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  • MIT NSE: Nuclear Fusion & Plasma Physics
    in Extreme Environments CANES CASL Labs Centers Facilities Resources NSE Spotlights Future of the Nuclear Fuel Cycle Future of Nuclear Power The Extreme Materials Environment of a Magnetic Fusion Reactor Eventual fusion reactors will make net energy due to the fusing of magnetically confined hydrogen isotopes of deuterium and tritium at about 100 million degrees C This extreme temperature means the fuel is in the plasma state like the interior of stars and physical materials must be kept far away One of the great scientific challenges of fusion is understanding how the fusion energy is eventually exhausted through the surrounding materials This is being studied at MIT with a small scale fusion reactor Alcator C Mod It heats the plasma by using radio waves and the plasma is contained in a donut shaped magnetic field that is about 100 000 times the strength of Earth s magnetic field Tungsten is one of the best candidate materials for fusion reactors it carries away heat efficiently and it has the highest melting point 3400 C Over the span of a year Alcatorscientists tested a row of tungsten tiles embedded in the section of the wall called the divertor the region where magnetic field lines are diverted for purposes of heat exhaust The good news was that most of the tungsten surfaces performed admirably However at one location a mechanical problem occurred that made the tile misalign to the grazing magnetic field As a result the tungsten surfaces received the full brunt of the plasma power along the magnetic field line about 1 billion watts per square meter Over a year s campaign the tungsten was exposed one thousand times The material damage and deformation is very complicated because it occurs at extremes of power flux electric current and magnetic field Close examination

    Original URL path: http://web.mit.edu/nse/research/tungsten_slideshow.html (2016-02-01)
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  • MIT NSE: News: 2010
    Committee is being established in accordance with the Federal Advisory Committee Act FACA DOE also expects to organize various subcommittees under ERAC More about ERAC ERAC members John Holdren sees opportunities in energy challenges The two toughest challenges the nation faces in terms of energy according to presidential science adviser John Holdren 65 SM 66 are meeting our transportation needs with less oil and meeting economic aspirations while producing less climate altering carbon dioxide emissions But the good news he told an MIT audience on Monday Oct 25 is that meeting those challenges really can promote significant job creation and business growth Holdren delivering the David J Rose Lecture in Nuclear Technology noted that as of 2008 82 percent of the world s energy needs were being met through the use of fossil fuels a degree of dependence he called shocking And the percentage of fossil fuel dependence is even higher in the United States and China he said read MIT News article watch lecture download slides from lecture about Rose Lectureship in Nuclear Technology NSE graduate student wins NuMat award NSE graduate student Yue Fan won the Young Scientist Best Presentation Award at the Nuclear Materials Conference NuMat for his paper entitled Microstructural Evolution of Vacancy Clusters in bcc Fe Kinetics at the Experimental Time Scales The award for originality of the research and quality of the presentation was presented at the inaugural NuMat held on 4 7 October 2010 in Karlsruhe Germany The paper was co authored with Akihiro Kushima and Profs Sidney Yip and Bilge Yildiz of the Department of Nuclear Science and Engineering It discusses a new approach at the atomic scale to predict irradiated microstructure evolution at long time scales beyond the reach of traditional atomistic simulations NuMat formed in association with Journal of Nuclear Materials serves as an umbrella for international meetings on nuclear materials science for fission reactors including the nuclear fuel cycle and is intended to be an international key scientific forum in the field Professor Bilge Yildiz appointed to the Rasmussen Chair in Nuclear Science and Engineering Assistant Professor Bilge Yildiz has been named Norman C Rasmussen Assistant Professor of Nuclear Science and Engineering The two year Rasmussen professorship is a career development chair designed to give younger faculty members an opportunity to establish their research activities and lay the foundation for future advances in their field Professor Yildiz s research focuses on understanding the fundamental relations between surface structure microchemistry electronic structure and activity in electrochemically active material interfaces By elucidating the mechanisms governing interface reactivity at the atomistic level Professor Yildiz and her colleagues hope to be able to tailor these interfaces to the benefit of particular technologies of interest including both future generations of fuel cells and corrosion resistant alloys in nuclear reactors The Rasmussen Professorship was endowed by Institute alum Neil Rasmussen in honor of his late father Norman C Rasmussen a pioneering and widely admired NSE professor who served as department head from 1975 to 1981 Professor Rasmussen was lead author of WASH 1400 the influential 1975 report for the Nuclear Regulatory Commission which marked the first application of probabilistic risk assessment PRA to nuclear plant safety Spotlight on Professor Yildiz Three NSE students awarded DOE funded Science Graduate Fellowships Current NSE graduate student Christian Haakonsen and incoming students Mark Chilenski and John Hanson are among 15 MIT students awarded Science Graduate Fellowships by the Department of Energy s Office of Science The fellowship is part of a new initiative to encourage outstanding students to choose careers in science and to support basic research by young scientists in a variety of fields including biology chemistry physics computational science engineering environmental sciences and mathematics Christian Haakonsen s interests range from plasma physics and fusion energy to neutron stars He is currently engaged in research that explores using particle in cell codes to study ion collecting probes objects in flowing magnetized plasmas Mark Chilenski s graduate research will focus on the Levitated Dipole Experiment LDX a unique plasma confinement device that uses an inductively charged magnetically levitated superconducting magnet in the middle of the plasma to provide a poloidal magnetic dipole field John Hanson s research interests lie in energy policy and solutions to the nation s energy challenges He will focus on the advancement of nuclear power as an integral part of the future energy solution Mark Chilenski and John Hanson will join the Department in Fall 2010 This is the first year of DOE s Science Graduate Fellowship Program which will support 150 students nationwide The exceptionally talented students selected as graduate fellows are part of our nation s next generation of scientific and technical leaders said DOE Secretary Chu This investment in the training of scientists and engineers is part of the Administration s continued effort to ensure that America has the scientific and engineering workforce we need to secure our energy future and our continued economic competitiveness Each fellow will be provided 50 500 per year for up to three years to support tuition living expenses research materials and travel to research conferences or to Department of Energy scientific user facilities L to R DOE Science Fellows Christian Haakonsen Mark Chilenski and John Hanson Three NSE graduate students win DOE sponsored awards Graduate students Mark Massie Robert Petroski and Jeremy Roberts of the Department of Nuclear Science and Engineering have been named winners of the 2010 Innovations in Fuel Cycle Research Awards sponsored by the Department of Energy DOE This new award program is designed to facilitate innovation the creation of new ideas and education in fuel cycle relevant disciplines Students were judged on published or submitted papers in any of the following eight categories Nuclear Science and Engineering Fuel Separations and Waste Forms Advanced Materials Nuclear Fuels Isotope Transmutation Nuclear Material Accountability and Control Instrumentation Systems Engineering and Analysis and Energy Policy with a focus on Nuclear Energy Robert Petroski and Mark Massie placed first and second respectively in the Isotope Transmutation category Jeremy Roberts placed second in the Nuclear Science and Engineering category All three will receive cash prizes and will present their work at the 2010 ANS Winter Meeting L to R Award winners Mark Massie Robert Petroski and Jeremy Roberts learn more about the award NSE Prof Ronald Ballinger appointed to the MWRA Independent Review Panel On June 29 2010 the Board of Directors of the Massachusetts Water Resource Authority MWRA appointed a three member independent panel of experts that will examine the circumstances that led to the loss of the insulating coupling along a section of the MetroWest Water Supply Tunnel This failure resulted in a boil water order for 30 Eastern Massachusetts communities The expert panel is chaired by President Zorica Pantic President of Wentworth Institute of Technology It includes Ronald Ballinger Professor of Nuclear Science and Engineering and Materials Science and Engineering at MIT and Director of the H H Uhlig Corrosion Laboratory and John H Bambei Jr Chief of Engineering for Denver Water and Chairman of the American Waterworks Associations Committee on Steel Pipe This independent review panel will prepare a report of its findings and recommendations about the design construction and other defects or deficiencies that may have contributed to the failure of the affected section of the tunnel It will include any evidence that may allow MWRA to pursue cost recovery efforts and will also make general recommendations about the design installation and testing of past and future pipe coupling systems MWRA press release Former nuclear engineering head Mason dies at 85 Edward A Mason a former head of the Department of Nuclear Engineering died at his home in Osterville Mass on June 23 He was 85 Mason joined the faculty of the Nuclear Engineering Department at its formation in 1957 having previously served as an Assistant Professor of Chemical Engineering He served as department head from 1971 to 1975 He was a U S Navy veteran and received his master s and doctorate degrees in chemical engineering from MIT after serving in World War II In 1974 President Gerald Ford appointed Mason as a commissioner on the first Nuclear Regulatory Commission He began his government service in January 1975 when the Commission was formally established He subsequently served as Vice President for Research at Amoco Corporation Mason was a member of the National Academy of Engineering and the New York Academy of Sciences fellow of the American Academy of Arts and Sciences American Nuclear Society and the American Institute of Chemists and member of the American Institute of Chemical Engineers the American Chemical Society and the American Association for the Advancement of Science Richard K Lester the current head of the Nuclear Science and Engineering department noted the influential role played by Mason in the early years of the department Ed was an outstanding figure in the development of the nuclear engineering discipline Together with Manson Benedict and their students he shaped the field of nuclear chemical engineering And even after leaving the Department Ed continued over many years to provide valuable advice and counsel to us He will be greatly missed MIT News Office MIT partners in DOE funded Nuclear Energy Innovation Hub MIT is one of nine partners in a new Nuclear Energy Innovation Hub announced by U S Deputy Secretary of Energy Daniel Poneman on May 28 The Hub also known as the Consortium for Advanced Simulation of Light Water Reactors CASL will be led by Oak Ridge National Laboratory and in addition to MIT includes partners from universities industry and other national labs It will use advanced capabilities of the world s most powerful computers to make significant leaps forward in nuclear reactor design and engineering A major focus of the MIT researchers will be to model the behavior of key materials such as fuel and fuel cladding together with energy generation and transport processes so as to provide better estimates of how these materials will perform within the extreme environment of a nuclear reactor The Nuclear Energy Innovation Hub will receive up to 122 million over five years and is the first of three Hubs expected to be announced by the Department of Energy this year The MIT team is led by three Nuclear Science and Engineering professors the PI Professor Mujid Kazimi Director of the Center for Advanced Nuclear Energy Studies and the co PIs Professors Sidney Yip and Jacopo Buongiorno The Oak Ridge based Innovation Hub will be guided by a Board of Directors headed by Professor Ernest Moniz of the MIT Energy Initiative on which Prof Kazimi will also serve The MIT team brings together faculty and research staff from Nuclear Science and Engineering Profs Benoit Forget and Bilge Yildiz and Dr Aydin Karahan as well as Profs Kazimi Yip and Buongiorno Materials Science and Engineering Profs Michael Demkowicz and Jeff Grossman and Civil and Environmental Engineering Prof John Williams Read DOE press release Bill Gates I love nuclear During his recent visit to MIT Bill Gates asked an audience of students and faculty a basic question Are the brightest minds working on the most important problems While his talk focused on health care in the developing world and the U S education system in the question session that followed the discussion shifted to the future of energy Matthew R Denman a graduate student in the Department of Nuclear Science and Engineering asked Gates about the future of nuclear power referring to TerraPower a company with a design for a new kind of reactor using depleted uranium in which Gates is a lead investor Gates firmly declared himself to be pro nuclear the coolest of all He contrasted nuclear technology with what he called cuddly technologies like wind and solar which require large amounts of land and generate energy only intermittently I love nuclear he said and called for more innovation in nuclear power plants One of the biggest challenges facing the nuclear engineers at TerraPower and throughout the nuclear power industry is to develop materials including fuels that are capable of performing efficiently and reliably in high radiation fields over long periods At NSE several faculty are working on materials related problems in radiation environments in some cases in collaboration with colleagues in the Department of Materials Science and Engineering In NSE Sidney Yip Bilge Yildiz Ron Ballinger Mujid Kazimi Jacopo Buongiorno Dennis Whyte In DMSE Linn Hobbs Michael Demkowicz Prof George Apostolakis sworn in as Commissioner of NRC Nuclear Regulatory Commission Chairman Gregory B Jaczko today administered the oath of office to the newest Commissioner Dr George Apostolakis in a ceremony at NRC headquarters in Rockville Md The addition of Apostolakis a professor of nuclear science brings the agency to its full complement of five commissioners for the first time since 2007 He joins the other Commissioners Kristine L Svinicki William D Magwood and William C Ostendorff Both Magwood and Ostendorff were sworn in April 1 I m looking forward to the Commissioner joining our discussions about important policy issues facing the agency and the nation said Jaczko He brings an exceptional background and talent to the NRC His insights and experience will strengthen our decision making and help us to continue to meet our critical mission to protect public health safety and the environment Nuclear safety has been at the center of my career and I look forward to working with my fellow commissioners to shape policy on the important regulatory issues facing the agency said Apostolakis who is a former member and chairman of the statutory Advisory Committee on Reactor Safeguards at the NRC Before joining the NRC Apostolakis was the Korea Electric Power Corporation professor of Nuclear Science and Engineering and a professor of Engineering Systems at the Massachusetts Institute of Technology He is the founder of the International Conferences on Probabilistic Safety Assessment and Management and received the Tommy Thompson Award for his contributions to improvement of reactor safety in 1999 and the Arthur Holly Compton Award in Education in 2005 from the American Nuclear Society He was elected to the National Academy of Engineering in 2007 The NRC commissioners have five year terms each staggered one year apart Apostolakis was confirmed to a term that ends June 30 2014 watch ceremony NSE Alum Roderic I Pettigrew Ph D 77 elected to the National Academy of Engineering Roderic I Pettigrew Director of the National Institute of Biomedical Imaging and Bioengineering has been elected to the National Academy of Engineering Dr Pettigrew was recognized for the use of MRI in human blood flow studies and leading advancements in bioengineering research and education as the initial director of NIBIB Dr Pettigrew received his Ph D in Nuclear Engineering from MIT in 1977 and was a student of the late Professor Gordon Brownell He subsequently received an M D from the University of Miami School of Medicine in an accelerated two year program served an internship and residency in Internal Medicine at Emory University and completed his residency in Nuclear Medicine at the University of California San Diego Dr Pettigrew then spent a year as a Clinical Research Scientist with Picker International the first manufacturer of MR equipment In 1985 he joined Emory as a Robert Wood Johnson Foundation Fellow focusing in non invasive cardiac imaging A renowned physician and nuclear physicist Dr Pettigrew is well known for his pioneering research involving four dimensional imaging of the heart using magnetic resonance imaging He has been a Professor of Radiology Medicine Cardiology at Emory University as well as Professor of Bioengineering at the Georgia Institute of Technology He also served as Director of the Emory Center for Magnetic Resonance MR Research at Emory University School of Medicine in Atlanta Georgia With his election to the National Academy of Engineering Dr Pettigrew becomes the first member of the NIH community to be elected to both the NAE and the Institute of Medicine IOM an honor he received in 2007 The IOM is renowned for its research program and serves as an honorific organization whose members are elected for their excellence and professional achievements Election to the IOM is considered one of the highest honors in the fields of medicine and health The National Academy of Engineering NAE a member of the National Academies has peer elected members who are among the world s most accomplished engineers and physical scientists The NAE was founded to provide engineering leadership in service to the nation and election to the NAE is one of the highest professional distinctions accorded to an engineer The Academy honors those who have made outstanding contributions to this scientific and educational discipline Dr Pettigrew is one of 68 new members elected nationwide in 2010 read about MIT faculty and Alums elected to NAE John Rowe delivers opening keynote at MIT Energy Conference by Ashley Finan PhD Candidate NSE John W Rowe CEO of Exelon Corporation delivered the opening keynote address at the MIT Energy Conference this Saturday March 6th Exelon is the largest nuclear operator in the U S and has announced an ambitious goal to reduce offset or displace 15 million tons of its greenhouse gas emissions more than its carbon footprint in 2001 by 2020 Rowe s address focused on the need for a carbon pricing mechanism through either a carbon tax or a cap and trade system with an escalating maximum cost of carbon He stressed that the current system of portfolio standards and other incentives can contribute by encouraging new technologies and re starting old ones but that this can be neither efficient nor effective in reducing emissions without the involvement of the market Rowe also commented that new nuclear plants cannot be sited or built without a strong public consensus and that no federal regulation can change that When asked about bringing innovation to the nuclear industry Rowe highlighted a conundrum faced by the nuclear industry in its drive for revival namely that innovation and standardization don t naturally come together They re awkward bedfellows Nonetheless Rowe confirmed

    Original URL path: http://web.mit.edu/nse/news/2010/index.html (2016-02-01)
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  • MIT NSE: Faculty: Areg Danagoulian
    along with developing fusion energy among its fourteen challenges If the peaceful use of fission energy is to continue taking place then we are faced with issues of proliferation and arms control Nuclear Security is a broad field which includes active and passive interrogation of commercial cargoes and public areas with the aim of preventing nuclear terrorism nuclear safeguards nuclear nonproliferation treaty verification andarms controls Nuclear Security monochromatic sources for cargo inspection A common method of inspecting commercial cargoes for the presence of fissile materials involves the use of 1 10MeV bremsstrahlung photon beams While simple and reliable this technique has many downsides such as the large doses involved and its relative inefficiency at triggering NRF and photofission Much progress in the field of active interrogation can be achieved by developing monochromatic and possibly tunable gamma sources monochromatic or quasi monochromatic sources will allow for lower dose radiography and photofission based active interogation tunable sources will increase the signal dose for NRF applications and will potentially reduce the required measurements times Currently a collaboration lead by MIT is exploring the possibility of using proton and deuteron beams in 11 B d nγ 12 C and 12 C p p γ 12 C reactions which produce highly monochromatic photons This program makes use of a 3MeV deuteron source at MIT Bates linear accelerator to experiment with d nγ reactions This approach can be used not only to achieve low dose radiography but also low dose dual energy radiography and lower dose photofission for fissionable material detection Nuclear Security nuclear arms reduction and treaty verification Arms reduction is an important part of improving global security The New START treaty limits the number of warheads to 1550 The participant states will then be required to demonstrate compliance while retaining the secrecy of weapons design This will involve proving to an inspection crew that the warheads being destroyed are real without releasing any direct nuclear or physical information about the weapon structure Zero knowledge detectors have been proposed to solve this puzzle The zero knowledge proof is an abstract concept which answers a simple yes no question without revealing any additional information Various zero knowledge detection concepts have been proposed These include the use of neutron radiography as well as reference foil NRF measurements The reference foil in this case will produce an NRF signal which is a convolution of the weapon s and reference foil s isotopic makeup This data is then compared to that from measurements taken on a warhead of known authenticity This comparison tests the hypothesis that the two weapons are identical A successful test will help verify the authenticity of the first weapon Additionally other concepts of zero knowledge detection are being studied and considered Patents Photon Induced Neutron Time Correlations in Special Nuclear Materials ROI submitted Peer Reviewed Publications D J Hamilton A Shahinyan et al An electromagnetic calorimeter for the JLab real Compton scattering experiment Nuclear Instruments and Methods Vol 643 Issue 1 1 July 2011 pp

    Original URL path: http://web.mit.edu/nse/people/faculty/danagoulian.html (2016-02-01)
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  • MIT NSE: Faculty: R. Scott Kemp
    on space arms control cyber security and methods for detecting covert nuclear weapon programs Proliferation Dynamics of Uranium Enrichment Most policies designed to prevent the spread of nuclear weapons were developed in a time when nuclear reactors dominated the proliferation landscape Today that has changed Five of the six most recent nuclear weapon aspirants chose uranium enrichment as the means of producing fissile materials for weapons Enrichment technologies play by different rules and challenge the international security framework in new and difficult ways Science based characterization of enrichment systems helps to provide strong boundary conditions under which one can evolve policy approaches that better fit today s nuclear security realities Detection of Undeclared Nuclear Activities Verification of peaceful activities is a fundamental tenet of today s nuclear security regime It is widely viewed as an essential element of any arms control agreement and one of the principal benefits of the Nuclear Non Proliferation Treaty The ability to verify the absence of undeclared activity however is increasingly difficult as nuclear technologies become smaller cleaner and more efficient Unless the current verification gap is bridged new international agreements in nonproliferation and arms control cannot be effectively negotiated under old conceptions of verification Either new ways of detecting clandestine nuclear facilities must be developed or a new understanding of the value of limited verification needs to be articulated By using a science based approach we seek to identify areas rich for development as well as understand better the hard limits to verification The Social Construction of Nuclear Power and Security Both nuclear power and the problem of nuclear proliferation are inseparable from the social systems in which they exist Science based approaches can identify hard limits on policy options but are insensitive to social constraints By studying the history of the proliferation nonproliferation

    Original URL path: http://web.mit.edu/nse/people/faculty/kemp.html (2016-02-01)
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  • MIT NSE: Research Staff: Richard C. Lanza
    EVENTS LNSP Seminar Series Rose Lecture Doctoral Research Expo Rising Stars in NSE Del Favero Prize ABOUT NSE at a glance WNSE History FAQ Diversity and Equity NSE Spotlights FUTURE OF NUCLEAR ENERGY Nuclear Fuel Cycle Report Nuclear Power Report ANS mitnse com SUPPORT NSE Mujid S Kazimi Memorial Fund Michael J Driscoll Graduate Fellowship Joseph P Kearney Memorial Fund NSE Spotlights NSE Policies Employees visitors Students Jobs For Students

    Original URL path: http://web.mit.edu/nse/people/research/lanza.html (2016-02-01)
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  • MIT NSE: Faculty: Paola Cappellaro
    experimental techniques and the coherent control theory of quantum bits qubits as well as to gain a deeper knowledge of the mechanisms of decoherence which must be studied and fought against Below are some projects that my group is working on Control of quantum registers with NV centers in diamond The Nitrogen Vacancy NV center has recently emerged as a versatile tool for magnetic resonance quantum optics precision measurement and quantum information processing The NV center is a localized impurity in diamond consisting of a nitrogen substitutional atom close to a vacancy Single NV centers are addressed using optical scanningconfocal microscopy and can be efficiently prepared manipulated and measured with optical and microwave excitation even at room temperature The system comprising the NV electronic spin and close by nuclear spins N and 13 C is an excellent candidate for the implementation of small quantum registers capable of simple quantum algorithms with very high fidelities These quantum registers can then in turn be connected via photon entanglement or direct dipole dipole coupling In this project we will develop high fidelity methods for controlling the electronic nuclear spin system Diamond magnetometer and precision metrology In recent years metrology and quantum information science have emerged as complementary areas of research We aim at applying the principles of quantum information science to the development of nano scale magnetic field sensors based on single spin qubits in diamond We focus on improving the diamond magnetometer readout enhancing its coherence improving its spatial resolution and devising strategies to achieve sensitivity beyond the Heisenberg limit Ideas and techniques from quantum information science are critical in achieving these goals from quantum non demolition measurement to dynamical decoupling and spin squeezing Quantum simulation and transport of quantum information A system composed of nuclear or electronic spins could play an important role complementary to cold atoms and molecules in the simulation of condensed matter systems For example well known NMR pulse sequences can be used to experimentally simulate the transport of quantum information in room temperature linear chains of spins coupled by the dipolar interaction The next step is to demonstrate transport of information between quantum registers via quantum wires in a highly mixed state We will use solid state NMR to study simulations and information transport in large spin systems Patents Electronic spin based enhancement of magnetometer sensitivity application 12 746 128 publication US 2010 0315079 A1 filed Dec 3 2008 inventors Mikhail Lukin Ronald L Walsworth Amir Yacoby Paola Cappellaro Jake Taylor Liang Jiang Lillian Childress Recent Publications A Ajoy U Bissbort M D Lukin R L Walsworth and P Cappellaro Atomic Scale Nuclear Spin Imaging Using Quantum Assisted Sensors in Diamond Phys Rev X 5 011001 2015 C D Aiello M Allegra B Hemmerling X Wang and P Cappellaro Algebraic synthesis of time optimal unitaries in SU 2 with alternating controls ArXiv 1410 4975 2014 C D Aiello and P Cappellaro The NV center as a quantum actuator time optimal control of nuclear spins ArXiv 1410 5641

    Original URL path: http://web.mit.edu/nse/people/faculty/cappellaro.html (2016-02-01)
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  • MIT NSE: Faculty: Alan Pradip Jasanoff
    the MIT faculty in 2004 he was a Whitehead Fellow at the Whitehead Institute for Biomedical Research at MIT Research Pushing the frontiers of MRI Functional magnetic resonance imaging fMRI has revolutionized our understanding of the human brain but the method is now approaching the limit of its capabilities Alan Jasanoff hopes to break through this limit and to develop new technologies for imaging the molecular and cellular phenomena that underlie brain function Beyond blood flow Functional MRI takes advantage of the fact that when a particular brain region becomes more active it consumes more oxygen and blood flow increases to that region increases to compensate These changes can be detected during a brain scan because the blood protein hemoglobin changes its magnetic properties when it is depleted of oxygen Although fMRI has yielded much valuable information it suffers from two fundamental limitations First changes in the blood are slow relative to the speed of neural activity making it impossible to measure rapid brain events Second the source of the activity can only be localized to the nearest blood vessel It is not precise enough to provide detailed information about activity in specific neurons and circuits Jasanoff is working to overcome these limitations He is devising new contrast agents whose magnetic properties are altered by events in the neurons themselves rather than their surrounding blood vessels If successful such an approach could reveal an unprecedented level of information about brain activity as it unfolds in real time The next generation of contrast agents When neurons become active they rapidly take up calcium from their environment Jasanoff hopes to visualize these rapid changes using magnetic nanoparticles that are coupled to a calcium binding protein In collaboration with colleagues at the MIT chemistry department he is also developing a new class of

    Original URL path: http://web.mit.edu/nse/people/faculty/jasanoff.html (2016-02-01)
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  • MIT NSE: Spotlight: Doctoral students seek quantum control in Prof. Cappellaro’s Quantum Engineering Group
    to get control of quantum systems and be able to exploit them to build quantum devices says Cappellaro The common theme is using nitrogen vacancy NV centers in diamonds as a promising experimental platform for this goal NV centers a type of crystal defect allow access to nearby electrons and their intrinsic angular momentum or spin Applications could include leveraging spin to create quantum bits qubits for information processing and storage which would provide exponential increases in computing power and using NV containing diamonds as ultra responsive sensors able to map molecular structures or monitor nano scale magnetic fields like those created by brain functions There are many hurdles One is that spin cannot be completely isolated and is subjected to deleterious noise This can lead to the decay of quantum superposition or decoherence which represents one of the major challenges to quantum control Doctoral student Masashi Hirose hopes to help solve the decoherence problem by learning how to use the electronic spin of NV centers to control the spin of nearby atomic nuclei nuclear spin The nuclear spin is much harder to control directly than the electronic spin but it s more resistant to noise and can stay in a superposition state for milliseconds rather than microseconds a 1000X increase explains Hirose The nuclear spin can act as an auxiliary qubit to protect the electronic spin from decoherence Thus the nuclear spin is a good candidate for memory functions in quantum computing while computation could be handled with the electronic spin Development of a control theory for interactions between the two is a research priority for Hirose who joined Cappellaro s lab group in 2009 after undergraduate work in Japan The subject matter is a dream for me and the QEG environment is very cooperative everyone shares their problems he says I meet with Paola at least every couple of days and she always welcomes new ideas and helps figure out next steps Fellow doctoral student Alexandre Cooper Roy is also focused on leveraging the NV center electronic spin and extending today s rudimentary control abilities to create quantum resources like multiple qubit computing structures or sensors NV centers are interesting because we can use them to control and read out the electronic spins associated with other impurities in the diamond lattice says Cooper Roy Now we d like to be able to put a few of these objects together so that we can do things that aren t currently accessible but the dynamics become really complicated Cooper Roy who has studied in Japan and France as well as his native Canada notes that the QEG s research approach emphasizes work at room temperature using relatively simple equipment which makes it possible for individuals to manage projects A student can come here and build an experiment from scratch it s an easy test bed for exploration of quantum mechanics he says It s great for training and for seeking practical applications MIT is a great experience because there s

    Original URL path: http://web.mit.edu/nse/news/spotlights/2014/qeg.html (2016-02-01)
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