced Da (EDA) H-mode regime, which is unique in its combination of good energy confinement, finite impurity particle confinement, and the absence of strong edge localized instabilities (ELMs), thus producing no transiently high heat loads onto the divertor. We are mapping out the plasma conditions which favor the formation of the EDA regime, and are beginning to understand the edge dynamics which produce these favorable conditions. Strong on-axis toroidal flows are observed in C-Mod during ICRF heating, and scalings of these flows with density, current and confinement properties have been measured. The flow is fastest in discharges with high stored energy, as well as those with core transport barriers (PEP mode). Such flows are very important in projecting to operation of larger, reactor-scale plasma devices, where external momentum input will be difficult or impossible to achieve.
In divertor research, we have implemented impurity injection feedback techniques to achieve quasi-steady-state detached divertor operation during EDA H-Mode plasmas. Using nitrogen, the peak divertor plate heat flux was reduced by about an order of magnitude, while the core plasma was only minimally affected by the injected impurities. This latter benefit is due, at least in part, to the effective divertor screening action which leads to a very high compression of impurity gases in the divertor volume. We have developed an analysis technique for determining the local plasma recombination rate in detached regions, using the deuterium Balmer and Lyman series radiation intensities. Opacities for the Lyman lines are measured, and the opacity effects reduce the overall recombination rates. The importance of ion-neutral friction has been verified from parallel flow measurements of ionized and neutral species in the divertor using spectroscopic techniques.
As the U.S. effort in support of the international ITER project has been decreasing, there has been renewed interest in the ignition/burning plasma mission for a next step fusion device. At the recent national fusion forum held in Madison, there was broad community support for such a step, with one embodiment being a compact, high field tokamak. As the prototype for such an experiment, C-Mod has already provided a number of important physics results needed as the basis to move along this path, and is very well positioned to continue in this role in the international program.
In the past year, the Alcator group submitted a proposal to DoE for the next five years of our research. The proposal has received very favorable peer review. Our support will change from the existing contract form to a Cooperative Agreement, with an anticipated start date of November, 1998.
Student involvement in the project remains strong. We anticipate maintaining the current graduate student number in the foreseeable future; Alcator remains the foremost university-based plasma fusion experiment.
PHYSICS RESEARCH DIVISION
Headed by Prof. Miklos Porkolab, this Division seeks to develop a theoretical and experimental understanding of plasma physics and fusion science. This Division is also a base for developing new confinement concepts, exploring inertial fusion energy and for studying space plasma physics.
FUSION THEORY AND COMPUTATIONS
Edge Plasma Physics Theory
Analytic and numerical investigations of edge plasma science for fusion relevant devices are the primary emphasis of Dr. Dieter Sigmar and coworkers. The edge plasma group aims to improve the understanding of basic plasma science phenomena and enhances the Alcator physics program by interpreting observations from the Alcator C-Mod tokamak and other fusion related devices around the world, while continuing to lead the national Divertor Task Force. The goal of this effort is to find ways to divert and control the severe heat and particle fluxes impinging on the first wall and divertor target plates of magnetic fusion devices while simultaneously maintaining good core plasma purity and confinement.
The collaboration between Dr. Sergei Kracheninnikov in our group, the Nagoya University NAGDIS-II linear simulator group led by Prof. Shuichi Takamura, and the Alcator C-Mod staff resulted in the first experimental observations of molecular activated recombination involving vibrationally excited molecules in a plasma simulator and a tokamak, respectively. Recombination is the mechanism that reduces the particle and heat load on the divertor target plates to acceptable levels. In addition, Dr. Kracheninnikov's insight that retaining transport across the magnetic field substantially widens the V shaped radiation front, thereby strongly enhancing radiation losses and allowing significantly higher input powers, has been confirmed by observations on ASDEX-U in Germany and C-Mod at MIT. Presently the group is leading efforts to i) understand the mechanisms at work just inside the separatrix, ii) improve radiation transport and neutral particle modeling, and iii) develop adaptive, unstructured grids necessary to effectively resolve radiation and ionization fronts in numerical modeling.
Advanced Tokamak Physics, MHD Stability, and RF Interactions
In this effort under the leadership of Drs. Paul Bonoli, Jesus Ramos, and Prof. Miklos Porkolab, a state of the art simulation code has been developed to compute self-consistent MHD equilibria in the presence of non-inductively driven currents. These equilibria are then analyzed for ideal MHD stability using a numerical equilibrium and stability code. Such studies are of great importance in the C-Mod program since they offer a means to improve tokamak performance, ultimately leading to an attractive steady state reactor. These so-called advanced tokamak operating modes are characterized by relatively high fractions of non-inductive bootstrap current (approximately 75%) and non-monotonic (''reversed shear'') profiles of the safety factor. Such a reversed shear mode of operation in steady state has been identified for Alcator C-Mod using a combination of on-axis current drive in the ion cyclotron range of frequencies (ICRF) and off-axis lower hybrid current drive (LHCD) or mode converted ion Bernstein waves (IBW). The numerical model used in this work was developed by Dr. Marco Brambilla at the Max Planck Institute in Garching, Germany and was implemented at MIT. This current drive technique will be tested in the coming year on C-Mod using a new four strap ICRF antenna. These techniques will be used to optimize the expected performance of a "Next Step Burning Plasma Experiment" that may be designed by the world fusion community.
Reversed Field Pinch Theory
In another area, work was completed on an analysis of energy transport in a reversed field pinch (RFP) fusion configuration (with graduate student Antonio Bruno and Professor Jeff Freidberg). By assuming that the magnetic field and pressure profiles relax to a state which is marginally stable to the Suydam criterion (because of the related MHD turbulence) they derived an expression for the energy confinement time. This expression is in exact agreement with the empirically determined scaling law obtained from various RFP data .
RFD Theory and Basic Plasma Theory
The Plasma Theory Group under the direction of Prof. Abraham Bers and Dr. Abhay K. Ram has continued work on their proposed new means of plasma heating and current drive in the National Spherical Tokamak Experiment (NSTX), first reported in last year's President Report. Coupled analytical and computational work has shown that in a range of frequencies from 14 to 18 GHz more than 70% of the external power incident in the extraordinary wave can be mode-converted to electron-Bernstein waves (EBW) in the core of the plasma; EBW deposit their energy locally and efficiently on electrons. Basic studies of coherent and chaotic wave-particle interactions, carried out by this group, have lead to discovering new means for heating ions in a magnetic field by two lower hybrid waves, which is much more effective than the usual single wave heating. The frequencies of the two waves have to be separated by a multiple (1,2, or 3) of the ion-cyclotron frequency, and their wavenumbers have to be close in magnitude. Appropriate choices of the wave parameters can also be made to lead to energy extraction from energetic ions, such as from fusion produced alpha-particles. Also ongoing in this group are studies of nonlinear wave-wave interactions relevant to laser-plasma systems for inertial confinement fusion, and in collaboration with the laser-plasma group at the Los Alamos National Laboratory. In particular, a new model for the saturation of stimulated Raman scattering, which invokes coupling to spatiotemporal chaos in the excited Langmuir decay, has been shown to predict some experimental observations of light backscattering form laser produced plasmas.
PLASMA PHYSICS EXPERIMENTS
Levitated Dipole Experiment
During FY98 we began the design of a new fusion research facility, the Levitated Dipole Experiment (LDX). The LDX represents a new concept exploration experiment funded by the DoE as a joint collaborative project with Columbia University. The LDX facility is being designed by the engineering division of the PSFC and it will be located within the Tara cell in NW21. We envision a 5 year research program and the first plasma results are expected in the spring of 2001. The levitated dipole experiment represents a new and innovative approach to magnetic fusion which will utilize a levitated superconducting coil to confine plasma in a dipole magnetic field. The principal investigators of this project are Dr. Jay Kesner of the MIT Plasma Science and Fusion Center and Professor Michael Mauel of Columbia University.
The project includes a 5 year funding period with an approximate budget of $1 million per year, (shared between MIT and Columbia University). The construction of the project will be directed by Dr. Minervini during the initial 2 1/2 year period and a substantial fraction of the FY98 and FY99 budget will go to the PSFC engineering division for the design and fabrication of the facility.
Ionospheric Plasma Research
The Ionospheric Plasma Research Group (Dr. Min-Chang Lee and students) have been conducting laboratory experiments on the Versatile Toroidal Facility (VTF) at PSFC and ionospheric plasma heating experiments at the Arecibo Observatory (Arecibo, Puerto Rico). These experiments, aimed at investigating wave-plasma interactions and plasma turbulence, can effectively cross-check the results obtained in tenuous space plasmas and dense laboratory plasmas. The most important research results in the past year are the discoveries of RF-excited ionospheric plasma bubbles and sheet-like plasma density striations(reported by Lee et al. in the Geophysical Research Letters) In a different area of research funded by DoD's Defense University Research Instrumentation Program (DURIP), a portable radar system will be purchased this year. This broad-band radar will be used as a diagnostic instrument for ionospheric plasma heating experiments, and as new RF sources for VTF laboratory experiments.
Basic Physics Experiments on the Versatile Toroidal Facility (VTF)
Professor Ambrosio Fasoli has been appointed the leader of the VTF toroidal facility. He will establish a new program in basic experimental plasma physics, transferring much of the equipment from Versator II in the Research Laboratory of Electronics (RLE).
Inertial Confinement Fusion Experiments
Recent work of the MIT, Univ. of Rochester, and LLNL collaboration (Dr. Richard Petrasso and coworkers) has resulted in the first spectroscopic measurements of energetic charged particles on the Omega inertial fusion experimental facility. Individual line profiles of charged fusion products have been obtained, and include D-3He protons (14.7 MeV), D-3He alphas (3.6 MeV), D-T alphas (3.5 MeV), D-D protons (3.0 MeV), and D-D tritons (1.0 MeV). Knockon tritons and deuterons have also been observed and quantified. From these different particle measurements, the first ever obtained on an inertial confinement device, it has been possible to determine fusion yields, ion temperatures, fuel and ablator core conditions (i.e. Rs), and anomalous accelerations. Such parameters are crucial to understanding the dynamics of the implosion process. In addition, surprising and copious fluxes of energetic ablator proton "lines" have been observed from ~ 100 to ~ 700 keV. The endpoint energy of these ablator protons suggest that the capsule is sometimes charging up to ~ 700 kV. This result was quite unexpected.
At the end of July a second large spectrometer, again the result of the MIT, Univ. Rochester, and LLNL collaboration, will be interfaced to Omega. In addition to the previous measurements, the two spectrometers working in tandem will be able to make detailed determinations of implosion symmetry. Both spectrometers are prototypes of a set which MIT and collaborators are in the process of designing for the National Ignition Facility (NIF). The NIF will be the first facility in the world to achieve ignition, and we expect the MIT spectrometers to play a prominent role in this national facility and the achievement of ignition.
Phase Contrast Imaging on DIII-D
This collaborative effort between General Atomics and MIT (Professor Miklos Porkolab) has enjoyed a new period of 3-year funding cycle. Through careful studies over the course of several years, the properties of edge turbulence have been mapped out by Dr. Coda, a former MIT physics graduate student. The novel observation of the existence of radially propagating modes has been found to be in agreement with recent analytical and numerical code predictions on the global structure of a class of plasma instabilities (ITG modes). For his pioneering studies, Dr. Coda won the 1997 APS Division of Plasma Physics Outstanding Thesis Award in November, 1997. Two new post doctoral fellows, Dr. Peter O'Shea and, very recently, Dr. Chris Rost have been upgrading the experimental installation to comply with new safety regulations, and will continue the experiments in the next fiscal year.
Gyrotron Scattering Experiments on JET
A collaborative effort with the European community to develop and utilize a unique advanced fusion plasma diagnostic capability for highly energetic ions inside the plasma core is expected to continue next year. A successful demonstration of high-power collective Thomson scattering from energetic ions was achieved this fiscal year with MIT participation (Drs. Paul Woskov and John Machuzak) on the JET tokamak in England. A 100 - 400 kW millimeter-wave Russian gyrotron was used with a sensitive heterodyne receiver to obtain scattered millimeter-wave signals from radio frequency heated minority helium species in the core plasma of a tokamak for the first time. Planning is currently under way to either continue this work at JET or to temporarily pursue additional experimentation at the TEXTOR tokamak in the Netherlands.
WAVES AND BEAMS DIVISION
The Waves and Beams Division, headed by Dr. Richard Temkin, conducts research on novel sources of electromagnetic radiation and on the generation and acceleration of particle beams.
The gyrotron is a novel source of microwave, millimeter wave and submillimeter wave radiation. Gyrotrons are under development for electron cyclotron heating (ECH) of present day and future plasmas as well as for high frequency radar. These applications require tubes operating at frequencies in the range 100-300 GHz at steady-state power levels approaching 1 MW. The gyrotron research group is led by Dr. Kenneth Kreischer. In 1998, research has concentrated on 3 major issues in gyrotron research: (i) increasing the power output of gyrotrons, (ii) producing nearly perfect Gaussian microwave beams, and (iii) increasing the efficiency of gyrotrons. Progress in these areas requires investigating the physics issues, including mode competition and beam quality, of high power, high frequency gyrotrons. A prototype experiment at M. I. T. has been built and has demonstrated a power level of 1.5 MW at a frequency of 170 GHz with an efficiency of over 35%. A novel mode converter for this gyrotron has been built and tested. A first attempt at this technique was recently tried at Communications and Power Industries of Palo Alto, CA. The result is an excellent Gaussian beam that is passed through a low loss, diamond window. Future work will concentrate on increasing the efficiency of the gyrotron to close to 70% using depressed collectors. A program of research is also underway to demonstrate a 140 GHz coaxial cavity gyrotron. The coaxial cavity gyrotron may be capable of higher power than conventional cavity gyrotrons, up to 3 MW. A new idea for a gyrotron microwave window, a dome shaped window, is also under investigation. This research is primarily sponsored by MIT Lincoln Lab through their Advanced Concepts Committee (ACC) internal funding program. First pressure tests of the window were completed and are being analyzed. A new research program has been initiated to develop a 250 GHz gyrotron for use in electron spin resonance and nuclear magnetic resonance studies. This research, funded by NIH in collaboration with Prof. R. Griffin of the Magnet Lab, is a pioneering effort in high frequency spin resonance studies. The first equipment for this experiment has been built and is under test.
HIGH GRADIENT ACCELERATOR RESEARCH
The High Gradient Accelerator Group is conducting research on a novel, 17 GHz, microwave driven, photocathode electron injector. This device, sometimes called an RF gun, can generate a 2 ps beam of 1-2 MeV, 50-500 A electrons at high repetition rate. A 26 MW, 17 GHz klystron power source drives the electron gun. This electron beam can be used for microwave generation or it can be used as an injector into a 17 GHz, high gradient accelerator. This research supports the program to build new electron accelerators that can reach the TeV range of energies.
In 1998, the RF gun was operated and the beam output energy and energy spread were measured. This is the first photocathode electron gun to operate at a frequency above 2.856 GHz. Conditioning of the cavity allowed operation of the gun at surface fields of up to 250 MV/m before dark current and breakdown were observed. Using 10-20 uJ, picosecond pulses from a Ti:sapphire laser tripled to 267 nm, electron bunches of 0.1 nC were obtained with energies exceeding 1 MeV. In 1998, we installed a high gradient accelerator built by Haimson Research Corp. This accelerator can achieve beam energies of about 30 MeV. This research should establish 17 GHz as a feasible frequency for future TeV electron colliders.
The Intense Beam Theoretical Research Group, led by Dr. Chiping Chen, has contributed significantly to our understanding of coherent radiation generation and particle acceleration. Topics covered include coherent radiation sources (CARM, FEL, gyrotron, relativistic klystron, relativistic TWT), intense beam transport and beam halo formation, beam-beam interactions, cyclotron resonance accelerators, two-beam accelerators, photocathode design, and other topics. Research explores self-field-induced nonlinear resonant and chaotic phenomena in intense charged particle beams. This research supports the U. S. program to construct advanced accelerators for such applications as nuclear waste treatment, heavy ion fusion and free electron lasers.
PLASMA TECHNOLOGY DIVISION
The mission of the Plasma Technology Division led by Drs. Daniel Cohn and Paul Woskov, is to develop new plasma technology applications with particular emphasis on environmental applications; to develop new fusion diagnostics; and to develop new fusion system concepts.
The Division is developing microwave plasma spectrometer systems for continuous monitoring of metals emissions from plasma furnaces, incinerators and other technologies for treatment of waste at DoE sites. The microwave plasma spectrometer approach has unique capability for meeting DoE needs of real time in situ measurements. The Division is also developing plasma technology for conversion of hydrocarbon fuels into hydrogen rich gas. It is investigating the use of plasma produced hydrogen-rich gas for pollution reduction in both stationary power and vehicular applications. Application to pollution reduction from internal combustion engines could have an important impact on air quality. In addition, plasma conversion of difficult to use biofuels into readily usable clean combustion fuels is being investigated.
During the last year substantial progress has been made in developing a real time calibrated microwave plasma continuous emissions monitor for hazardous metals. A field test was successfully carried out at the U. S. Environmental Protection Laboratory in Research Triangle Park, North Carolina. In the area of plasma generation of hydrogen rich gas, a major improvement in conversion efficiency and in electrical power requirement has been achieved. In addition, initial experimental studies of plasma conversion of biofuels have produced promising results.
During the next year, improvements will be made in the performance of the real time calibrated microwave plasma continuous emissions monitor. This work will include novel studies of atmospheric microwave plasmas. In the area of plasma generation of hydrogen-rich gas, a new program is underway to investigate vehicular applications. This program will be funded by the DoE Office of Transportation Technologies and will be carried out in collaboration with Battelle Pacific Northwest National Laboratory.
Paul Woskov has been notified that he will receive a 1998 R&D 100 award. The Award will given for development of the real time calibrated continuous emissions monitor. Dr. Woskov, Dr. Dan Cohn and other members of the Plasma Technology Division have also received R&D 100 Awards in 1994, 1995, and 1997.
TECHNOLOGY AND ENGINEERING DIVISION
The Technology and Engineering, headed by Dr. Joseph Minervini, conducts research on conventional and superconducting magnets for fusion devices and other large scale power and energy systems.
During the past year the major emphasis of the Division's effort has been on completing the Central Solenoid Model Coil (CSMC) as one of the major R&D tasks of the ITER Engineering Design Activity (EDA). This work has been carried out both through subcontracts to industry, with Lockheed Martin being the prime contractor, and through coil fabrication activities by engineers and technicians from the Technology and Engineering Division and from the Alcator Division, in an MIT-leased facility in Hingham, MA. When completed by end of the current fiscal year, the CSMC will be the world's most powerful superconducting pulse magnet, storing 650 MJ of energy at the design field of 13T.
Other activities within the Division included operation of the Pulse Test Facility (PTF), a unique, large bore magnet facility, specifically built under the ITER program, to test large size superconducting cable-in-conduit conductors and joints under pulsed field conditions. During the PTF's most recent test campaign, a prototype conductor and joint -- designed and fabricated by our staff -- was successfully tested to meet the operating requirements of the CSMC. Although scheduled to test at least one additional superconductor sample provided by Japan, the facility operations were stopped halfway through the fiscal year to conserve funds for continued CSMC construction.
Other major Division activities included completion of a materials database on the new superalloy Incoloy Alloy 908 in the Materials Laboratory of the Technology and Engineering Division under the leadership of Prof. Ronald Ballinger. This alloy was specifically developed by Prof. Ballinger and INCO Alloys International (Huntington, WV) to enhance the performance of Nb3Sn superconductors when used in a cable-in-conduit conductor configuration. During the ITER CSMC fabrication program, over 60 tons of this material was commercially produced in extruded cross-section and welded form, and it provides the major structural component of the CSMC.
Another active area of research was performed under sub-contract to the Princeton Plasma Physics Laboratory for magnets and magnet systems design for the Korean K-STAR superconducting tokamak program. Additional supporting superconductor R&D was performed under direct contract to Samsung Advanced Institute of Technology.
In related research activities, Dr. Jeffrey Freidberg and his colleagues have developed an elegant method for mapping the magnetic fields in the large detectors located in high energy particle accelerators (with Drs. Stefano Migliuolo, Ali Shajii, Jay Jayakumar). The method makes extensive use of Green's theorem and the theory of integral equations to greatly reduce the cost and time of traditional volume mapping techniques to a much simpler surface mapping procedure. The procedure is now being implemented on the PHENIX detector of the RHIC facility at Brookhaven.
Work continues on developing a continuum model of a multistrand superconducting CICC magnet in order to explain the ramp rate limitation observed in certain coils (with graduate student Michael Thomas and Dr. Joseph Minervini). This is a significant modeling effort attempting to account for transverse geometric effects in cables with as many as 1000 strands with time varying transport current and transverse fields.
Development work also continues on a procedure for determining pipe thickness from a series of external impedance measurements (with graduate student Julio Rangel and Prof. Ron Ballinger). Such a procedure would be of great safety value and economic importance to the nuclear power industry where steam pipe thinning due to corrosion is a critical problem. The new procedure saves time (i.e. money) by allowing continuous monitoring of pipe thickness without the need for shutdown as is the current practice.
Overall funding became constricted during fiscal year 1998, which resulted in layoff notices being issued to 4 research staff members, and 5 regular and 2 temporary technicians. In addition 1 research staff member and 1 postdoctoral associate left for industry positions and were not replaced. Severe reduction in funding expected for ITER in the post-EDA period, combined with the cost overrun for the CSMC, indicates that fiscal year 1999 funding will not be sufficient to maintain the Division at it's already reduced size, so additional layoff actions are required. The Division supports 6 graduate students in the Departments of Nuclear, Mechanical, and Materials Science and Engineering. We are committed to maintain continuity of support for these students at least through FY99.
EDUCATIONAL OUTREACH PROGRAMS
The Plasma Science and Fusion Center's educational outreach program is planned and organized under the direction of Mr. Paul Rivenberg, Outreach and Public Relations Coordinator of the PSFC. The program focuses on heightening the interest of K-12 students in scientific and technical subjects. The PSFC seeks to educate local students and the general public by conducting general tours of experiments being done here. Special "Outreach Days" are held twice a year, encouraging high school and middle school students from around Massachusetts to visit the PSFC for a day of hands-on demonstrations and tours. This year these days attracted record numbers.
The Mr. Magnet Program, headed by Mr. Paul Thomas, Technical Supervisor, brings a traveling demonstration on magnetism into local elementary schools, inspiring and exciting students with the chance to take part in hands-on experiments with magnets. Over the past year he has worked with over 30,000 students at over 66 schools and other events. Since receiving the 1997 Billard Award from MIT, Paul Thomas has significantly increased his national visibility, traveling in his truck to Pittsburgh for the November, 1997 APS-DPP meeting, and to Washington, DC in April, 1998, to participate in a Plasma Expo (see below), also visiting area schools on both occasions. As the program has grown, Paul has increased the size and number of his demonstrations to help accommodate the now large auditoriums in which he works. His show has expanded to the point where we now need to seek funding for a larger truck for his demonstrations. The Department of Energy continues to be impressed with this program, and encourages more and more national outreach. We plan to seek funding from this agency for this and other PSFC educational programs.
The PSFC continues to work with other national laboratories to educate students and the general public. An annual Teacher's Day (to educate teachers about plasmas) and Open House (to which they can bring their students) has become tradition at each year's APS-DPP meeting. The 1997 event in Pittsburgh was the result of a year of planning involving the local education community and representatives from various laboratories. It attracted over 60 teachers to Teachers Day and 1,000 students/public to the Plasma Expo. PSFC Outreach Coordinator Paul Rivenberg was involved with the planning of this event, and heads MIT's leading organizational role in the 1998 APS meeting in New Orleans. Over 170 teachers have already applied for the 1998 Teachers Day, and we anticipate over 3,000 students at the Expo. The PSFC participated in a similar outreach event in March and April of 1998 in Washington, DC, sponsored by General Atomics and the Coalition for Plasma Science (CPS).
The Coalition for Plasma Science is a growing organization formed by members of universities and national laboratories to promote understanding of the field of plasma science. Associate Director Dr. Richard Temkin, who oversees PSFC education efforts, is working with this group on goals which include requesting support from Congress and funding agencies, strengthening appreciation of the plasma sciences by obtaining endorsements from industries involved in plasma applications, and addressing environmental concerns about plasma science, particularly fusion. Tobin Smith of MIT's Washington Office has been Acting Chairman of the Coalition during this year. In June, 1998, the group presented" Plasma-Science and Technology for the 21st Century," a reception for congressional representatives and their staff, geared to educate them about the potential of plasma research. Many of the popular, interactive demonstrations used for this event were supplied by MIT's Mr. Magnet Program, and were transported to DC by Paul Thomas in his truck. Mr. Thomas Pedersen, a graduate student, and Mr. Paul Rivenberg, Outreach and Public Relations Coordinator, also made presentations at the Washington event.
APPOINTMENTS AND PROMOTIONS
During the past year, there have been several important appointments and promotions in Plasma Science and Fusion Center program areas.
Professor Ambrosio Fasoli, a new Assistant Professor in the Physics Department has joined the Plasma Science and Fusion Center. He was appointed leader of the VTF experimental program. Other appointments included Xavier Bonnin, Darren Garnier, Anders Odblom and Jon Christian Rost as Postdoctoral Associates in the Physics Research Division.
In the Office of Resource Management, Matthew Fulton was promoted to Facilities and Safety Coordinator. The Alcator Project promoted Stephen Wukitch to Leader, RF Experiments. The Fusion Technology and Engineering Division promoted Shahin Pourrahimi to Advanced SC Materials Group Leader.
During the past year there was one Institute promotion in the Plasma Science and Fusion Center, Dr. Richard Temkin, Associate Director.
During the past year, the following departments granted students degrees with theses in plasma fusion and related areas:
Electrical Engineering and Computer Science: Michael Rowlands, M.S.; and Kenneth Wu, M.S.
Nuclear Engineering: Allen Aaron, M.S.; Shaun Meredith, M.S.; George Miller, M.S.; John Novak, Ph.D.; Jeffrey Schachter, Ph.D.
Physics: William Daughton, Ph.D.; Darin Ernst, Ph.D.; Wen Hu, Ph.D.; Jon Christian Rost, Ph.D.
We take this opportunity to wish these graduates success in their future professional endeavors.
More information about the Plasma Science and Fusion Center can be found on the World Wide Web at the following URL: http://www.pfc.mit.edu/
MIT Reports to the President 1997-98