MIT Reports to the President 1999–2000
The Plasma Science and Fusion Center (PSFC) is recognized internationally as a leading laboratory in developing the scientific and engineering aspects of magnetic confinement fusion and conducting cutting-edge research in plasma science and related technology. Research at the PSFC is carried out in 5 primary areas:
The Plasma Science and Fusion Center Research and Development programs are supported principally by the Department of Energy’s Office of Fusion Energy Sciences. There are approximately 247 personnel associated with PSFC research activities. These include: 16 faculty and senior academic staff, 49 graduate students and 4 undergraduates, with participating faculty and students from Electrical Engineering and Computer Science, Materials Science and Engineering, Mechanical Engineering, Nuclear Engineering, and Physics; 67 research scientists, engineers and technical staff, 59 visiting scientists and engineers, postdoctoral associates and research affiliates, 29 technical support personnel; and 23 administrative and support staff.
PSFC’s funding decreased in fiscal year 2000 by about 18% over fiscal year 1999 from $31.5 million in fiscal year 1999 to $25.9 million. This decrease had been anticipated with the completion of the DOE-funded ITER Program. For fiscal year 21001 we expect flat (or slightly decreased) funding, depending on the outcome of the final congressional budget for DOE.
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 field 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, four faculty members and 18 graduate students. Recently, C-Mod has become a National User’s Facility, and as such, the total C-Mod project funding is supplemented by approximately 20% by way of non-MIT collaborators. Substantial ongoing 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. Direct funding to MIT grew to $15.2 million in fiscal year 2000 (an increase of $0.8 million) as a consequence of having obtained approval of the 3 year, $4.2 million new lower-hybrid upgrade to C-Mod. Funding for the upgrade is to be shared with the Princeton Plasma Physics Laboratory.
There are four 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. Plasma boundary 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 not only for research into wave absorption and heating processes but also for profile control via mode conversion processes and associated current drive mechanisms. Advanced tokamak research in the future on C-Mod proposes to demonstrate fully relaxed current profile control and sustainment through efficient off-axis current drive by radio waves in the lower hybrid range of frequencies.
Plasma transport is dominated by turbulence under most conditions but often radially-localized regions of reduced transport, "transport barriers" occur. In these regions turbulence is suppressed and steep density or temperature gradients occur together with strong radial electric fields. These barriers are of intrinsic scientific interest but also great importance as a method of improving confinement. Alcator C-Mod has implemented measurements of unprecedented spatial resolution of the H-mode barrier which constitutes the sharp edge of the plasma. We have also begun studies of internal barriers induced by a variety of techniques.
Plasma rotation is an important ingredient of the transport problem both because it reveals important basic information about transport processes and because it is believed to cause the turbulence suppression in transport barriers. C-Mod’s unique role in rotation studies is that it has no internal momentum sources and so presents a ‘pristine’ transport test-bed for momentum transport.
Divertor studies using C-Mod’s dynamic gas bypass control have led to a new view of the processes determining the level of neutral pressure in the divertor chamber; namely that it adjusts itself to keep the bypass throughput approximately constant. This observation is important for planning future divertor pumping and closure. Edge studies are increasingly focusing on understanding how the plasma behavior varies from the closed to the open magnetic flux surfaces, in other words the transition across the separatrix.
Ion cyclotron radio frequency (ICRF) power on C-Mod was almost doubled to the 7 MW level through the addition of 4 MW of tunable power in the 40-80 MHz range and a four strap antenna (a collaboration with Princeton Plasma Physics Laboratory). These major upgrades will make it possible to explore rf wave absorption and tokamak confinement physics near the ideal MHD beta-limit. Mode conversion from fast Alfven waves to short wavelength Bernstein waves are also being explored and mode conversion current drive experiments will be performed using the new phaseable four strap antenna built at Princeton. Detailed comparisons between ICRF theory and experiment are being carried out using a state of the art full wave electromagnetic field solver (the TORIC code) that was implemented at MIT through a collaboration with the Max Planck Institute for Plasma Physics (Germany).
This past year we received approval from DOE for the addition of a new RF system to C-Mod, namely, a 3 MW, 4.6 GHz lower-hybrid microwave system. The addition of 3 MW of off-axis lower hybrid current drive power will make it possible to operate the tokamak near the ideal MHD beta limit at somewhat reduced fields with purely noninductively maintained current profiles. A significant fraction (60—70%) of the total current in these discharges will be generated by "bootstrap" effects and the auxiliary heating will be supplied by 5 MW of ICRF heating power at 80 MH and 60 MHz. The ultimate goal of these experiments is to demonstrate control of the current profile and sustainment of high MHD beta limits in the presence of steep transport barriers and fully related current profiles. A detailed theoretical modeling program has been carried out for several years, and its results have clearly shown C-Mod’s excellent potential to carry out these "Advanced Tokamak" types of experiments. This program will ensure a vigorous research program on Alcator for at least the next 5 years.
The Physics Research Division, headed by Professor Miklos Porkolab, seeks to develop a theoretical and experimental understanding of plasma physics and fusion science. This division is also a base for developing basic plasma physics experiments, new confinement concepts, novel inertial confinement fusion diagnostics and space plasma physics experiments. In addition, this division is also the home for a strong base and supporting theory program.
The Plasma Edge and Core Transport and Turbulence Theory Group (Drs. Dieter Sigmar and Peter Catto, and visiting scientist Jim Hastie) goals are to understand plasma and neutral particle turbulence, transport, and stability effects in plasma science experiments. The research relies on analytic and numerical investigations, as well as experimental observations from Alcator C-Mod and other tokamaks; and includes theoretical support for the Levitated Dipole Experiment (LDX) being built at the PSFC in collaboration with Columbia University. The two most significant results of our research during the past year are a demonstration that wave driven parallel current can be generated in a tokamak in the absence of parallel momentum input via wave-particle interactions if collisions are retained; and proof that the finite plasma pressure equilibrium confined by a point dipole magnetic field is magnetohydrodynamically stable as long as the pressure is nearly isotropic.
In this research area, state of the art simulation codes have been developed (Drs. Paul Bonoli and Jesus Ramos and Prof. Miklos Porkolab) and used to compute self-consistent MHD equilibria in the presence of non-inductively driven currents. These studies form the basis of a proposed major upgrade to the Alcator C-Mod tokamak involving the addition of off-axis lower hybrid current drive power (up to 3 MW) and 5 MW of ion cyclotron resonance heating power. This will allow C-Mod to explore stable modes of operation near the ideal MHD beta limit. These so-called advanced tokamak operating modes are characterized by enhanced confinement regimes, high fractions (approximately 70%) of non-inductive "bootstrap current" (self generated toroidal currents by finite plasma pressure), and non-monotonic current profiles. The most recent efforts have concentrated on modeling pressure and current profiles that are expected to arise as a result of transport barriers.
A significant new research result achieved in this area during the past year was the simulation of mode converted ion Bernstein waves (IBW) in toroidal geometry using a full-wave ICRF electromagnetic field solver. This code was developed at the Max Planck Institut fur Plasmaphysik in Garching by Dr. Marco Brambilla and was implemented at MIT by Dr. Paul Bonoli through a collaboration. Model predictions for electron heating by these mode converted waves were found to be in close agreement with experimental data from the Alcator C-Mod tokamak. Computations of this type push non-parallel supercomputing technology to its limit in terms of code memory requirements. However efforts are now underway to implement the field solver on a massively parallel platform (MPP).
Under the leadership of Prof. Abraham Bers and Dr. Abhay K. Ram, theoretical and computational work has resulted in a number of accomplishments. A study of RF current drive in the presence of bootstrap current–of importance to the steady-state operation of tokamak fusion reactors–has been completed and submitted as the Ph.D. thesis of Mr. Steven D. Schultz. At high fractions of bootstrap current, a synergism between bootstrap current and RF current drive is found to be significant. A new study has been initiated to evaluate the emission from electron Bernstein waves as a means for measuring the electron temperature in high-beta plasmas such as the National Spherical Tokamak Experiment (NSTX). Experiments addressing this are being carried out by the members of the NSTX team at the Princeton Plasma Physics Laboratory.
Computational model studies have been carried out to explain the observed effects of ion-acoustic wave damping on the saturation of stimulated Raman scattering (SRS) in intense laser-plasma interactions. Reducing light reflectivity due to SRS is of crucial importance to the success of efficient inertial fusion energy generation with lasers. Studies have also been initiated on laser-plasma interactions in a single hot spot in collaboration with the Los Alamos National Laboratory (LANL) experiments on TRIDENT. A graduate student will participate in these experiments at LANL. Finally, studies on nonlinear energization and de-energization of plasma ions by multiple waves in a magnetic field has received new funding by a joint NSF-DOE basic plasma studies program.
The Levitated Dipole Experiment (LDX) represents a new concept exploration experiment funded by the Department of Energy. LDX is a joint collaborative project with Columbia University and it will be located in NW21 at MIT. The principal investigators of this project are Dr. Jay Kesner of the MIT and Professor Michael Mauel of Columbia University. The LDX facility is being designed by the engineering division of the PSFC under the leadership of Dr. J. Minervini. The project has been funded as a 5 year grant, with a budget of $1.5 Million for fiscal year 2000 (shared between MIT and Columbia University). The construction of the project will take place during the initial 3 1/2 year period and a substantial fraction of the fiscal year 1998—fiscal year 2000 budget will go toward the design and fabrication of the facility.
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 concept was inspired by observations that high pressure plasmas can be confined by planetary dipole magnetic fields, such as the magnetosphere which surrounds Jupiter. Compared with the traditional fusion approaches the levitated dipole may permit the confinement of higher pressure plasmas with reduced cross-field transport.
The design of the facility was largely completed during fiscal year 1998 and we are now in the construction phase. The vacuum chamber is in place in the Tara cell of NW21 and the high performance Nb3Sn coil has been successfully tested. The first plasma results are expected in the summer of 2001. When completed LDX will be the only superconducting magnetic confinement experiment in the U.S. fusion research program.
The basic experimental plasma physics group, led by Prof. A.Fasoli, is concentrating its efforts on the general issue of magnetic reconnection, i.e. the link between the plasma dynamics and changes in the magnetic field structure. Reconnection determines the sun corona heating (solar flares), the interaction between the solar wind and the earth magnetic field (aurora) and, in fusion devices, fast relaxation processes that can influence dramatically the plasma confinement. The construction of the apparatus to study magnetic reconnection has been completed, mostly using pre-existing facilities at the MIT-PSFC. Collisionless plasmas of interest for magnetic reconnection studies are now routinely produced in the Versatile Toroidal Facility, VTF, by electron cyclotron resonance heating. Reconnection is driven by applying a toroidal electric field perpendicular to the poloidal magnetic cusp field, thereby producing a radial plasma drift into the magnetic null point. The link between the change in magnetic topology and the particle dynamics is studied by combining measurements of particle flow velocities and distribution functions with those of the evolution of the magnetic field structure and of plasma fluctuations. The diagnostic systems to perform these investigations are being installed mainly with the help of a post-doctoral fellow and students.
Professor Fasoli has recently been selected for the Junior Faculty Development Award by the DoE’s Office of Fusion Science, with funding starting this fall at a level of about $170,000 per year for three years.
The collaboration with the world's largest magnetic confinement device, the Joint European Torus, at Oxford (UK), conducted by Prof. A.Fasoli and "on-site" post-doctoral fellow Dr. Ducio Testa, continues to produce new experimental results on the physics of plasmas close to fusion reactor conditions. The issue of the stability of Alfven waves in the presence of fusion produced 3.5 MeV alpha (a ) particles was studied. A new mechanism for the stabilization of the a -driven instabilities was discovered by comparing the measured damping rates of externally excited Alfven modes with the results of numerical simulations based on the plasma kinetic model. This mechanism is based upon mode conversion of the global Alfvén waves into locally absorbed kinetic modes. Fundamental nonlinear wave-particle physics was also explored at JET. We observed for the first time the strongly nonlinear regimes predicted by the general theory of near-threshold kinetic instabilities, with chaotic and explosive behavior for both waves and particles. The extension of the external wave driving technique to low frequency magnetohydrodynamic modes led to a method to diagnose the plasma proximity to instability limits, to be used in real-time to control the plasma so as to avoid macroscopic instabilities leading to major disruptive events. The implementation of this technique on the two largest US tokamaks, DIII-D at General Atomics and Alcator C-Mod at MIT, is now being explored.
MIT’s effort in inertial confinement fusion, led by Dr. Richard Petrasso and co-workers, has continued to produce exciting results on experiments conducted at the OMEGA laser facility at the Laboratory for Laser Energetics at the University of Rochester. MIT has been responsible for designing and implementing two very large charged-particle spectrometers. This work is a collaboration with the University of Rochester and Lawrence Livermore National Laboratory.
In order to understand the dynamics of the implosion process, the spectrometers are used to detect charged fusion products that are generated at the core of the imploding capsules. From the number of such reactants (i.e. the yield), the effectiveness of the fusion process can be determined. And from the energy loss of the reactants, as they pass through the capsule, a measure of the plasma containment can be determined. Both these quantities, yield and plasma containment, are fundamental parameters needed to characterize the quality of the implosions. In addition, since the spectrometers view the implosion from nearly 90 degrees apart, the implosion symmetry can be sensitively studied.
These spectrometers are prototypes for those being designed by MIT and collaborators for the National Ignition Facility (NIF) at Lawrence Livermore. In concert to these plans at the NIF, MIT organized and led the Basic Science Users Group for the NIF. This was a three-day workshop, held in Pleasanton, California, with 175 participants from the US, Japan, France, Germany, Canada and Japan. Extensive discussions and presentations were made on those areas of fundamental science–astrophysics, materials science, hydrodynamics, radiative sources and properties, plasma physics–that can be addressed at the NIF. For example, at the core of NIF implosions, we expect to achieve plasma densities that are 6 times larger than the density at the center of the Sun, or 52 times more dense than gold.
The development of fusion energy diagnostic technology is an ongoing effort at the PSFC. In one initiative, PSFC and General Atomics (GA) have collaborated for several years now on Phase Contrast Imaging (PCI) on the DIII-D tokamak at GA. Presently the experiments are being carried out by an MIT post-doctoral associate, Dr. Chris Rost on site at General Atomics. Through careful study over time, properties of edge turbulence in plasmas are being mapped out. The goal is to better understand improved plasma confinement regimes through a reduction (or elimination) of edge plasma turbulence. In another area, gyrotron scattering experiments (Dr. Paul Woskov and coworkers) have been completed on JET. Results obtained on JET verified the viability of this technique to detect the distribution function of energetic ion tails in the presence of intense RF heating. A new project has been initiated last year by way of a new 3-way collaboration among U.S., Dutch, and German scientists on the TEXTOR tokamak in Jülich, Germany. Continuation of this experiment is expected for the foreseeable future.
Visiting Professor Min-Chang Lee and his students successfully tested PSFC’s portable HF/VHF radar at Millstone Hill, Massachusetts during June 12—July 21, 2000, with frequency licenses issued by the federal government. Recently space plasma experiments in Massachusetts, Alaska and Puerto Rico have been scheduled for this group, aimed at the study of plasma turbulence which occurs naturally, or as the consequence of injected radio wave-plasma interactions in space. PSFC’s Ionospheric Radar Integrated System (IRIS), including the portable radar, a digital ionosonde, and two student-built VLF receiving systems will be used for ground-based space plasma diagnostics. The radar transmitters, operating in the frequency range of 10—60 MHz, will provide new rf sources for Professor Lee’s group to conduct laboratory simulation experiments, using PSFC’s Versatile Toroidal Facility (VTF). These field and laboratory experiments will improve the understanding of space plasma turbulence/space weather and enhance radio communication capabilities.
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. Besides the able assistance of Principal Research Scientist Dr. Ken Kreischer, this Division has a very substantial graduate student involvement in its research program.
The gyrotron is a novel source of microwave, millimeter wave and submillimeter wave radiation. Gyrotrons are under development for electron cyclotron heating (ECH) of plasmas in magnetically confined fusion experiments, as well as for high frequency radar. These applications require tubes operating at frequencies in the range 90-300 GHz at power levels of up to several megawatts. Dr. Kenneth Kreischer leads the gyrotron research group. In CY2000, we have completed the design of a new gyrotron oscillator intended to operate at the 1 to 1.5 MW power level. When operated at the 1 MW power level, it will provide additional margin (50%) in safety and reliability for the gyrotron. Reliability of gyrotrons and related equipment was identified by the fusion community as a major issue in electron cyclotron technology development. The new gyrotron will be tested at both MIT and at an industrial vendor, Communications and Power Industries of Palo Alto, CA. The MIT device will operate in 3 ms pulse lengths while the industrial tube should be capable of continuous wave (CW) operation. Research challenges include operation of the gyrotron in stable, single-mode oscillation without mode competition; production of a high quality electron beam; achievement of high interaction efficiency in the resonator and achievement of very high overall efficiency (>50%) when operated with a depressed collector. Experiments will begin at MIT in 2001 and in industry in 2001 or 2002.
In gyrotron research, it is also critical to have a high efficiency mode converter that can transform the output mode of the gyrotron into a Gaussian beam in free space. In recent years, we have been studying the measurement of the phase distribution in microwave beams using a phase retrieval algorithm based on the measure field amplitude on a
series of planes. In 2000, a new approach has been explored to determine the phase distribution in the beam. This method uses the measured field amplitude on a series of planes but relies on calculated moments of the field amplitude to determine the parameters of a polynomial expansion of the spatial phase distribution. The method will be applied to design single mirror correctors for the gyrotrons at General Atomics in San Diego. 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. Dynamic tests of this window, at high pressure and temperature, have begun in 2000, following a successful static pressure test. Full test results are expected this year.
In research on a 250 GHz gyrotron for use in electron spin resonance and nuclear magnetic resonance studies, reliable operation for many hours was achieved this year with operation at CW power levels of up to 25 W and pulsed power levels of up to 100 W. This research, funded by NIH in collaboration with Prof. R. Griffin of the Magnet Lab, is a pioneering effort in high frequency electron spin resonance studies. Signal enhancements of sixty have been demonstrated in initial NMR experiments. Future work at 500 GHz is under analysis. In a new program which started last year, we have been funded as part of a DOD MURI consortium for Innovative Vacuum Electronics. We have begun research on a gyrotron amplifier at 95 GHz; photonic bandgap structures and novel cathodes. The 95 GHz amplifier is being constructed with first tests planned at 140 GHz using available equipment. A gyrotron amplifier with a confocal waveguide structure has been built and will be tested in the summer of 2000.
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, 17.1 GHz klystron power source drives the electron gun. The electron beam can be directly applied to microwave generation experiments 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 2000, the RF photocathode electron gun has been rebuilt with magnetic solenoidal focusing to achieve higher electron beam brightness. A new microwave power distribution system has also been installed to allow power to be sent to either the RF gun or the Haimson accelerator. The emittance of the electron beam has been measured to be 3 p mm mrad for a 50 pC electron bunch, close to a record high value of beam brightness. A new electron gun that can achieve higher electron beam energies, over 2 MeV, and higher beam quality has been designed and is being fabricated. The Haimson 17 GHz electron accelerator achieved first operation in CY2000 with a 17 MeV electron beam. This is the highest power accelerator on the MIT campus and the highest frequency stand-alone accelerator in the world. One potential application of this accelerator is in free electron laser research. Improvements to the 17.1 GHz klystron have been made in 2000 to secure reliable operation at power levels of at least 15 MW at 17.14 GHz. A photonic bandgap cavity has been built and tested for operation at 17 GHz. This novel structure may have advantages over conventional microwave structures. This research program 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 very 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 related 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. In 2000, a new Green’s function code was written and was applied to studies of self-fields in bunched electron beams. One result of this new theoretical work is a general prediction of the limiting beam current that can be transported in microwave devices including klystrons and traveling wave tubes. In collaboration with Ron Davidson and his research group at Princeton, a technique has been developed for ideal matching of heavy ion beams.
The objectives of the Plasma Technology Division, led by Drs. Daniel Cohn and Paul Woskov, are to develop new fusion spin-off applications, particularly in the environmental area; to develop new fusion diagnostics; and to develop new fusion reactor system concepts. A major thrust is in the area of plasma aided manufacturing of hydrogen. Hydrogen has potential environmental advantages as a fuel that can greatly reduce pollution from stationary electricity generating systems and from vehicles. There are two projects. One project investigates the use of plasmatron devices for manufacturing hydrogen for use in stationery fuel cell facilities, vehicle refueling stations and hydrogen production facilities. The other project is investigating the vehicular use of compact plasma boosted devices for onboard conversion of hydrocarbon fuels into hydrogen-rich gas. The hydrogen-rich gas would then be combusted in a conventional spark ignition engine. Using the hydrogen-rich gas as an additive to gasoline, large reductions in NOx, a major air pollutant, can be obtained. Onboard hydrogen from plasma boosted devices production can also be used in catalytic reduction of diesel engine exhaust. Plasma boosted fuel conversion technology could greatly reduce pollution from cars, trucks and buses in the relatively near term without substantial cost increases or inconvenience. Over the longer term, the technology could facilitate the use of difficult to use alternative fuels; one possibility is the use of greenhouse gas reducing bio-oils that could be produced from rapidly growing trees and crops. Future plans include an expanded program in collaboration with Professor John Heywood of the Mechanical Engineering department and the Sloan automotive laboratory. The Plasma Technology Division is also investigating the use of millimeter wave reflectometry and pyrometry for measurement of the properties of glass produced in vitrification of radioactive waste.
The Technology and Engineering (T&E) headed by Drs. Joseph Minervini and Richard Thome 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 testing the Central Solenoid Model Coil (CSMC) which was built as one of the major R&D tasks of the ITER Engineering Design Activity (EDA). During the past year, the Inner Module of the CSMC, developed in the US, was installed with the Outer Module, developed in Japan, at a special, large-scale test facility located at the Japanese Atomic Energy Research Institute (JAERI) in Naka, Japan. With strong on-site participation by T&E Division engineers, the coil was successfully tested to design operating conditions and beyond, both in steady state and pulsed operation. Daily electronic transfer of test data from the remote test site allows detailed analysis by Division staff at MIT. The CSMC is the world’s most powerful superconducting pulse magnet, storing 640 MJ of energy at the design field of 13T. It is also the world’s largest superconducting magnet using Nb3Sn superconductor. The successful operation of this magnet is an important milestone in the development of large-scale superconductors and has potential benefit for magnet and power applications beyond fusion.
Significant progress was achieved in development of the magnet systems for the Levitated Dipole Experiment (LDX). Fabrication of the Floating Coil (F-Coil) was completed and the coil was successfully tested in July 2000. This innovative coil uses state-of-art Nb3Sn wire in a novel cable-in-channel conductor design. The coil itself incorporates a unique method for internal quench protection by use of co-wound copper eddy-current heaters. The completely potted construction gives inherent structural integrity. Preliminary test results indicate the coil is highly stable with no signs of training and no quenching to 110% of rated current. This result was achieved even when ramped up at 10x the rated ramp rate. Major progress was also achieved in fabrication of the F-coil cryostat and the charging station. A sub-contract for the Charging Coil (C-Coil) was placed with the D.V. Efremov Scientific Research Institute of Electrophysical Apparatus in St. Petersburg, Russia. Division staff are responsible for monitoring and approving the design.
Collaboration with the American Superconductor Corporation continued under a Phase II SBIR, for development of high temperature superconductors (HTS) for fusion applications and for the design of an HTS levitation coil (L-Coil) for the Levitated Dipole Experiment at MIT. During the next year, MIT will complete the design of the L-coil, have it constructed and install it in the LDX facility. This will be the first application of HTS magnet technology to the US Fusion program.
The Division is providing engineering support to the Princeton Plasma Physics Laboratory in the evaluation of Next Step Options for the US Fusion Program and in the design of selected machines, specifically, the Fusion Ignition Research Experiment (FIRE). In this regard, the lead for the program and the physics assessment is based in Princeton and Dr. Thome leads the engineering effort from MIT. The Division provides a major role in the magnet system design, cryogenic system design, and structural design for the FIRE as well as systems level studies.
Other major Division activities included continuation of materials development on the new superalloy Incoloy Alloy 908 in the Materials Laboratory of the Technology and Engineering Division under the leadership of Prof. Ronald Ballinger. Another active area of research was performed under sub-contract to the Samsung Advanced Institute of Technology for magnets and magnet systems design for the Korean K-STAR superconducting tokamak program. The Division continued to play an important role in technology development of magnet systems and quadrupole magnet array design studies for the Lawrence Berkeley National Laboratory in support of the High Current Transport Experiment (HCX) and the Integrated Research Experiment, (IRE) which are the main elements of the US Heavy Ion Fusion Driver program, a major focus for Inertial Fusion Energy (IFE). During the past year, in addition to the design studies and quadrupole analysis, the Division tested two superconducting quadrupole coils fabricated in industry as Prototypes for the HCX, and performed data analysis of the coil performance.
MIT continued to provide analysis for the use of superconducting magnets for several advanced fusion devices including the NCSX stellarator being designed by Princeton Plasma Physics Laboratory, and a superconducting version of a spherical torus fusion reactor called Aires-SCST. These studies include developing critical current algorithms for BSSCO and YBCO high temperature superconductors. The Division continued it’s important role in design and development of quadrupole focusing magnets for the Advanced Hydrodynamic Facility (AHF) being designed at the Los Alamos National Laboratory. These large bore superconducting quadrupole magnets will serve as magnetic lenses for Proton Radiography imaging of test objects in real time.
The Division was the Research Institution for a NASA funded, Phase-I STTR, in collaboration with the Advanced Magnet Laboratory, Inc., a Florida based small business. The purpose of this research was to study the feasibility of an electromagnetic catapult, "MagLifter," to lower the cost of cargo delivery to space. The sled would be magnetically levitated above a guideway and propelled by a linear synchronous motor for ~2 mile to a speed of 600 mph before the first stage rocket would fire and launch the vehicle. MIT was responsible for the design of the superconducting magnetic levitation system. The Division will make a Phase II proposal during the next year to continue the design. We have already submitted another joint Phase-I STTR proposal to NASA to study a superconducting magnetic energy storage system (SMES) as a pulsed power source for the MagLifter launch concept.
A proposal was submitted to NIH for the development of a new device to separate blood components for therapeutic purposes by use of magnetic separation. Unfortunately the proposal was not funded in this round, but several reviewers gave sufficiently good scores to encourage resubmission of a modified proposal in the next funding round.
The Division’s primary source of DOE funding from the OFES magnetics program remains flat for fiscal year 2001, but the funding from a variety of other programs should allow maintenance of the present staffing level.
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 the PSFC laboratories. 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.
The Mr. Magnet Program, headed by Mr. Paul Thomas, is completing its eighth year of bringing lively demonstrations on magnetism into local elementary and middle schools. This past year Mr. Magnet presented the program to over 30,000 students at over 55 schools and other events, reaching students from Kindergarten through college freshmen. He makes a special effort to encourage girls to consider a science-related career. This year Paul Thomas traveled with his truckload of equipment to Washington, DC, at the request of the Department of Energy, to involve participants of the DOE National Science Bowl with his hands-on magnetic experiences. Closer to home, Mr. Magnet made a great impression at the Cambridge World’s Fair in Central Square (Spring 2000).
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 American Physical Society-Division of Plasma Physics meeting. Paul Rivenberg aided organizers of the 1999 education events in Seattle, and continues to work on national and international events scheduled for Quebec (October, 2000) and Washington, DC (Spring, 2001). Paul Thomas was able to attend the Seattle Open House with his large Van de Graff generator, a big hit with the students.
In Spring 2000 Mr. Rivenberg worked with Johanna Hardy of the MIT Washington Office on creating a "Summer Camp" for 5 winners of the DOE National Science Bowl. At this time he also began collaborating with the MIT Museum on an exhibit about plasma, to open in July or August 2000. Administrative Assistant Mary Pat McNally has been instrumental in developing graphics for PSFC and other departments participating in this "Thinkapalooza" exploration space.
The PSFC continues to be involved with educational efforts sponsored by the Coalition for Plasma Science (CPS), 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. This year CPS produced an excellent trifold about plasmas, explaining simply and graphically what plasmas are and where they are found in the universe and on earth. CPS also sponsored a well-attended congressional luncheon in Washington, DC, during which University of Alaska educator David Newman explored how the topic of plasmas can be used in the classroom to excite students about science. Paul Rivenberg has continued his duties as editor of the Coalition’s Plasma Page, a summary of plasma-related news items of interest to the media. He has created a new, livelier graphic design for the page. Mr. Rivenberg is also heading a subcommittee to create a web site to help teachers bring the topic of plasma into their classrooms.
During the past year, there have been several important appointments and promotions in Plasma Science and Fusion Center program areas. The Physics Research Division appointed Johan Frenje Postdoctoral Associate and Karyn Green Research Engineer. The Alcator Division promoted Montgomery Grimes RF Engineer, James Zaks Mechanical Engineer and Stuart Sherman Programmer. The Alcator Division promoted Gary Dekow Engineering Coordinator, James Rosati Operations Coordinator and David Terry Chief Electrical Engineer.
During the past year, the following departments granted students degrees with theses in plasma fusion and related areas:
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 http://www.pfc.mit.edu/.
Miklos Porkolab
MIT Reports to the President 1999–2000