1 high energy density physics and the role of rhic ii barbara jacak stony brook april 29, 2005
TRANSCRIPT
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What is high energy density physics?
Map ofThe HEDUniverse
‘high energy density’: > 1011 J/m3
P > 1 MbarI > 3 X 1015W/cm2 Fields > 500 Tesla
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A “new” interdisciplinary research area
High Energy Density Physics is “area of significant promise”identified on basis of “Physics of the Universe”, etc.first area for agencies to:“develop a science-driven roadmap
that lays out the components of a national program”. National Task Force on HEDP
At request of Interagency Working Group* on the Physics of the Universe chartered under the National Science and Technology Council.
Goal: develop plans and set priorities in scientific areas that cut across agency lines within the federal government
Chair: Ron Davidson, Princeton Plasma Physics LabVice chair: Tom Katsouleas, USCNP members: Jacak, Zajc, Hallman (at workshop)
* NSF, DOE, NASA, NRL, NIST, OSTP
RBRC workshop on Dec.16, 17 2004
Strongly Coupled Plasmas:
Electromagnetic, Nuclear and Atomic
organizers: B. Jacak, S. Bass, E. Shuryak, T. Hallman, R. Davidson
An interdisciplinary “experiment”
opportunity to learn from each other
form new collaborations/directions
http://quark.phy.bnl.gov/~bass/workshop.htm
for program, slides
Thanks for support from RBRC & NSF!
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Plasma coupling parameter
Estimate = <PE>/<KE> using QCD coupling strength, g
<PE>=g2/d d ~1/(41/3T)
<KE> ~ 3Tg2 ~ 4-6 (value runs with T) ~ g2 (41/3T) / 3T so plasma parameter NB: such plasmas known to behave as a liquid!
Correlated or bound q,g states, but not color neutral
So the quark gluon plasma is a strongly coupled plasmaAs in warm, dense plasma at lower (but still high) TBut feels strong interaction rather than electromagnetic
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Other strongly coupled plasmas
Inside white dwarfs, giant planets, and neutron stars (n star core may even contain QGP)
In ionized gases subjected to very high pressures, magnetic fields, or particle interactions
Dusty plasmas in interplanetary space & planetary rings Solids blasted by a laser Properties of interest:
How do these plasmas transport energy?How quickly can they equilibrate?What is their viscosity? >10 can even be crystalline! How much are the charges screened? Is there evidence of plasma instabilities at RHIC? Can we detect waves in this new kind of plasma?
nove
l pla
sma
of
str
ong
inte
ract
ion
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gas of strongly interacting Li atoms
M. Gehm, S. Granade, S. Hemmer, K, O’Hara, J. Thomas Science 298 2179 (2002)
excite Feshbach resonance
weakly coupled
strongly coupled
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Plasma Diagnostics
Many of the interesting systems are short-lived!nanoseconds for laser-heated plasmasboth communities study space-time evolution through
time integrated observables (radiation or probes)
plasma folks can also measure time dependenceboth must figure out how to use correlations to extract
Transmission of external probes hard x-rays, electrons, or jets
Final state cluster distributions for early state infoDiagnostics of collective motionsMultiparticle emission variablesSingle particles in multiparticle field, acoustic waves
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From talk of Todd Ditmire (U. Texas)
Diagnostic quantity measured
Transmission of , hard x-rays density, atomic properties
Probe photon interference imaging, expansion velocity
Phase shifts of probe photon release velocity of expanding material
x-ray reflectivity image shock front
spectrum, time structure of hydrodynamic expansion
radiated clusters
Time-resolved absorption density profile with time
Electron radiation plasma oscillations
test hydro predictions
Anisotropy in radiation test calculations of field gradients
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Method using 3 lasers: 1) create shock, 2) x-rays, and 3) probe sample
Sapphire window
Beryllium foil
Metal pusher
Copper
D2
Shock
Radiograph x-rays
X-ray µscope
and streak
camera
Iron foil
1) Shock generating laser
3) Probe laser2) x-ray generating laser
R. Lee, S. Libby, LLNL
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Shock and interface trajectories are measured by x-ray radiography
Slope of shock front yields Us
Slope of pusher interface gives Up
.
Al
D2
time (ns)
shock front
Al pusher
dista
nce (µ
m)
0.0 5.01.0 2.0 3.0 4.0 6.0 7.0 8.0
0
100
200
300
x
L
Lx
=o
=
Us
Us-U
p
streak camera record
R. Lee, S. Libby, LLNL
P-P0=0UsUp
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D2 EOS data shows large differences from standard model: each data point is a shot
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2
4
4
5
5 6
7
7
0.1
1
10
Sesame 1972LM
Gas Gun
High Explosives
DAC
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cold curve (T=0)T<0
ideal gassingle shockmaximumcompression
Nova
Pre
ssu
re (
Mb
ar)
Density (/o)
Data caused, and still causes, great controversy
R. Lee, S. Libby, LLNL
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Problems common to both fields
ThermalizationHow fast can the systems thermalize?
do they actually thermalize?HOW do they thermalize?
collisions (of what) vs. interaction with (collective) fields Models & their validity range
Kinetic models for collective processesHydrodynamics
Correlations among particles in strongly coupled plasmaAffect density structure of plasmaShould give rise to correlations also in the final stateQuasi-bound states, EOS
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dense EM plasmas
usually partially ionizedatomic levels shifted by plasma screening
of interest: shock hot spot, reflectivity, radiation dynamics underlying physics: EOS, dE/dx, atomic excitations &
interaction cross sections, equilibrium & non-equil. transportdoes this sound familiar?
tools:transport calculations using detailed atomic physics info.
with some extrapolation to high T, hydrodynamics (ignoring non-equilibrium effects)molecular dynamics
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Intermediate Scattering Function
)0,(),(),( 1 kntknNtkF
)0,(),(),( 1 kntknNtkF
Consider the intermediate scattering function:
Move to a microscopic description:
N
ii
N
ii trkitkntrrtrn
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)(exp),())((),(
N
ii
N
ii trkitkntrrtrn
11
)(exp),())((),(
Collective behavior is revealed directly in terms of the Fourier transform of the intermediate scattering function: the
“dynamic structure factor”
titkFdtkS exp),(),(
titkFdtkS exp),(),(
S(k,)
M. Murillo, LANL
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Structural Quantities
rkiergrdnkS
1)(1)( 3 rkiergrdnkS
1)(1)( 3
a
eTa
Ze aY
/2
a
eTa
Ze aY
/2
3/1
2
4
3
na
Ta
ZeOCP
3/1
2
4
3
na
Ta
ZeOCP
radial distribution function
Obtained from:• molecular dynamics• Monte Carlo• integral equations (HNC)
M. Murillo, LANL
weakly polarizableneutralizing bkgd.
homogeneous, inertneutralizing backgd.
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Plasma instability in QGP → anisotropy
small deBroglie wavelength q,g point sources for g fieldsgluon fields obey Maxwell’s equationsadd initial anisotropy and you’d expect Weibel instability
moving charged particles induce B fieldsB field traps soft particles moving in A directiontrapped particle’s current reinforces trapping B fieldcan get exponential growth
(e.g. causes filamentation of beams) could also happen to gluon fields early in Au+Au collision
timescale short compared to QGP lifetimebut gluon-gluon interactions may cause instability to
saturate → drives system to isotropy & thermalization
G. Moore
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how to profit from the commonality?
survey the “other” approaches, diagnostics, theoretical tools for ideas to borrowtransport approaches, fluctuation-dissipation,
molecular dynamics, field theory are there plasma diagnostics that have unexploited
parallels?transmission, opacity measures
nuclear plasmav2 type of analysis for collective expansion
nuclear → plasmaradiation interference? reflectivity?
plasma → nuclear a workshop allowing time for real collaborative work
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High momentum or heavy quark probesHigh E(production)/short wavelength probesScreening properties via (c-anticharm) bound statesDo the heavy quarks thermalize? Lose energy?higher luminosity sufficient statistics of rare, or high pT quarkslattice QCD calculation under relevant conditions
Initial quark gluon plasma temperatureRadiated photons, e+e-detector upgrades for background rejectionlattice, hydro simulations (with relevant , coupling)
Characterize this new kind of plasmaRadiation rate, conductivity, collision frequency, equation of stateneed rare probes, including tagged jetsdetector & luminosity improvements; simulations
Consistent theoretical picture of quark gluon plasma, heavy ion collision to connect with dataneed large scale computational resources for numerical simulation
Scientific objectives for RHIC II:
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high energy density → plasma
4th state of matter (after solid, liquid and gas) a plasma is:
ionized gas which is macroscopically neutralexhibits collective effects
interactions among charges of multiple particlesspreads charge out into characteristic (Debye) length, D
multiple particles inside this lengthplasma size > D
“normal” plasmas are electromagneticquark-gluon plasma interacts via strong interaction
color forces rather than EMexchanged particles: g instead of
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Why high energy density?
Matter under extreme conditions!Fundamental physics important for astrophysicsFusion ignition, non-linear radiative hydrodynamics,
stockpile stewardship Understanding the (many-body) strong interaction
In particular: warm dense matterneither cold, condensed matter nor a plasmastrongly coupled (i.e. KE not > PE among neighbors)difficult to study analytically or numerically
Properties of interestequation of state (i.e. relationship of P to E)radiative and dynamic properties strength of materials
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Current knowledge on properties
Extract from models, constrain by dataEnergy loss <dE/dz> (GeV/fm) 7-10 0.5 in cold matter
Energy density (GeV/fm3) 14-20 >5.5 from ET data
dN(gluon)/dy ~1000 From energy loss + hydro
T (MeV) 380-400
Experimentally unknown as yet
Equilibration time0 (fm/c) 0.6 From hydro initial condition; cascade agrees
Opacity (L/mean free path) 3.5 Based on energy loss theory
Equation of state? Early degrees of freedom? Deconfinement? Cross section of resonances at high T? Conductivity?
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Taskforce members
Ronald C. Davidson, Chair, Tom Katsouleas, Vice-Chair Jonathan Arons, Matthew Baring, Chris Deeney, Louis DiMauro, Todd Ditmire, Roger Falcone, David Hammer, Wendell Hill,Barbara Jacak, Chan Joshi, Frederick Lamb, Richard Lee,B. Grant Logan, Adrian Mellissinos,David Meyerhofer, Warren Mori, Margaret Murnane, Bruce Remington, Robert Rosner, Dieter Schneider, Isaac Silvera, James Stone, Bernard Wilde, William Zajc Ronald McKnight, Secretary
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EOS data for extreme pressures are most easily accessible on the Hugoniot
Hugoniot is locus of -T points arising from an ideal strong shock
Mass Momentum Energy(xA) = o(LA)
P - Po = oUsUp
F - Fo = o(LA)(Up - 0) dQ= dE + PdV
E - Eo = Po
Up
Us
- Up
2
2L
x
o
Us
(Us - Up)
A A
o
o
L x
Up = pusher velocity
Us= shock velocity
Pusher
Sample
P
• 4 unknowns (, P, Us, Up) and 2 equations need 2 quantities for absolute measurement
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Goal: implement in situ probe of HED matter
• Employ x-ray scattering to probe the bulk: measure S(k,)
X-ray scattering
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Two Basic Models: OCP and Yukawa Plasmas
The one-component plasma (OCP) is a single species plasma with an inert, homogeneous, neutralizing background.
The Yukawa (screened-OCP) is a single species plasma with a weakly-polarizable, neutralizing background.
OCP
Yukawa
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')(2
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non-neutral plasma
dusty plasma
Court
esy
: J. J. B
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Court
esy
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