Plasma Science and Fusion Center
Plasma Science and Fusion Center (PSFC) is known internationally as a leading university research center for the study of plasma and fusion science and technology with research activities in five major areas: magnetically confined plasmas in the development of fusion energy; the basic physics of plasmas including magnetic reconnection experiments on the VTF facility, new confinement concepts such as the Levitated Dipole Experiment (LDX), development of novel high-temperature plasma diagnostics, novel diagnostics of inertial fusion experiments, basic laboratory and ionospheric plasma physics experiments, and theoretical research; a broad program in fusion technology and engineering development that addresses problems in several areas (e.g., magnet systems, superconducting materials and system studies of fusion reactors); research into plasma-assisted conversion of hydrocarbon fuels into hydrogen and the development of environmental remediation techniques based on plasma technology; and the physics of waves and beams (gyrotron and high gradient accelerator research, beam theory development, nonneutral plasmas, and coherent wave generation).
The PSFC R&D programs are supported principally by the Department of Energy's (DOE) Office of Fusion Energy Sciences (OFES). There are approximately 248 personnel associated with PSFC research activities. These include: 18 faculty and senior academic staff; 43 graduate students and 11 undergraduates, with participating faculty and students from Aeronautics and Astronautics, Electrical Engineering and Computer Science, Materials Science and Engineering, Mechanical Engineering, Nuclear Engineering, and Physics; 73 research scientists, engineers, postdoctoral associates and technical staff; 49 visiting scientists, engineers, and research affiliates; 31 technical support personnel; and 23 administrative and support staff.
PSFC's research funding was $27.9 million in FY2003, up 6.5 percent from $26.2 million in FY2002. Of this increase over FY2002, $1.2 million went to the Alcator C-Mod program and contributed to an increase in the length of Alcator's FY2003 experimental campaign to 13 weeks in FY2003 vs. only 8 weeks in FY2002. Based on preliminary budget guidance from OFES, and depending on congressional appropriation, we estimate that PSFC's total funding in FY2004 will increase by 12.1 percent to $31.3 million. This follows a pattern in the last few years of increasing support for the national program by the government, with Alcator funding increasing the last few years as well. Meanwhile, we have just won a new 3-year grant for an NSF/DOE initiative for the VTF magnetic reconnection experiment, starting August 15, 2003.
With Congress approving the US's reentry into the International Thermonuclear Experimental Reactor (ITER) Program, it seems likely that the MIT-PSFC will become involved again in this multi-national collaboration to build and operate the world's largest fusion research experiment. The MIT-PSFC participated in this program between 1992 and 1999 when it built with the ITER partners a large superconducting central solenoid magnet intended to model ITER's full scale CS coil. The US subsequently withdrew from the program. While DOE will make $2.0 million available in FY2004 for US participants to reengage this program, significant new monies for additional ITER specific tasks may not be available until FY2006.
Alcator Division
The Alcator C-Mod tokamak is a major international fusion experimental facility. Effective July 1, Professor Ian Hutchinson, who has led the project since 1987, was appointed head of the Nuclear Engineering Department. He stepped down as project leader at that time, and Dr. Earl Marmar, formerly executive head, has been named as the new project head. Research on C-Mod continued during the past year in high-performance, compact magnetic plasma confinement. Experiments this year were carried out in the science topical areas of transport, wave-plasma interactions, boundary physics and magnetohydrodynamic stability, as well as in the integrated thrust areas of advanced-tokamak and burning plasma science.
C-Mod is recognized as one of three major US national fusion facilities. The C-Mod team includes approximately 6 faculty and senior academic staff, 2 postdoctoral fellows, 13 MIT staff scientists, 19 MIT graduate students, 25 engineers, and 25 technicians. In addition we have collaborators from around the world, bringing the total number of scientific users of the facility to about 160.
Facility operation for research this year totaled 54 days, which was 2 days more than the originally planned 13 weeks (@4 days/week), up from 8 weeks in FY2002. This successfully completes our level 1 DOE operations milestone for FY2003. The operations are largely constrained by funding. Recognizing this problem, the OFES of the DOE has proposed a plan for FY2004 which includes an increase in the national Alcator budget of about 20 percent. The MIT portion of the national budget would, under this plan, increase from the current $16 million (FY2003) to about $20 million in FY2004. The additional funds would be used to increase the research operating time to 21 weeks, to fund upgrades to RF current drive and diagnostic systems, and to increase the scientific and technical staff.
Highlights of recent research achievements include the following.
- Upgrades to our high resolution x-ray spectroscopy diagnostics have allowed us to make detailed measurements of the radial profiles of plasma rotation. These have revealed important information on the dynamics of momentum transport in low and high confinement regimes, and differences among discharges with different combinations of on-axis and off-axis RF heating. Experiments on this topic from most other tokamaks are done using strong momentum input from high power neutral beams. C-Mod has no such externally applied momentum sources, and the plasma rotation is caused by intrinsic transport processes, which are of fundamental interest to understand.
- High power radio waves in the ion cyclotron range of frequencies (near 80 MHz) have been used for heating, current drive and flow drive investigations during this year's experimental campaigns. Routine operation with more than 4 MW coupled to the plasma for long pulses, through 3 antenna structures, was enabled by a number of engineering modifications and upgrades that were implemented this year. Most importantly, the first experiments utilizing our 4-strap advanced antenna with phasing appropriate for flow and current drive were very successful, and should prove to be very valuable for the physics program in the coming years.
- Results from newly installed and upgraded visible imaging diagnostics, and comparisons with other, more mature measurements, have revealed important details of the dynamics of turbulent fluctuations near the edge of the plasma. These include the bursty nature of the turbulent structures, and their time and space correlation properties. The measurements are being compared to the results of detailed numerical simulations. These fluctuations are responsible for both energy and particle transport near the boundary of the confined plasma, which in turn can affect the overall confinement properties of the tokamak.
 Racetrack-shaped correction coils at the periphery of the Alcator C-Mod experiment. |
- The effects of nonaxisymmetric magnetic fields on the plasma is a topic which received considerable attention this year on Alcator C-Mod. Such fields can occur intrinsically, as a result of small (mm-scale) magnet misalignments, and can negatively affect the confinement of thermal and high-energy nonthermal (such as are produced by RF heating) plasma components. In extreme cases, they can be amplified by perturbations in the plasma, and sometimes lead to complete and sudden loss of the plasma. In order to study these effects in detail, seven new low-field magnets ("a-coils") were added to the facility, so that known asymmetric fields could be produced and studied. Initial studies have already revealed a number of important findings: typical intrinsic error fields are in the range of 3x10-4 tesla (3 gauss), which is just large enough to perturb the plasma under some operational conditions. The a-coils have been used to cancel the most important spatial component of this intrinsic field, as well as to map out the magnitude of error fields which can cause plasma effects. Comparisons with similar measurements on other, larger tokamaks, are revealing scalings for these phenomena which could have significant implications for the design of next step devices such as ITER.
The process leading to renewal of the Alcator 5 year research grant is essentially complete. An on-site peer review of the formal proposal was held during a two day meeting in May, and the reviews have been submitted to DOE. According to the written feedback we have received from DOE, the outcome of this process has been extremely positive. The new 5 year grant period is scheduled to begin in November, 2003.
Physics Reseach Division
The Physics Research Division, headed by Professor Miklos Porkolab, seeks to improve our theoretical and experimental understanding of plasma physics and fusion science. The division develops basic plasma physics experiments, new confinement concepts, novel inertial fusion diagnostics, and space plasma physics experiments, and is the home of a strong basic and applied plasma theory and computations program.
Fusion Theory and Computations
The theory effort, led by Dr. Peter Catto, supports the Alcator C-Mod and other tokamak experiments world-wide, the Levitated Dipole Experiment (LDX) scheduled to begin operation this year at the PSFC, and the Versatile Toroidal Facility (VTF). The following important contributions have been made by the group during the past year.
Tokamak Confinement and Transport
Further progress has been made by Drs. Darin Ernst and Paul Bonoli in understanding the physics of internal transport barriers that can be triggered in Alcator C-Mod by applying off-axis ion cyclotron heating power. They have identified mechanisms for both the formation and control of the internal barrier. Simulation of C-Mod shots early in time, when the temperature profile is peaked and the density profile is relatively flat, show a turbulent inward pinch. As the density profile peaks, this inflow reverses to become an outflow as density gradient driven turbulence replaces the ion temperature gradient drive. The turbulent outflow ultimately balances the standard inward collisional pinch leading to a steady state peaked density profile inside the barrier. The turbulent particle diffusivity from nonlinear simulations is temperature sensitive, allowing control of density peaking, and closely matches the value inferred from measurements.
Dr. Catto's tokamak edge studies focus on the impact of neutral penetration into the steep plasma density and temperature gradient region just inside the separatrix. The effect of the neutrals is evaluated by allowing poloidal variation of the neutral fueling. The localization of the neutrals is shown to result in a strongly sheared toroidal ion velocity and radial electric field which may locally reduce turbulent edge transport. Recent measurements on the MAST tokamak in England are in agreement with these predictions. In a separate study, Dr. Andrei Simakov and Dr. Catto have formulated a reduced description of turbulent transport for collisional tokamak plasmas which retains the key features of the full short mean free path description that they have carefully re-formulated and solved.
Magnetohydrodynamics and Extended Magnetohydrodynamics
Dr. Jesus Ramos has carried out the long standing task of deriving the correct dynamic evolution equations for the fluxes of thermal energy along the magnetic field in strongly magnetized, collisionless plasmas. This opens the possibility of formulating improved systems of fluid equations for collisionless plasmas. Dr. Ramos and visitors have also completed a collisional plasma study of pressure-driven Magnetohydrodynamics (MHD) instabilities that includes within a unified framework resistive and viscous dissipation, two-fluid diamagnetic effects, and sound wave propagation. This class of instabilities may be relevant to the quasi-coherent mode observed at the plasma edge in a particularly favorable operating regime of C-Mod.
In addition, Professor Jeff Freidberg and his student Antonio Bruno have developed a self-consistent transport model for ohmically heated reversed field pinches that predicts the magnitude and radial dependence of the anomalous cross field thermal diffusivity as well as the scaling relations for the energy confinement time and confined plasma pressure. The ohmic heating source permits a finite pressure gradient to be sustained that is adjusted until the entire profile is marginally stable to resistive MHD modes.
Heating, Current Drive, Advanced Tokamaks, and Nonlinear Dynamics
Principal research scientist Dr. Paul Bonoli's funding through the OFES's Scientific Discovery Through Advanced Computing Initiative ("Sci-Dac") has allowed him and Dr. John Wright to implement state of the art simulation models for current drive, heating, and mode conversion in the ion cyclotron and lower hybrid (LH) range of frequencies. These codes are used extensively by the C-Mod group to analyze heating and mode conversion experiments as well as assess planned LH current profile control experiments. Their full-wave electromagnetic field solver has been successfully used to resolve mode-converted ion Bernstein waves and electromagnetic ion cyclotron waves that are consistent with Alcator C-Mod observations.
A key element of the advanced tokamak program on Alcator C-Mod is noninductive current driven lower hybrid (LH) waves for current profile control experiments. We have an ongoing integrated scenario modeling effort to develop combined models for LH current drive, predictive transport analysis, ion cyclotron radio frequency (ICRF) heating, and ideal MHD stability. During the past year Dr. Bonoli and graduate student John Liptac have used the transport analysis code TRANSP in a predictive mode combined with the LH simulation package LSC to carry out exhaustive studies of proposed AT scenarios for Alcator C-Mod.
Recent experiments in tokamaks have demonstrated current profile control and stabilization of neoclassical tearing modes by localized electron cyclotron current drive. These experiments use the Fisch-Boozer mechanism for driving current by creating asymmetric resistivity. Recently, graduate student Joan Decker, Professor Abe Bers, and Dr. Abhay Ram have shown that Ohkawa current drive by electron cyclotron waves is a good candidate for off-axis current generation where the Fisch-Boozer mechanism is limited by trapped electrons. The Ohkawa current, generated by inducing asymmetric trapping of electrons, could be useful not only in conventional tokamaks but also, using electron Bernstein waves, in spherical tori.
LDX Stability, Heating and Confinement.
Theory research led by Dr. Jay Kesner in support of the Levitated Dipole Experiment (LDX) has found that dipole magnetic field equilibria are remarkably stable at arbitrary plasma pressure provided the pressure gradient remains below the ideal interchange limit. The formation of large scale convective cells leading to nonlocal transport is expected if the interchange limit is exceeded. Kinetic treatments able to retain diamagnetic and magnetic drift effects find that other closed magnetic field modes are excited which, unlike MHD modes, do not keep the entropy constant. Although they restrict the stable operating regime for LDX, a large operating space remains stable. When parallel and perpendicular resistivity is retained, weak resistive modes arise that may be observable in LDX. Electron cyclotron heating further complicates the stability picture and an investigation is under way.
Experimental Research
The Levitated Dipole Experiment
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. LDX is a joint collaborative project with Columbia University that is located in building NW21 at MIT. The principal investigators of this project are Dr. Jay Kesner of MIT and Professor Michael Mauel of Columbia University. The LDX facility has been designed by the engineering division of the Plasma Science Fusion Center (PSFC) under the leadership of Dr. Joseph Minervini.
 Vacuum vessel of the Levitated Dipole Experiment. |
The project has been funded as a 6-year grant at an approximate annual budget of $1.4 million (shared between MIT and Columbia University). A proposed 3-year grant to continue into the experimental operation phase of LDX beginning in FY2004 has been submitted to the DOE. The construction and assembly of the project is nearly complete and will be completed during the 6-year period. When completed, LDX will be the only superconducting magnetic confinement experiment in the US fusion research program. The vacuum chamber is in place in the Tara cell of NW21. The completed (high temperature superconductor) levitation coil is undergoing final tests at MIT and the NbTi charging coil has been completed in Russia (awaiting shipping from St. Petersburg, Russia) and is expected to arrive at MIT in August 2003. The high performance Nb3Sn floating coil has been successfully tested and the cryostat is nearly completed. The first plasma results are expected in the fall of 2003.
Magnetic Reconnection Experiments on the Versatile Toroidal Facility
At high temperatures, plasmas are generally "frozen" to magnetic field lines. Many plasmas, however, can occasionally break free rapidly, in a process called "magnetic reconnection". Based on experiments on the Versatile Toroidal Facility (VTF) device, the group led by Professor M. Porkolab and Dr. J. Egedal (and previously Professor A. Fasoli, who recently left MIT for Europe) has gained significant new insight into the fundamental mechanisms that allow magnetic field lines to break and reconnect at rapid rates. The experiments show that kinetic effects related to particle orbits can cause the breakdown of the classical theories. A new theoretical model of reconnection, developed on the basis of the experimental findings in VTF, is now successfully being applied in the interpretation of recent satellite data obtained during reconnection in the Earth's magnetotail. Finally, a new proposal by Professor Porkolab and Dr. Jan Egedal that will accelerate the VTF experiment has been funded by NSF/DOE for the next three years at $170K per year. Also, Will Fox, a Physics graduate student working on VTF has won a DOE fellowship to continue his thesis research on VTF.
MIT-PSFC/JET Collaboration on Alfvén Wave Instabilities
This program conducts experiments at the Joint European Torus (JET), the world's largest tokamak, in England. In these experiments instabilities driven by high energy particles, such as neutral beam ions, RF driven energetic ions and ultimately, alpha particles, are studied. These studies lead to an improved understanding of plasma stability and transport that will be important in a burning plasma experiment where the fusion process generates a substantial alpha particle component. This effort was originally led by Professor Ambrogio Fasoli who recently left MIT for Europe, but continues to participate in this experiment as a visiting professor. Professor Fasoli will remain coleader of the research with Professor Porkolab.
Inertial Confinement Fusion Experiments
MIT continues a major collaborative effort in inertial-confinement fusion (ICF). The group led by Dr. Richard Petrasso collaborates with the University of Rochester, where the 30-kJ OMEGA laser provides the most important current test bed for ICF experiments with direct laser drive, and the Lawrence Livermore National Laboratory, where the huge National Ignition Facility (NIF) under construction will host the next generation of ICF experiments expected to achieve ignition (self-sustaining burn and net energy gain) with "indirect drive" (2-MJ laser irradiating high-Z material outside the fuel capsule, generating x rays which irradiate and compress the capsule). MIT has carried out pioneering and important work in the development and use of several types of diagnostic techniques for these experiments, including spectrometers for studying charged fusion products generated in imploding ICF capsules. Recent experiments included studies of how deviations from perfect symmetry in laser drive affects the quality of capsule implosions. The experiments provided, for the first time, a direct measurement of the relationship between the angular variation of drive asymmetries and the resultant angular variations in capsule compression, and also determined the growth rates of compression asymmetries. In addition, the experiments provided information about the degradation of fusion yield due to compression asymmetry and quantitative information about an aspect of implosion dynamics that will be critical in future experiments designed to achieve ignition. This is the creation of a hot spot in the capsule center by coalescence of an ingoing shock wave generated at the capsule surface by the onset of drive. In the experiments, it was possible to study how that coalescence varied when the shock itself was nonspherical due to drive asymmetry. Other recent experiments have involved the study of indirect-drive experiments at OMEGA using charged-particle spectrometry, in preparation for future work at the NIF. Other important recent work includes development of a proton temporal diagnostic (PTD) for measuring the time-history of fusion burn, and development of a magnetic recoil spectrometer (MRS) for direct and scattered primary neutrons at OMEGA and the NIF. During the last year, this work has resulted in the publication of four articles in Physical Review Letters and a number of articles in other refereed journals. In addition, the MIT group, which has six PhD students working on several of these projects continues to play the lead role in organizing and coordinating the Basic Science Users Group for the National Ignition Facility.
Novel Diagnostics for Magnetic Fusion Research.
Phase Contrast Imaging Diagnostic of Turbulence on DIII-D
Professor Porkolab and Dr. Chris Rost, PSFC research scientist, have proposed new upgrades to the DIII-D collaboration in Phase Contrast Imaging of short wavelength modes, including an upgrade of the C-Mod PCI experiment. This proposal was funded at $235K per year for three years and the upgrading of the systems is underway. Initial experiments will commence in the fall of 2003.
Collective Thomson Scattering off Ions in Textor and Asdex-U
For fusion energy research, millimeter-wave collective Thomson scattering (CTS) diagnostics for fast ion measurements are being developed in an international collaboration between MIT, Risø National Laboratory, Denmark, and two German laboratories. Dr. Paul Woskov of the Plasma Technology Division, heads the PSFC's efforts for this collaboration. Energetic ions (alpha particles) are by-products of fusion burn in a D-T plasma. It is essential that these ions remain confined and give up their energy to fusion reactions to sustain energy production. Consequently, the physics of high-energy ions produced by auxiliary heating and by fusion reactions must be understood and controlled in order to progress to a practical source of power. The CTS development will provide a needed diagnostic tool enabling this progress. Experiments will be carried out on the German TEXTOR and ASDEX-Upgrade tokamaks, which have unique high power gyrotron facilities for providing the high-power millimeter-waves needed for this research.
Ionospheric Plasma Research
 Linear array of antennas for IRIS radar system (electronics located in the trailer in the background). |
PSFC's Ionospheric Plasma Research Group (visiting professor Min-Chang Lee of Boston University and his students) has been conducting ionospheric plasma RF heating experiments in Alaska, using DOD's HF Active Aurora Research Program (HAARP) facility. These experiments are aimed at investigating ionospheric plasma turbulence and developing ELF/VLF communication schemes for high efficiency and good quality signals. Progress has been made to determine the spatial distribution of HF-modulated electrojet currents and sources of ELF/VLF emissions. PSFC's Ionospheric Radar Integrated System has been deployed for experiments at Millstone Hill, Massachusetts for remote sensing of space plasma turbulence. The new optical instrument, All Sky Imaging System (ASIS) will be soon used in experiments to study the spatial structures of plasma turbulence. ASIS together with IRIS will provide powerful diagnoses of RF heated plasmas in space and laboratory experiments. A proposal will be submitted to DOD to acquire a LIDAR (Light Detection And Ranging) which can provide information on the distance, drift velocity, and the density of the plasma species being investigated.
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. Substantial graduate student involvement is emphasized in all research programs within the division.
Gyrotrons are under development for: electron cyclotron heating (ECH) of present day and future plasmas, including the ITER plasma; for high frequency radar; and, for spectroscopy. These applications require gyrotron tubes operating at frequencies in the range 90-500 GHz at power levels of up to several megawatts. In 2003, the Gyrotron Group headed by Dr. Michael Shapiro, successfully operated a 1.5 MW, 110 GHz gyrotron for 3 microseconds. In operation at 96 kV and 40 A, power levels of over 1.4 MW and an efficiency of 36 percent were achieved. The research at MIT will be followed by a development program for a continuous wave gyrotron, which will be built and tested at an industrial vendor, Communications and Power Industries (Palo Alto, CA). In a research program on gyrotron amplifiers, funded as part of a US Department of Defense MURI (Multidisciplinary Research Program of the University Research Initiative) consortium for Innovative Vacuum Electronics, a novel 140 GHz gyrotron amplifier has been tested. Thirty kW peak power, which is a record power level at that frequency, has been demonstrated with a 29 dB linear gain and at a 2.3 GHz bandwidth. These results will be very useful to scientists at MIT's Lincoln Lab who are working on a high frequency amplifier for the Haystack antenna based radar.
Intensive research continues on 250–500 GHz gyrotrons for use in electron spin resonance and nuclear magnetic resonance studies. This research, funded by NIH, is a collaboration with Professor Robert Griffin of the Francis Bitter Magnet Lab. In 2003, we completed construction and obtained first results with a new 460 GHz gyrotron. Oscillation of the gyrotron in a series of modes at the fundamental frequency near 230 GHz was studied. Operation at the second harmonic near 460 GHz is the next goal.
PSFC research on high gradient accelerators is focused on high frequency linear accelerators for development of future TeV electron colliders. In 2003, the High Gradient Accelerator Group continued operation of the Haimson Research Corp. 17 GHz electron accelerator. This is the highest power accelerator on the MIT campus and the highest frequency stand-alone accelerator in the world. The diagnostic set up is under construction to measure the electron bunches from the 17 GHz accelerator. A test of a photonic bandgap accelerator cavity is also planned.
The Intense Beam Theoretical Group, led by Dr. Chiping Chen, has contributed to our understanding of coherent radiation generation and particle acceleration. Topics covered include coherent radiation generation in crossed field devices, control of halo formation in intense electron and ion beam transport, and the design of metallic photonic band gap structures for use in coherent radiation structures. An important recent achievement is the use of a Green's function based simulation code to determine an annular beam confinement limit for bunched electron beams in high-power microwave sources.
Technology and Engineering Division
The Technology and Engineering (T&E) Division, headed by Dr. Joseph Minervini, conducts research on conventional and superconducting magnets for fusion devices and other large-scale power and energy systems. The division's major emphasis continues to be on support of the US Fusion Program where the PSFC has the leadership responsibility for the Magnets Enabling Technology program. Funding for fusion technology remained flat this fiscal year, but there is a possibility of at least modest increases for magnet technology in FY2004 because the US has entered international negotiations to rejoin ITER. MIT continues it's lead role for representing US magnet technology to this project. The T&E Division has taken a lead national role in developing the costs for the magnet systems of ITER. These are the most expensive of all the tokamak systems and are likely to be part of any US contribution package. If the ITER project moves forward with US participation, substantial funding would be possible by FY2006 which is projected to be the first year of construction.
Last August, the division hosted at MIT the US-Japan Workshop on Superconducting Magnet Technology to discuss the test results from a recent series of major ITER model coil tests, including analysis and supporting R&D. More than 35 participants attended, including representatives from national laboratories and universities in Japan, Europe , Russia and the US.
Although ITER is the presently preferred US Burning Plasma Experiment (BPX), the division continues to provide engineering design support to the Princeton Plasma Physics Laboratory in the evaluation of the Fusion Ignition Research Experiment (FIRE). The division performs analysis and design of the magnet and cryogenic systems for FIRE. In the past year, efforts have been focused on advanced tokamak physics in FIRE. The coils have been requalified, and are undergoing optimization of their configurations for various operational modes. Engineering reports are being updated in preparation for the Physics Validation Review in September of 2003.
Another OFES funded project is the fabrication and testing of a cryostat for the superconducting focusing quadrupole magnets suitable for use in a heavy ion driven inertial fusion device. This IFE project is performed in collaboration with the Lawrence Berkeley National Laboratory and the Lawrence Livermore National Laboratory.
Division engineers have been completing the fabrication and assembly of the magnet systems for the Levitated Dipole Experiment (LDX). The Levitation Coil (L-Coil) was completed and successfully tested, demonstrating the first use of high temperature superconducting magnet technology in the US fusion program. Fabrication and testing of the larger scale Charging Coil (C-Coil) was completed by the D.V. Efremov Institute-Sintez at St. Petersburg, Russia. Delivery of the coil to MIT is imminent. Assembly of the entire LDX machine should be completed by the fall, followed by startup of physics operations.
The division has continued its previous activity in non-OFES funded work with the Muon-to-Electron-Conversion Experiment (MECO), which is part of the Rare Symmetry Violating Processes (RSVP) experiment. The experiment is being funded by the NSF with a currently planned construction start in FY06 and will be installed in the Alternating Gradient Synchrotron (AGS) facility at Brookhaven National Laboratory. The division completed a conceptual design on the 94-solenoid, superconducting magnet system in February, 2002. Since that time, division staff member Bradford Smith has been named the MECO Magnets subsystem manager, and he has been preparing a specification and statement of work for magnet final design, fabrication and installation to be executed under an industrial RFP.
The division contributed to the national high-energy physics team R&D effort for a muon collider, or neutrino factory based on a storage ring that requires intense beams of muons that are obtained from pion decay. Pion production from a proton beam interaction is maximized by use of a high Z material such as mercury. Brookhaven National Laboratory, Princeton University, and other collaborators are developing mercury jets as targets where the interaction zone with a proton beam is located in a magnetic field of up to 22 T. The R&D effort involves analytic simulation and experimental investigation of the mercury flow. Peter Titus led the MIT design and analysis of a cryogenically-cooled, pulsed copper coil that can produce 15T with sufficient bore volume for the experiment, and which can be located in one of the AGS experimental halls at Brookhaven National Laboratory. Bids for the magnet and its vessels are due mid July. It is planned that the magnet will be tested at MIT-PSFC prior to its service with an accelerator at BNL in late 2004/early 2005.
Work is being completed on a NASA-funded Phase-II STTR, in collaboration with the Advanced Magnet Laboratory, a Florida-based small business. The project is to develop a superconducting magnetic levitation coil as a demonstration of a "Maglifter" type of magnetic launch assist. Two coils and cryostats are being fabricated: a floating F-Coil, and a CL-coil for inductive charging and levitation of the CL-coil. The cryostat is being fabricated by International Cryogenics. Testing at MIT of CL-coil field and current performance and F-coil cool-down should be completed in September. The goal of a Phase III proposal will be to demonstrate the capability of the superconducting levitation system to lift 100 times its own weight.
A magnetic separation project supported by NIH is being carried out to develop a continuous, very sensitive magnetic separation method for biological cells, such as red and white blood cells, using a 12 T superconducting magnet. As part of this project, a device consisting of a high magnification microscope and a high-resolution digital CCD camera has been developed to observe magnetic separation processes and to measure the magnetic susceptibility of individual particles or biological cells.
The division had expected to begin prototype magnet design and development of proton radiography superconducting quadrupole focusing magnets for the Advanced Hydrodynamic Facility (AHF) being developed at the Los Alamos National Laboratory. Funding for this project, however, was cancelled in FY2003 and this program was ended.
The division continues to actively seek other, non-OFES sources of funding. Proposals are being prepared for two different medical applications of advanced superconducting magnet technology. One application is a high-field, superconducting synchrocyclotron for proton radiation therapy for cancer treatment. Another application being pursued is a tri-axial magnetic catheter steering system for gastroenterological use. NIH is the potential funding agency.
Plasma Technology Division
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 and hydrocarbon energy efficiency area; to develop new fusion diagnostics (see "(b.) Collective Thomson Scattering off Ions in Textor and Asdex-U" under the "Physics Research Division"); and, to develop new fusion reactor system concepts.
A growing research area in the division is plasma-assisted conversion of hydrocarbon fuels into hydrogen with Drs. Leslie Bromberg and Daniel Cohn as coprincipal investigators. Hydrogen has potential environmental advantages as a fuel additive that can greatly reduce pollution from vehicles and stationary electricity generation systems. It can also be used to increase the efficiency of conversion of hydrocarbon fuels into mechanical power or electrical power. Special plasma technology, referred to as plasmatron reformers can provide important advantages in promoting the generation of hydrogen from hydrocarbon fuels. The division's activities in this area contribute to the goals of:
- Development of near term spinoff applications of fusion energies sciences research
- Expanded collaboration between the PSFC and other academic departments and other laboratories
- Increasing industrial support for PSFC research
 Microplasmatron fuel converter (foreground) and conventional carburetor (background). |
ArvinMeritor, a major manufacturer of automotive components is funding research into the application of plasmatron reformer devices to vehicles with conventional internal combustion engines. The plasmatron reformer converts a fraction of the gasoline to hydrogen rich gas that is then combusted along with the gasoline in a slightly modified engine. The hydrogen rich gas makes for an ultra-lean fuel mixture that burns cleaner and is more efficient. In particular, lean burn operation of hydrogen rich gas in conjunction with turbocharging can lead to increases in net engine system efficiency of 30 percent as well as large reductions in NOx, a major air pollutant.
The relatively low incremental cost of the plasmaton should lead to a relatively short payback time. The short payback time could potentially make possible widespread implementation on cars and light duty vehicles with the potential for gasoline savings in the US of 20 billion gallons a year. The project is a collaborative effort with Professor John Heywood of the Mechanical Engineering Department and the Sloan Automotive Laboratory.
A new program involving an expansion in this collaborative effort has been proposed to DOE. The new effort would involve a broad study of new clean, high efficiency engine concepts referred to as Hydrogen Enhanced Gasoline Engines. Such engines could serve as a bridge to the long-term national goal of vehicles using stored hydrogen while also providing near term fuel savings as described above. The need for vehicles with significant near term fuel savings has recently been increased by legislation in California calling for reduced greenhouse gas emissions from vehicles.
Another project, supported by DOE, investigates the use of plasmatron reformer generated hydrogen as a means to significantly improve catalytic elimination of NOx in diesel engine exhaust. In parallel, ArvinMeritor is working to develop this technology into a commercial product. Plasmatron enhanced catalytic NOx reduction could play an important role in substantially reducing diesel vehicle emissions. The DOE sponsored research also studies the use of plasmatron reformer technology to convert bio-fuels, including ethanol and bio-oils, into hydrogen-rich gas for vehicular applications.
In addition, the Plasma Technology Division is investigating the use of plasma-based devices for improving the production of hydrogen for stationary fuel cells that use natural gas. This work is sponsored by Chevron Texaco. The division is also researching and developing advanced diagnostic and monitoring systems for fusion energy research, environmental monitoring, and nuclear waste remediation.
In the environmental monitoring area, the Plasma Technology Division is developing millimeter-wave pyrometry, reflectometry, and viscometry for online monitoring of nuclear waste vitrification processes. The objectives of this technology development effort are to speed up and reduce costs of the national effort to clean up nuclear waste sites. The new online monitoring technology could maximize the waste content in the glass product, thereby reducing cost and could also increase reliability. This will result in large cost savings. The work to date has received important awards and recognition. An R&D 100 Award was earned in 2001 for the viscometry development as one of the most significant new technologies in that year. Also, a presentation given at the 2001 American Ceramics Society Meeting earned a best paper award within the Nuclear and Environmental Technology Division. This work was also highlighted as an Environmental Management Science Program (EMSP) success story at the American Nuclear Society 2002 Spectrum meeting.
Educational Outreach Programs
The Plasma Science and Fusion Center's educational outreach program is planned and organized under the direction of Paul Rivenberg, communications and outreach administrator of the PSFC. The program focuses on heightening the interest of K–12 students in scientific and technical subjects by bringing them together with scientists, engineers and graduate students in real laboratory and experimental environments. This kind of interaction often encourages young people to consider science and engineering careers. Tours of our facilities are also available for the general public. Annual visitors include Minority Introduction to Engineering, Science and Entrepreneurship Program (MITE2S), Keys to Empowering Youth (KEYS), and the National Youth Leadership Forum. Special "Outreach Days" are held twice a year, encouraging high school and middle school students from around Massachusetts to visit the PSFC for hands-on demonstrations and tours. Key to the success of our tour programs is the involvement of PSFC graduate students who volunteer to assist. The experience helps them understand how to communicate a complicated science to those who do not have an advanced science background.
The Mr. Magnet Program, headed by Paul Thomas, has completed twelve years of bringing lively demonstrations on magnetism into local elementary and middle schools. This year Mr. Magnet presented the program to over 30,000 students at over 75 schools and other events, reaching students from kindergarten through college freshmen. He makes a special effort to encourage girls to consider science-related careers. In May, 2003 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 eclectic collection of magnetic and plasma phenomena. In addition to his program on magnets, Paul Thomas is offering a program about plasma to high schools and museums. This is an interactive demonstration, encouraging participants to investigate plasma properties with audiovisual, electromagnetic, and spectroscopic techniques. He is currently researching local science museums that might want to create an exhibit on plasma, for which he would provide a hands-on interactive plasma generation device. He has also developed a workshop for middle schools on how to build an electromagnet. Mr. Thomas also collaborates regularly with the MIT Museum's Sunday science program.
The PSFC continues to collaborate with other national laboratories on educational events. 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. Mr. Rivenberg, Mr. Thomas, and Ms. Valerie Censabella, Alcator administrator, aided organizers of the 2002 education events in Orlando, Florida, which attracted about 77 teachers, and over 1600 students. Here the PSFC featured Paul Thomas and his most recent plasma education device at the education poster session. Mr. Rivenberg will be in charge of organizing the education events for the 2004 APS-DPP Meeting in Savannah, Georgia, and has already begun preliminary work with teacher contacts in that region.
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. 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. Mr. Rivenberg also heads a subcommittee that created and maintains a web site to help teachers bring the topic of plasma into their classrooms. Paul also works with the Technical Materials subcommittee, where he oversees content and layout of two-page information sheets that introduce the layman to different areas of plasma science. Most recently, he is helping to explore creating a plasma education web site that would be part of the Institute of Electrical and Electronics Engineers (IEEE) Virtual Museum. He is assisted by Mary Pat McNally, who provides support for all graphics projects.
Appointments and Promotions
During the past year, there have been a number of appointments and promotions in Plasma Science and Fusion Center program areas:
- In the Alcator Division, Dr. Nils Basse was appointed postdoctoral associate. In the Physics Research Division, Dr. Christopher Boswell was appointed postdoctorial associate. In the Waves and Beams Division, Drs. Mark Hess, Amit Kesar, and Jagadishwar Sirigiri were appointed postdoctoral associates.
- In the Alcator Division, Dr. Yijun Lin was promoted to research scientist, Charles Schwartz was appointed RF engineer, and Dexter Beals was appointed engineer.
Graduate Degrees
During the past year, the following departments granted students degrees with theses in plasma fusion and related areas:
- In Nuclear Engineering, Mark Adams, Christopher Boswell, Sanjay Gangadhara, Davis Lee, and Khashayar Shadman received PhD, and Erik Tejero received an MS.
- In Physics, Jon Nazemi received an MS degree.
- In Electrical Engineering and Computer Science, Ryan Riddolls and Jagadishwar Sirigiri received PhDs.
More information about the Plasma Science and Fusion Center can be found on the web at http://www.psfc.mit.edu/.