MIT Reports to the President
FRANCIS BITTER MAGNET LABORATORY
The Francis Bitter Magnet Laboratory (FBML) has continued to make notable advances
in several areas of science and engineering involving high magnetic fields.
The research program in Magnetic Resonance (nuclear magnetic resonance (NMR),
and electron paramagnetic resonance (EPR)) has continued to grow and remains
the largest effort at the FBML. The program is funded primarily by the NIH and
DOE, and involves ~20 NMR and EPR magnets and spectrometers.
A few of this years highlights include the following.
Professor Robert G. Griffin, together with Professor Gerhard Wagner of Harvard
University, continue to operate The MIT/Harvard Center for Magnetic Resonance,
a collaborative research effort between MIT and Harvard Medical School. The
Center is supported by a NIH Research Resource grant that was renewed for five
Professor Harald Schwalbe joined the Department of Chemistry in October, 1999.
His offices and laboratory space are presently located at the FBML. Professor
Schwalbes area of research is focussed on solution NMR studies of protein
folding and structures of ribonucleic acids.
Professor Cory and his colleagues continue to make rapid advances in the theory,
practice and implementation of quantum information processing. In collaboration
with Bruker Instruments, Inc., they have helped to develop and taken delivery
of the first special-purpose commercial NMR designed for quantum information
processing. They are now constructing a second-generation quantum processor
that is designed to reach more than 10 qubits.
Dr. Yukikazu Iwasa received funding from NIH to construct a very high field,
wide bore 700 MHz NMR system. The system is essentially complete and has successfully
passed most test and we anticipate delivery in a few weeks. A unique feature
of the magnet is a ±500 Gauss sweep coil essential for dynamic nuclear polarization
Dr. Jagadeesh Moodera has continued to strengthen his research efforts in condensed
matter physics through collaboration with various universities and industries,
as well as the ONR and NSF. In addition, he has continued his mentoring of graduate
students, undergraduate and high school students by providing research opportunities
within his lab. Dr. Moodera received the 2000 TDK Research Award for his pioneering
studies in spin tunneling.
Professor David G. Corys research activities include the following:
- Quantum Information Processing (QIP). Professor Cory continues to explore
NMR approaches to quantum information processing through a set of collaborations
with Dr. T. Havel (HMS), Professor Seth Lloyd (Mechanical Engineering), Dr.
Raymond Laflamme (LANL), Dr. E. Knill (LANL) and Dr. J. Yepez (AFRL). Much
of our recent efforts have been directed to making liquid-state NMR implementations
of quantum information processing robust at the level of 5 to 7 qubits. They
have also articulated two new schemes for extending the success of NMR approaches
to QIP to larger systems and have started to build a solid-state device capable
of coherently controlling 10 ñ 30 qubits, which will have the unique
feature of a resettable qubit. This is essential for exploring quantum error
- NMR of heterogeneous semi-solids. In collaboration with Dr. S. Singer, and
Dr. Pabitra Sen of Schlumberger Doll Research Laboratory, Professor Cory has
continued to explore the structure and fluid dynamics of complex media. This
is facilitated by a series of recently developed methods that permit the separation
of the pore structure factor from the incoherent fluid motion. They have shown
that the NMR signal (after suitable averaging and manipulation) provides a
fingerprint of the sample geometry and that much of the inverse problem can
be solved. Applications are expected in both biology and in granular or porous
- NMR imaging of fluid transport through granular media. In collaborations
with Professor Culligan (Civil and Environmental Engineering) and Professor
Czerwinski (Nuclear Engineering), the transport of lanthanides and the displacement
of contaminants in model sands, soils and resins are being studied by NMR.
For resorcinol resins (used to trap metals) the NMR results provide a clean
and unambiguous measure of bound, plasticizer and free water ñ including
their exchange properties.
Professor Robert G. Griffins research acitivities included the following:
- High Frequency Electron Paramagnetic Resonance (EPR). About a year ago the
capabilities of the 140 GHz EPR spectrometer were dramatically extended by
the incorporation of a four-phase microwave pulse-forming network and amplifier
with 30 mW of output power. Professor Griffin has just received funding for
a further upgrade to ~110 mW. The greater microwave power and phase switching
capability allows us to develop and perform sophisticated pulsed EPR techniques.
In particular, his group is working on developing new pulsed methods for spectral
filtering, electron/nuclear cross polarization and multiquantum EPR experiments
for measuring long-range distances (10-30 Å) in spin labeled proteins
and peptides. In addition, the 140 GHz pulsed Electron-Nuclear Double Resonance
(ENDOR) capability has already been used to examine a number of systems. For
example, the increased sensitivity, resolution, and orientation selection
available in the ENDOR experiment at this high frequency/field has enabled
us to determine in detail the electronic structure of the tyrosyl radical
of ribonucleotide reductase. (RNR) ENDOR studies of the RNR inhibitor complexes.
- Structural Studies of Alzheimers Disease Amyloid. Amyloidoses are
a group of peptide or protein misfolding disorders characterized by the accumulation
of insoluble fibrillar protein material in extracellular spaces. Sixteen different
peptides are known to form amyloid-like aggregates. The aggregation of these
peptides is involved in several diseases. ß-amyloid (Aß) is involved
in Alzheimer's disease, the conversion of the prion protein PrPc to PrPsc
leads to the transmissible spongiform encephalopathie, and the synuclein protein
is responsible for Parkinson's disease.
- During the last two years, Professor Griffins lab has worked on methods
to obtain large amounts of fibrillar peptide material. Fibril preparation
is crucial for obtaining narrow lines, maximizing spectral resolution, and
optimizing signal intensities. Fibril formation is also important for the
biological relevance of the structural model. Furthermore, we have obtained
13C/15N labeled Ab 1-40 and prepared fibrils of
this material. High-resolution AFM (Atome Force Microscopy) images indicate
that this fragment forms regular fibrils as well and our first 13C
/15N MAS spectra reveal resolved a few resonances. During the coming
year, we are planing serious structural studies of the Ab peptide.
A web site describing some of Professor Griffins research can be found
In addition, Professor Griffins group has underway studies of smaller
fibrillar peptides in collaboration with Professor Chris Dobson of Cambridge
- Dynamic Nuclear Polarization. During the past year they have operated the
250 GHz gyrotron on a routine basis and have initiated high frequency DNP
experiments with the device. The DNP/NMR spectrometer consist of 125 mm bore
375 MHz NMR magnet and a new spectrometer console is being assembled for these
experiments. The initial results indicate that we will achieve substantial
signal enhancements at this frequency. At present these represent the highest
frequency DNP experiments ever performed, and more importantly suggest that
even higher frequency operation will be successful. Thus, in collaboration
with the PSFC they are now in the process of designing and constructing a
460 GHz gyrotron that will be used in conjunction with the 700/89 widebore
magnet mentioned above.
- Dipolar Recoupling. Over the last decade they have been heavily involved
in the development of techniques to measure distances and torsion angles in
solids. The ultimate goal is to be able to determine the structure of membrane
proteins, amyloid fibrils, etc with solid state NMR. This past year we have
succeeded in developing methods for performing these experiments in uniformly
13C /15N labeled molecules and we have utilized them
to determine the structure of a small peptide. They anticipate that with increased
signal to noise available form DNP experiments that these methods will be
applicable to a large number of systems not accessible to solution NMR and
X-ray crystallographic investigations.
- Center for Magnetic Resonance. The Center for Magnetic Resonance has completed
its 24th year of operation as a facility open to scientists needing
access to high field NMR equipment. During this year, 69 projects were worked
on by 126 investigators, from departments within MIT including Chemistry,
Physics and Nuclear Engineering, as well as users and collaborators from institutions
outside of MIT such as Harvard University, Brandeis University and Brigham
& Womens Hospital. Work resulted in 52 publications in print or
in press. Highlights of work conducted at the center include advances in high
frequency dynamic nuclear polarization of proteins (DNP), time resolved studies
of protein folding, structures of large proteins, and high frequency EPR and
ENDOR. A competing proposal was submitted to NIH for review during the summer
of 1998 and is now funded for an additional five-year period.
Dr. Yukikazu Iwasas research activities include the following:
- Dr. Iwasas group has continued research on the key operational issue
of protection for high temperature superconducting (HTS) magnets operating
in the temperature range 10-60 K. In addition to this basic protection study,
they have investigated practical aspects of cryocooler-cooled operation. They
have studied small coils wound from silver-sheathed BSCCO-2223 tapes in the
temperature range 20--60 K. they have developed a numerical NZP model for
a three-dimensional, dry-wound, BSSCO-2223 superconducting magnet. The test
magnet operates under quasi-adiabatic conditions at 20~K and above, in zero
background field. The NZP model is based on the two-dimensional transient
heat diffusion equation. Agreement between voltage traces obtained in the
test magnet during heater-induced quenching events and those computed by the
numerical NZP model is reasonable. The model is also used to simulate quenching
in magnets similar to the test magnet.
- A new 2-year DOE-funded joint FBML-FSU/NHMFL project has started on 06/01/2000
to study stability and quench protection of YBCO wires and coils. Of particular
interest to the project is the study of beneficial effects of solid nitrogen
impregnated in the winding of a high-temperature superconducting coil. Solid
nitrogen in the temperature range below ~60K has a heat capacity much greater
than that of silver. Thus, even a small amount of solid nitrogen present within
the coil winding is expected to enhance the overall heat capacity of the winding,
making the coil more stable against transient heating such as that can be
caused by overcurrent pulses in electric power devices.
- Also started on 06/01/2000 is a new 2-year NIH-funded project on development
of a flux pump for use in a high-field superconducting NMR magnet containing
a high-temperature superconducting insert coil. Because of low indices, HTS
insert coils, even with superconducting splices, cannot be operated perfectly
in persistent mode; their currents will decay slowly albeit at a very small
rate. An HTS insert coil coupled to a flux pump can receive precisely metered
quantities of energy and operate effectively in persistent mode.
- His work on developing a "permanent" HTS magnet system is nearly
complete. The system combines the simplicity and ease of operation of a ferromagnetic
permanent magnet with the strength, capability and versatility in field generation
of an electromagnet. Once energized and producing a desired field, the system,
without being coupled to a cooling source, can maintain that field for a long
period. This HTS magnet is particularly suitable for an on-board or portable
unit requiring a constant field and where "permanence" means a duration
of hours, days, weeks, months, or even years. The systems other features
are "recooling" and "recharging" capabilities designed
to have the system re-cooled while maintaining its constant field to make
the field literally permanent, and recharged if its upper operating temperature
is exceeded and the field decays.
- An application has been filed to the U.S. Patent and Trademark Office for
invention of a new high-temperature superconducting (HTS) current lead. The
new HTS lead requires HTS materials that are substantially less than those
required by the conventional HTS current leads available on the market. The
core of the invention is that, in the new HTS current lead, a warm part of
the HTS lead is operated in the so-called "current-sharing" (partially
resistive) mode rather than completely in the superconducting state as in
the conventional HTS current lead.
Dr. Jagadeesh S. Mooderas research activities include the following:
- In condensed matter physics, in particular magnetism, his research continues
to make significant contributions to both fundamental science and industrial
application. His basic investigation emphasizes interfacial exchange interaction
and spin transport in thin film structures. Using his molecular beam epitaxy
(MBE) system, his research seeks to contribute to the understanding of the
spin properties of conventional materials and to unraveling the spin properties
of certain novel magnetic compounds that have a high potential for technological
application. His research in these materials has already shown the possibility
of a four-level memory/logic element. Several companies, including IBM, HP,
Motorola, TDK and Fujitsu, are developing this structure for application in
digital storage. In this context, his group is continuing national and international
collaborative research efforts with scientists and faculty from national laboratories,
US universities, the University of Paris at Orsay, the University of Eindhoven,
Tohoku University, the Tata Institute of Fundamental Research and the Ukrainian
Academy of Sciences. Exchange of scientists and graduate students is a part
of this program.
- In the area of semiconductors, our continued collaboration with Hewlett-Packard
Company has been valuable in searching for far future material for atomically
resolved storage ( > Terabytes/in2 ). He are exploring the materials
with the appropriate properties and giving HP the fundamental information
necessary for their program. In this direction we have been successful in
identifying a possible candidate material from among thousands of compounds.
There is ongoing collaboration with other companies such as NVE Inc., TDK
(Japan) in the field of magnetism.
- Three postdoctoral scholars, one graduate, four undergraduate and four high
school students have taken part in Dr. Mooderas research. One graduate
student (from DMSE) obtained his doctoral degree. The high school students
won several science competitions, including a semifinalist in Intel-Westinghouse
Science Competition, as well as other regional top awards. Notably, one high
school student who participated in the RSI program at MIT under Dr. Mooderas
supervision won the top award in Singapore National Science competition. Research
resulted in nine publications and over ten invited talks at various national
and international conferences, universities and laboratories. Dr. Moodera
spent some time at Eindhoven Technical University as a visiting professor
and was one of five US researchers invited to give a presentation and participate
in a NSF panel discussion regarding the next ten years of research initiative.
In addition, he was invited to write a feature article for Physics Today and
received TDK Research Award once again in 2000 for his research in spin tunneling.
Dr. Harald Schwalbes research includes the following:
- His research is focussed on the studies of structural and kinetic aspects
of protein folding. He uses high resolution NMR spectroscopy as our primary
tool. The random coil state of a protein consists of an ensemble of conformers.
We have developed a model to predict the conformational averaging around the
angles f, y, and c1 in the random coil state and could test this model from
NMR measurements of chemical shifts, coupling constants and cross-correlated
relaxation rates. In order to link the conformational analysis with the kinetics
of folding, we are carrying out time-resolved NMR studies to gain insight
into the structures of folding intermediates. This has been achieved by coupling
the folding of proteins to the rapid release of ions from photo labile precursor
molecules. The folding kinetics of single atoms could be determined. The accessibility
of aromatic residues was further tested using Photo-CIDNP experiments. Single
scan experiments could be performed that show the reorientation of the hydrophobic
core of the protein during folding.
- A second focus is the characterization of structure and dynamics of RNA.
His group was able to develop new NMR methods to determine all free torsion
angles in RNA oligonucleotides including the backbone angles a and z which
were considered inaccessible in the literature by exploiting cross-correlated
relaxation in high resolution NMR. New research is now determining the geometry
and energetics of Watson-Crick base pairs in solution. In the light of our
new findings, Watson-Crick base pairs have to be described by a three state
model, in which an intermediate is populated for 1%. In this intermediate,
the nucleobases remain stacked but the hydrogen bonding interactions are weakened.
Our new data allows the dissection of the energy contribution of hydrogen
bonds and stacking to base pair stability.
During the past year, FBML resources were consolidated into one building. We
now boast an upgraded space for 2 750 MHz NMR magnets, as well as space for
the wide bore 750 MHz magnet to be built under Dr. Yukikazu Iwasa.
Newly renovated facilities have recently been provided for Professor Corys
research group, including a wet lab and a computer lab.
Professors Keith Nelson and Andrei Tokmakoff of the Department of Chemistry
have left the temporary lab space on the first floor used during completion
of their permanent laser lab facility in the Chemistry Department.
Extensive renovation has been complete on the second floor to provide office
space for Professor Jacquelyn Yanch, Professor David Cory and their students.
EDUCATION AND PERSONNEL
The Laboratory contributes to undergraduate education by participation in the
Undergraduate Research Opportunities Program (UROP) a program that encourages
and supports research-based intellectual collaborations of MIT undergraduates
with Institute faculty and research staff. In addition, the laboratory has 20
full-time graduate and 8 postdoctoral students performing research.
Third magnet cell for a wide bore 700 MHz magnet is under renovation and requires
During the past year 900 MHz instruments have been completed, and we have been
told that NIH will issue a call for proposals to purchase these instruments
early in 2001. We plan to submit such a proposal for a complete system which
will be part of the MIT-Harvard CMR. In connection with this proposal will be
requesting that NW15 be renovated to accommodate two 900/1000 MHz NMR magnets.
In the longer term we also plan to complete construction of the second floor
magnet hall, and instruments currently housed on the fourth and fifth floors
will be relocated in order to create a comprehensive "Center for Magnetic
Resonance." An alternative plan would be as Professor Schwalbes research
group grows, the space could house his instrumentation.
Robert G. Griffin
MIT Reports to the President