plasma science & fusion center: physics research

8/3/2019 Plasma Science & Fusion Center: Physics Research

1/4

T h e P l a s m a S c i e n c e & F u s i o n C e n t e r M a s s a c h u s e t t s I n s t i t u t e o f T e ch n o l o g y

Understanding the basic physics o plasmas is necessary not only to advance usion research, but to increase

the physics-based oundations o plasma-related scientifc disciplinesand applications.

Members o the Physics Re-

search Division, including

theoretical and experimen-

tal plasma physicists, aculty mem-

bers, graduate and undergraduatestudents and visiting collaborators,

work together to better understand

plasmas and to extend their uses.

Theoretical Plasma PhysicsUsing the undamental laws o

physics, theorists at the PSFC are

developing improved analytical and

numerical models to better describe

plasma phenomena both in the

laboratory and in nature. Teoreti-

cal plasma research is essential not

only to better understand basic

plasma physics, but also to sup-

port many areas o usion physics.

In addition to basic plasma theory,

topics being pursued at the PSFC

include tokamak research on radio

requency heating and current drive,

core and edge transport and turbu-

lence, and magnetohydrodynamic and

kinetic stability. Tis research sup-

ports the PSFC tokamak, Alcator C-

Mod, and the Levitated Dipole Experi-ment (LDX), as well as other such

experiments around the world.

Interaction between MI research

sta and scientists at other acilities

osters vital scientic collaborations in

the US and abroad.

MI Teorists also investigate concepts

to improve tokamak perormance. One

promising approach to advanced

tokamak operation uses radio requency

waves to control pressure and current

proles in order to control instabilities

and achieve steady state operation in

high pressure plasmas.

In the area o inertial connement

usion (ICF), theorists study the

ablation process, during which a

plasma is created that causes nonlin-ear scattering o the laser light. Tis

scattering not only reduces how

eciently the target can be heated, but

also generates hot electrons that can

preheat the core, inhibiting compres-

sion. PSFC theorists ocus on under-

standing experimental observations o

scattered light due to laser-plasma

interactions, hoping to nd ways to

control the deleterious eects o these

phenomena.

Ph

otobyPaulRivenberg

Dr. Jan Egedal works atop the Versatile Toroidal Facility, a medium-sized tokamak currently

used to study magetic reconnection, a phenomenon observed in solar ares.

Research includes:

Laboratory experiments

Development o novel

plasma diagnostics

Theory o magnetically

confned usion plasmas

Nonlinear wave

propagation, turbulence

and chaos

Space plasma physics

Plasma astrophysics

Laser-plasma interactions

Physics ReseaRch

T h e P l a s m a s c i e n c e & F u s i o n c e n T e r m a s s a c h u s e T T s i n s T i T u T e o F T e c h n o l o g y


2/4

Experimental Plasma PhysicsExperiments are conducted both on-

site at the PSFC, on small-to-medium-

scale experimental devices, and o-

site, on large-scale national and

international usion devices.

Levitated Dipole Experiment

Physicists at the PSFC are exploringnovel magnetic connement congu-

rations that are undamentally di-

erent rom the tokamak. Tese may

lead to alternate reactor concepts,

and provide insights into space and

astrophysical processes. One such

approach, which uses a levitated cur-

rent-carrying superconducting ring,

is being pursued as a collaboration

with Columbia University. Such a

current ring generates a dipole type

magnetic eld geometry, which in turnconnes a torus o hot plasma. Dipole

connement is observed in nature to

be robust (e.g., in the magnetosphere

around the planet Jupiter). Tis Levi-

tated Dipole Experiment (LDX) will

improve our understanding o dipole

connement in a laboratory setting.

Experiments include:

exploring new

confnement concepts,

such as the Levitated

Dipole Experiment;

developing new

diagnostics or measuring

plasma parameters;

investigating space

physics phenomenathrough laboratory

simulations and o-site

ionospheric observations;

developing novel

diagnostics or inertial

confnement (ICF)

physics experiments;

exploring novel scientifc

uses o plasma phenomena.

DOE Ofce o Fusion Energy Director o Research John Willis and MIT Associate Provost Alice

Gast cut the ribbon or the Levitated Dipole Experiment, joined by members o the LDX team.

Graduate students working on the project sit atop the vacuum chamber.

Nuclear Engineering Proessor Jerey Freidberg

(above let), Associate Director o the PSFC,

teaches plasma physics-related courses and

supervises student theses.

Many theorists work with

graduate students on

cutting edge research.

Dr. Peter Catto advises

Natalia Krasheninnikova,

who is studying plasma

stability. Some o Dr.

Cattos research ocuses

on how the electric feld

is established in both the

edge and core o toka-

maks like Alcator C-Mod,

MITs premier

usion experiment.

PhotobyMPMcNally

Dr. Abhay Ram combines teaching with

research in the areas o plasma heating and

current generation by radio requency waves,

nonlinear plasma dynamics, space plasma

physics, and laser-plasma interactions.


3/4

Phase Contrast Imaging on

DIII-D and C-Mod

It is now widely believed that micro-

turbulence in magnetically conned

usion plasmas results in excessive loss

o particles and heat. o better under-

stand such turbulence, PSFC research-

ers have developed a new diagnosticusing CO

2lasers and a special imaging

technique widely used in microscopy

- phase contrast imaging. Tis diagnos-

tic, which provides detailed measure-

ments o the density fuctuations with

extraordinary sensitivity and ne

spatial and temporal resolution, is

being used to study turbulence and

RF waves on the DIII-D tokamak in

San Diego, and on the Alcator C-Mod

tokamak at the PSFC. Recent up-

grades will allow tests o some o thelatest theoretical predictions regard-

ing the stabilization o microturbu-

lence, leading to improved conne-

ment and RF wave propagation.

Magnetic Reconnection

Research sta and students investigate

magnetic reconnection using the

Versatile oroidal Facility (VF), a

toroidal acility built largely by

graduate and undergraduate students

and PSFC sta. Magnetic reconnec-

tion is the breaking and reconnecting

o magnetic eld lines interacting with

plasma. Reconnection controls the

spatial and temporal evolution o

explosive plasma phenomena such as

solar fares, coronal

mass ejections and

internal disruptions

in magnetic usion devices. VF has

made it possible to measure the

plasma response to reconnection with

unprecedented accuracy in the

laboratory, stimulating the develop-

ment o new theoretical models or

reconnection.

Joint European Torus (JET)

Tis program conducts collaborative

experiments at the Joint European

orus (JE) in England, the world's

largest tokamak and the major

experimental tool o the European

Fusion Development Agreement. In

MIT undergraduates work with the All Sky Imaging System (ASIS) designed to diagnose plasma

turbulence occuring in space and laboratory plasmas. ASIS can record inrared, visible, and ultra-violet emissions to determine the profles o plasmas and the structures o plasma turbulence.

JET, in England, is the

largest tokamak in the

world, and is improving

understanding o plasma

stability and transport.

these experiments researchers study

instabilities driven by high-energy

particles, such as radio requency-

driven energetic ions and usion-gen-

erated alpha-particles. Tese studies

lead to an improved understanding

o plasma stability and transport that

will be important in a burning plasma

experiment such as the internationalcollaboration IER, where the u-

sion process generates a substantial

alpha-particle component. Te results

o our research have claried the

relation between these waves and the

plasma to such a point that inorma-

tion about some o the plasma's most

important parameters can be ob-

tained rom the wave measurements.


4/4

Plasma Science & Fusion Center 77 Masssachuset ts Ave., Cambridge, MA 02139 Ph: 617.253.8100 Fax: 617.253.0570 [email protected] ww w,psc.mit.edu/

Ionospheric Plasma Research

Researchers and students in this

program perorm eld and laboratory

experiments to understand plasma

turbulence due to radio requency

heating. Tey travel to Alaska, PuertoRico and other sites or their investi-

gations. Students use the Ionospheric

Radar Integrated System (IRIS) at

Millstone Hill, Massachusetts, or

remote sensing o space plasma turbu-

lence, and the All Sky Imaging System

(ASIS), to study the spatial structures

o this turbulence. Understanding

turbulence will aid satellite communi-

cations, and will help control plasma

turbulence in uture usion devices.

Laser-Plasma Interaction

Te Division is collaborating with the

University o Rochester Laboratory or

Laser Energetics (LLE) and theLawrence Livermore National Labora-

tory (LLNL). Tis eort is designed to

provide extensive diagnostic inorma-

tion about Inertial Connement

Fusion (ICF) plasmas by making

spectral, spatial, and temporal

measurements o charged usion

products with novel instrumentation.

Current experiments on the OMEGAlaser acility at LLE have provided

inormation about usion yield, plasma

temperature and density, implosion

symmetry, implosion dynamics, burn

symmetry, stopping power o hot

plasmas, and laser-plasma interactions.

National Ignition Facility

PSFC scientists are also active in den-

ing the science that can be studied at

the uture National Ignition Facility

(NIF) at LLNL. Tis $2.1 billion acility

will ultimately be the center or inertial

usion research in the US. NIF will

oer unique opportunities to explore

the properties o matter under extreme

pressures (~500 billion atmospheres)

and densities (~1000 g/cm3). PSFC

One o the noveldiagnostics PSFCscientists have developed

or the National Ignition

Facility (NIF) would use 31

MeV protons, generated

within the NIF capsule, to

help scientists determinewhether NIF has achieved

its goal o producing

substantial themonuclear

gain during pellet implosion.

PhotocourtesyofLLE

PSFC Group Leader Richard Petrasso (bottom right) looks on as the MIT-designed

charged particle spectrometer (upper right) is installed on the target OMEGA laser at

the University o Rochester Laboratory or Laser Energetics (LLE) .

scientists have developed two novel di-

agnostics or NIF that could be used inaddition to many o the charged-par-

ticle diagnostics they have developed

or OMEGA. Te rst new diagnostic

would use 31-MeV protons, gener-

ated within the NIF capsule, to help

scientists determine whether NIF has

achieved its goal o producing substan

tial thermonuclear gain during pellet

implosion. Te second new diagnostic

would measure the energy spectra o

usion neutrons that are downscat-

tered by the compressed capsules, to

determine the amount and symmetry

o capsule compression. Because this

diagnostic has a wide dynamic range i

will be useul during all stages o NIF

development, rom low-yield initial

experiments to high-yield ignition.

T h e P l a s m a s c i e n c e & F u s i o n c e n T e r m a s s a c h u s e T T s i n s T i T u T e o F T e c h n o l o g y

plasma science & fusion center: physics research

Documents