About
69
Publications
9,850
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,211
Citations
Introduction
Current institution
Publications
Publications (69)
A low-AC loss Rare-earth barium copper oxide (REBCO) cable, based on the VIPER cable technology has been developed by commonwealth fusion systems for use in high-field, compact tokamaks. The new cable is composed of partitioned and transposed copper ‘petals’ shaped to fit together in a circular pattern with each petal containing a REBCO tape stack...
Stresses developed in high field toroidal magnets based on high temperature superconductors are often limiting factors preventing further increase of magnetic fields. One of possible ways to reduce stresses is so called force-balanced magnets where non-planar coils are used. Proper orientation of coils can signicantly reduce and even cancel locally...
High-temperature superconductors (HTS) promise to revolutionize high-power applications like wind generators, DC power cables, particle accelerators, and fusion energy devices. A practical HTS cable must not degrade under severe mechanical, electrical, and thermal conditions; have simple, low-resistance, and manufacturable electrical joints; high t...
The past few years have seen a renewed interest in the search for light particle dark matter. ABRACADABRA is a new experimental program to search for axion dark matter over a broad range of masses, 10−12≲ma≲10−6 eV. ABRACADABRA-10 cm is a small-scale prototype for a future detector that could be sensitive to QCD axion couplings. In this paper, we p...
The axion is a promising dark matter candidate, which was originally proposed to solve the strong-CP problem in particle physics. To date, the available parameter space for axion and axionlike particle dark matter is relatively unexplored, particularly at masses ma≲1 μeV. ABRACADABRA is a new experimental program to search for axion dark matter ove...
Composite Technology Development, Inc. (CTD), in partnership with the Plasma Science and Fusion Center (PSFC) at MIT recently developed and demonstrated a re-makeable, insulated HTS cable joint for a Twisted Stacked-Tape Cable (TSTC). The prototype joint exhibited low tape-to-tape resistances
$(\rm \sim 400 n\Omega)$
with critical current through...
The past few years have seen a renewed interest in the search for light particle dark matter. ABRACADABRA is a new experimental program to search for axion dark matter over a broad range of masses, $10^{-12}\lesssim m_a\lesssim10^{-6}$ eV. ABRACADABRA-10 cm is a small-scale prototype for a future detector that could be sensitive to QCD axion coupli...
The axion is a promising dark matter candidate, which was originally proposed to solve the strong-CP problem in particle physics. To date, the available parameter space for axion and axion-like particle dark matter is relatively unexplored, particularly at masses $m_a\lesssim1\,\mu$eV. ABRACADABRA is a new experimental program to search for axion d...
Superconducting magnets have been widely used in medical devices for several decades, primarily in thousands of MRI systems worldwide. More recently superconducting magnets have begun to have a small but growing impact on a newer field of medical devices, namely cyclotron accelerators for hadron therapy. This is a form of radiation treatment that u...
The Massachusetts Institute of Technology has been collaborating with the Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare (INFN), in Catania, Sicily, on the conceptual design of a replacement magnet for the existing LNS cyclotron used by INFN. The existing magnet was built in the early 1980s. Future nuclear physics experiments r...
The Massachusetts Institute of Technology has been performing a preliminary study of superconducting magnetic energy storage (SMES) magnet configurations under a Pôle MecaTech Cluster collaboration sponsored by the government of the Walloon Region in Belgium. Consortium members include Ion Beam Applications S.A. (IBA), CE+T Power (CE+T), Euro-Diese...
Turn-key superconducting magnet systems are increasingly conduction-cooled by cryogenerators. Gifford-McMahon systems are reliable and cost effective, but require annual maintenance. A usual method of servicing is replacing the cold head of the cryocooler. It requires a complicated design with a vacuum chamber separate from the main vacuum of the c...
A cyclotron for ion acceleration is magnetically shielded during ion acceleration by passing electrical current in the same direction through both the first and second superconducting primary coils. A first magnetic-field-shielding coil is on the same side of the mid plane as the first superconducting primary coil, while a second magnetic-field-shi...
The Daeδalus experiment seeks to evaluate neutrino scattering effects that go beyond the standard model. Modular accelerators are employed to produce 800 MeV proton beams at the megawatt power level directed toward a target, producing neutrinos. The Superconducting Ring Cyclotron consists of identical sectors (currently 6) of superconducting dipole...
A magnet to study the properties of dusty plasmas in the presence of a magnetic field has been proposed. This magnet has four operating modes to vary the experimental test region and target magnetic field values. The design of the cold mass for the high field magnetized dusty plasma experiment is presented and analyzed. The cold mass includes four...
The ITER Central Solenoid (CS) magnet needs to be protected against overheating of the conductor in the event of the occurrence of a normal zone (NZ). Due to a large amount of stored energy and slow NZ propagation, the NZ needs to be detected and the switchyard needs to open the breakers within 2 s after detection of the NZ. The CS will be discharg...
We show that multiple sets of superconducting coils can be used to generate the magnetic field profile required in a synchrocyclotron, replacing the ferromagnetic pole pieces typically used in these machines. Coil number, location, and current are adjusted to produce the required field for particle acceleration. Superconducting coils are likewise u...
The conceptual design of the replacement solenoid for the 12 GeV upgrade at Jefferson Lab is analyzed structurally. First, stress distributions within a detailed cross-section of the winding pack under Lorentz and thermal loads are discussed. These stress distributions are used to evaluate the integrity of the copper conductor and fiberglass insula...
A 208-mm inner diameter, 62-mm-tall, wind-and-react Nb
<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>
Sn prototype magnet was tested to demonstrate its suitability for use in a compact superconducting cyclotron. The magnet and its 270 kg iron return yoke were cooled together by conduction usin...
The 12 GeV upgrade at Jefferson Lab includes plans for a new solenoid that will replace the existing solenoid made with the Large Aperture Superconducting Solenoid (LASS) coils from Stanford Linear Accelerator Center (SLAC). The conceptual design for the replacement solenoid presented here includes the magnetic design, winding arrangement, conducto...
A liquid nitrogen (LN2) is usually used to keep the high-temperature superconducting (HTS) cable low temperature. A pump is utilized to circulate LN2 inside the cryopipes. In order to minimize heat leakage, a thermal siphon circulation scheme can be realized instead. Here, we discuss the effectiveness of thermal siphon with counter-flow circulation...
In recent years, the technologies of manufacturing of high‐temperature superconducting
(HTS) tapes have achieved the critical current of 100 A. An era of industrial application of HTS power supply cables is coming. The liquid nitrogen (LN2) is usually used to keep the HTS cable at low temperature. LN2 must circulate inside the cryopipes, and the p...
In Chubu University, bellows pipes are applied to absorb the heat shrink as a part of straight pipes for superconducting power transmission lines (SC PT). In conventional SC PT systems, SC cables are put in corrugated pipe. Pressure drop of the liquid nitrogen flow in bellows and corrugated pipes are analyzed by a fluid-analysis software. Pressure...
A NbTi charging coil (C-coil) for the levitated dipole experiment (LDX) was manufactured by the Efremov Institute for the LDX team. The C-coil is used to inductively charge and discharge the persistent-mode, Nb<sub>3</sub>Sn floating coil (F-coil) at the start and end of each series of plasma runs in the LDX. The intentional change of F-coil state...
Distributions of the velocity, the temperature and the pressure of a liquid nitrogen (LN2) flow are analyzed at hydraulic cross-sections on two types of superconducting power transmission lines (SC PT). One is on a DC-SC PT, the other is on a three phase AC-SC PT. Inflow heat from the pipe wall and the cables to LN2 are evaluated, however the heat...
The levitated dipole experiment (LDX) explores the physics of high-temperature plasmas confined by a dipole magnetic field. Stable high-beta plasma has been created and confined by the magnetic field of a superconducting coil. Discharges containing trapped electrons form when microwaves cause strong perpendicular heating at cyclotron resonance. To...
Fusion research in the United States is sponsored by the Department of Energy's Office of Fusion Energy Sciences (OFES). The OFES sponsors a wide range of programs to advance fusion science, fusion technology, and basic plasma science. Most experimental devices in the US fusion program are constructed using conventional technologies; however, a sma...
MECO, the muon-to-electron conversion experiment, requires a total of 96 superconducting solenoids designed for construction by industry and assembly into 4 separate cryostats following completion of final design. The magnet system has a 12 times 26 m installation footprint. The objective of the tolerances and uncertainties sensitivity studies was...
The Levitated Dipole Experiment (LDX) is an innovative facility to study plasma confinement in a dipole magnetic field, created by a superconducting solenoid (floating coil), which is magnetically levitated in the center of a 5 m diameter by 3 m tall vacuum chamber. The floating coil (F‐coil) consists of a Nb
3Sn magnet installed inside a strong ve...
The Levitated Dipole Experiment (LDX) is an innovative approach to explore the magnetic confinement of a fusion plasma offering the possibility of an improved fusion power source. In this concept, a magnetic dipole (a superconducting solenoid) is magnetically levitated for several hours at the center of a 5 m diameter, 3 m tall vacuum chamber. The...
The central solenoid for the International Thermonuclear Experimental Reactor (ITER), a fusion tokamak experiment with the goal of generating 500 MW of fusion power with high gain (Q>10), must provide most of the volt-seconds needed to induce and sustain a 15 MA plasma for burn times of >400 s. The 6.4 GJ central solenoid design requires a 45 kA co...
A three-dimensional (3D) design is presented of a non-axisymmetric periodic permanent magnet (PPM) focusing system which will be used to focus a large-aspect-ratio, ellipse-shaped, space-charge-dominated electron beam. In this design, an analytic theory is used to specify the magnetic profile for beam transport. The OPERA3D code is used to compute...
The Levitated Dipole Experiment (LDX) was developed to study plasma confinement in a dipole magnetic field.
Plasma is confined in the magnetic field of a 680‐kg Nb
3Sn Floating Coil (F‐coil) that is electromagnetically supported at the center of a 5‐m diameter by 3‐m tall vacuum chamber. The Levitation Coil (L‐coil) is a 2800‐turn, double pancake...
The Muon-to-Electron Conversion Experiment (MECO) seeks to detect muon to electron conversion, providing evidence that the conservation of muon and electron type lepton number can be violated. Observation of this violation would suggest physics beyond the Standard Model. The experiment is to be installed at Brookhaven National Laboratory (BNL). A h...
In a heavy ion fusion driver, arrays of superconducting quadrupoles will transport parallel beams through a sequence of induction acceleration cells. The development of such arrays is a unique and challenging task. Since magnetic transport is one of the most expensive subsystems, economy of fabrication is a primary consideration. A compact design i...
The Heavy Ion Fusion (HIF) Program is developing superconducting focusing magnets for both near-term experiments and future driver accelerators. In particular, single bore quadrupoles have been fabricated and tested for use in the High Current Experiment (HCX) at Lawrence Berkeley National Laboratory (LBNL). The next steps involve the development o...
The Central Solenoid Model Coil (CSMC) was designed and built from 1993 to 1999 by an ITER collaboration between the U.S. and Japan, with contributions from the European Union and the Russian Federation. The main goal of the project was to establish the superconducting magnet technology necessary for a large-scale fusion experimental reactor. Three...
The Levitated Dipole Experiment (LDX) is a novel concept that examines plasma compressibility as a method for stable magnetic confinement of fusion grade plasmas. The experiment uses a 0.8 m diameter ring-type dipole coil that is levitated at the center of a 5 m diameter × 3 m tall vacuum chamber to confine the plasma. This persistent mode, floatin...
The Maglifter is an electromagnetic catapult being considered by
NASA to reduce the cost of lifting a payload into space. The system
would accelerate a vehicle of up to 590 tonnes to a final velocity of
268 m/s at an acceleration of 2 g. Superconducting coils are considered
for levitation because they permit track-to-vehicle clearances of more
than...
The charging coil (C-coil) for the joint Columbia University/MIT
Levitated Dipole Experiment (LDX) is under development jointly by MIT
and the Efremov Institute. The NbTi superconducting C-coil serves to
charge/discharge inductively the floating superconducting magnet to/from
2277 A when it is resting in the charging port at the bottom of the LDX
v...
The Levitated Dipole Experiment (LDX) is an innovative approach to
explore the magnetic confinement of fusion plasma. A superconducting
solenoid (floating coil) is magnetically levitated for up to 8 hours in
the center of a 5-meter diameter vacuum vessel. The floating coil
maximum field is 5.3 T, and a react-and-wind Nb<sub>3</sub>Sn conductor
was...
The Levitated Dipole Experiment (LDX) is an innovative approach to
explore the magnetic confinement of fusion plasmas. A superconducting
solenoid (floating coil) is magnetically levitated for up to 8 hours in
the center of a 5-meter diameter vacuum vessel. This coil is supported
by a levitating coil (L-Coil) on top of the vacuum vessel. In the
init...
The inner and outer modules of the central solenoid model coil
(CSMC) were built by US and Japanese home teams in collaboration with
European and Russian teams to demonstrate the feasibility of a
superconducting central solenoid for ITER and other large tokamak
reactors. The CSMC mass is about 120 t; OD is about 3.6 m and the stored
energy is 640 M...
The Inner and Outer modules of the Central Solenoid Model Coil (CSMC) were built by US and Japanese home teams in collaboration with European and Russian teams to demonstrate the feasibility of a superconducting Central Solenoid for ITER and other large tokamak reactors. The CSMC mass is about 120 t, OD is about 3.6 m and the stored energy is 640 M...
Compact superconducting quadrupole magnets with a total length of
150 mm, an integrated gradient of about 13 T, and good field quality are
needed for the High Current Transport Experiment (HCX) at Lawrence
Berkeley National Laboratory. The Advanced Magnet Lab, Inc. has
developed a novel concept, called multi-cylinder coils, which is ideally
suited...
The Levitated Dipole
Experiment (LDX) will investigate stability and confinement of
high beta plasmas in a dipole configuration created by a superconducting
ring coil. In order to eliminate end losses, this coil will be levitated
and float in the middle of the LDX vacuum chamber, with the
gravitational forces counteracted by electromagnetic attract...
The Levitated Dipole Experiment (LDX) is a new, innovative
magnetic confinement fusion experiment being designed and installed in
collaboration with Columbia University at the Massachusetts Institute of
Technology (MIT). The primary objective of the experiment is to
investigate the possibility of steady-state, high-beta plasma
confinement with near...
The Levitated Dipole
Experiment (LDX) is designed to study high-β plasmas
confined by a magnetic dipole with near classical energy confinement.
LDX is currently under construction at MIT with first plasma operations
planned for the summer of 2000. The primary goal of the initial phase of
LDX operation is the study of plasma behavior near marginal s...
In the Levitated Dipole Experiment (LDX), a hot plasma is formed
about a levitating superconducting dipole magnet in the center of a 5 m
diameter vacuum vessel. The levitated magnet is suspended magnetically
during an eight hour experimental run, then lowered and recooled
overnight. The floating F-coil magnet consists of a layer-wound magnet
with 4...
The LDX Experiment, presently being designed and built at MIT, requires a superconducting coil that can be floated within a large vacuum chamber. The 90 cm diameter, 1.2 MA, Nb_3Sn floating coil utilizes a novel cryostat design. The >400 kg coil will float for up to 8 hours, centered within a 5 m diameter, 3 m tall vacuum chamber. When levitated fr...
The Korean Superconducting Tokamak Advanced Research (KSTAR) at
the Korea Basic Science Institute in Taejon will be the first Tokamak
with an advanced all superconducting magnet system, including toroidal
field (TF), poloidal field (PF),and field error correction (FEC) coils.
The conductors are all cable-in-conduit (CICC) superconductors with a
sin...
We have examined the heating of the cold structure of ITER while controlling the plasma shape and current. Specifically, the control circuits are responding to expected disturbances such as sawteeth, vertical displacements, etc. The computation involves the interaction between two codes. Corsica simulates the control and provides the perturbed plas...
A finite element, thermal analysis of the Tokamak Physics eXperiment's (TPX) toroidal field (TF) coil case is presented. The analysis models the 316LN coil case as a 3-D shell with imposed thermal loads dominated by neutron and eddy current heating. Heat sinks which simulate the flow of supercritical helium in the coil case cooling system and adjac...
The Tokamak Physics Experiment (TPX) at Princeton will be the first tokamak with an all superconducting poloidal field (PF) magnet system. The conductors are all cable-in-conduit (CICC) superconductors with a single conduit, similar to those in the International Thermonuclear Experimental Reactor (ITER). 10 of the PF coils use Nb<sub>3</sub>Sn supe...
The TPX magnet preliminary design effort is summarized. Key
results and accomplishments during preliminary design and supporting
R&D are discussed, including conductor development, quench
detection, TF and PF magnet design, conductor bending and forming,
reaction heat treating, helium stubs, and winding pack insulation
The toroidal field end cases and support structure for the TPX are
at cryogenic temperatures. The time varying currents in the poloidal
field coil system will induce eddy currents in these structures. The
associated Joule dissipation will cause local heating and require heat
removal which will show up as a load on the cryogenic system. Knowledge
of...
The Tokamak Physics Experiment (TPX) at Princeton will be the
first tokamak with an all superconducting magnet system, including both
the toroidal field (TF) and poloidal field (PF) coils. The conductors
are all cable-in-conduit (CIC) superconductors with a single conduit,
similar to those in the International Thermonuclear Experimental Reactor
(IT...
The poloidal field and the vertical stability control coil systems
for the Tokamak Physics Experiment (TPX) have time varying currents
which breakdown and initiate the plasma current, provide the volt
seconds necessary to ramp the plasma current to 2 MA, and maintain the
plasma shape and position. The effects of the 3-D eddy currents induced
in the...
The toroidal field coil and support structures for ITER are maintained at cryogenic temperatures. The time-varying currents in the poloidal field coil system will induce eddy currents in these structures. The associated Joule dissipation will cause local heating and require heat removal which will show up as a load on the cryogenic system. Studies...
The Tokamak Physics Experiment is designed to develop the scientific basis for a compact and continuously operating tokamak fusion reactor. It is based on an emerging class of tokamak operating modes, characterized by beta limits well in excess of the Troyon limit, confinement scaling well in excess of H-mode, and bootstrap current fractions approa...
Studies were carried out to determine Joule heating in and Lorentz forces acting on the GEM detector magnet LN radiation shields using the program EDDYCUFF. The effects seen during coil charge and discharge have been compared. Panels with various cooling tube configurations have been analyzed. Configurations include: electrically interconnected tub...
The Tokamak Physics Experiment is designed to develop the scientific basis for a compact and continuously operating tokamak fusion reactor. It is based on an emerging class of tokamak operating modes, characterized by beta limits well in excess of the Troyon limit, confinement scaling well in excess of H-mode, and bootstrap current fractions approa...
Joule heating of GEM detector magnet bobbins was analyzed in [2] without considering effects due to the presence of the thermosiphon cooling tubes. The results presented in this memo show that the impact of the tubing on the results of the above mentioned memo is small. They also show the currents and power deposition in the tubing jumpers between...
Joule heating of GEM detector magnet bobbins was analyzed in [1] without considering effects due to the presence of the thermosiphon cooling tubes. Later the tubing was introduced [2] into the analysis in the form of jumpers connecting the bobbin quadrants; the results showed that the impact of the tubing was small. This memo presents the results o...
