Transcript Tuxedo - University of California, San Diego

Summary of Research in the
Advanced Energy Technology Group
at UC San Diego
Farrokh Najmabadi and Mark Tillack
March 2004
http://aries.ucsd.edu
Our Research Staff and Students
Sophia Chen
graduate student
Electrical & Computer Engineering
Brian Christensen
graduate student
Mechanical & Aerospace Engineering
Kevin Cockrell
undergraduate
Electrical & Computer Engineering
Zoran Dragojlovic
project scientist
Electrical & Computer Engineering
Andres Gaeris
project scientist
Electrical & Computer Engineering
S. S. Harilal
project scientist
Electrical & Computer Engineering
Tak Kuen Mau
research scientist
Electrical & Computer Engineering
Farrokh Najmabadi
professor
Electrical & Computer Engineering
Beau O’Shay
graduate student
Electrical & Computer Engineering
John Pulsifer
engineer
Center for Energy Research
René Raffray
research scientist
Mechanical & Aerospace Engineering
Kevin Sequoia
graduate student
Mechanical & Aerospace Engineering
Dai Kai Sze
research scientist
CER/MAE
Mark Tillack
research scientist
Mechanical & Aerospace Engineering
Phyllis Voigts
administrative specialist
Center for Energy Research
Xueren Wang
engineer
Center for Energy Research
Summary of Research Activities
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ARIES Fusion Concept Studies
High Average Power Laser Program
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final optics
chamber clearing
dry-wall armor thermomechanics
cryogenic target survival
Inertial Fusion Energy Chamber Physics
– magnetic diversion of ablation plumes
– phase change physics
• Laser-Matter Interactions
– laser ablation plume dynamics and cluster formation
– laser plasma EUV light source
•
Thermal Sciences
1. ARIES Fusion Concept Studies
The ARIES Team has examined several
magnetic and inertial fusion power plant
concepts during the past 15 years
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TITAN reversed-field pinch (1988)
ARIES-I first-stability tokamak (1990)
ARIES-III D-3He-fueled tokamak (1991)
ARIES-II and -IV second-stability tokamaks (1992)
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Pulsar pulsed-plasma tokamak (1993)
SPPS stellarator (1994)
Starlite study (1995) (goals & technical requirements for power plants & Demo)
ARIES-RS reversed-shear tokamak (1996)
ARIES-ST spherical tokamak (1999)
ARIES-AT advanced tokamak (2001)
ARIES-IFE IFE chamber studies (2003)
ARIES-CS compact stellarator (ongoing)
Concept studies incorporate customer requirements and the existing database to assess
concepts, innovate, and guide the base program
Customer Input
Mission
and Goals
Present Data Base
Concept Studies
Design Options
R&D Program
Evaluation Based on
Customer Attributes
Attractiveness
Redesign
Characterization
of Critical Issues
Feasibility
Assessment
R &D Needs,
Development Plan
ARIES integrated IFE chamber analysis
and assessment research was a 3-year
exploration study, recently completed
Objectives:
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Analyze & assess integrated and self-consistent IFE chamber concepts
Understand trade-offs and identify design windows for promising
concepts. The research was not aimed at developing a point design.
Approach:
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Six classes of realistic target were identified. Advanced target designs
from NRL (laser-driven direct drive) and LLNL (Heavy-ion-driven
indirect-drive) were used as references.
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To make progress, the activity was divided based on 3 chamber classes:
• Dry wall chambers;
• Solid wall chambers protected with a “sacrificial zone” (such as liquid
films);
• Thick liquid walls.
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These classes of chambers were researched in series with the entire team
focusing on each.
History of the UCSD IFE program
OFES proposal
1997
1998
lab YAG
1999
LLNL-funded studies
of chamber simulation
experiments
vacuum excimer
Staff
system laser
ramp-up
2000
2001
2002
OFES grant on chamber
physics, modified to
address final optics
dry walls
new lab
2003
2004
OFES grant on chamber
physics (terminated)
liquid walls
ARIES-IFE
DP HAPL programs
GA target engineering
2. High Average Power Laser Program
Our IFE research is focused on the key issues
for IFE chambers and chamber interfaces
• Final optics that survive
the environment
• Understanding of residual
chamber medium and
propagation of targets
and beams through it
– Chamber dynamic response,
chamber clearing
– Beam & target interactions
• Chamber walls that
survive or are renewable
• Cryogenic targets that
survive injection
Prometheus-L Reactor Building
We are developing damage-resistant final optics
based on grazing-incidence metal mirrors
Objectives:
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Measure laser-induced damage threshold
and demonstrate long-term operation of a
grazing incidence metal mirror at
laser fluence of ~5 J/cm2 normal to the
beam.
Determine limits due to contamination &
other target threats.
Determine effects of damage on beam
quality.
viewing port
beam diagnostics
dump
cube
1/2 waveplate
specimen
mount
cube
dump
The SPARTAN chamber dynamics and clearing
code was developed for studies of the post-blast
chamber environment
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2-D Transient Compressible Navier-Stokes Equations.
Second order Godunov method, for capturing strong shocks.
Diffusive terms (conductivity, viscosity) depend on local state
variables.
Adaptive Mesh Refinement for uniform accuracy throughout the
fluid domain.
Arbitrary boundary resolved with Embedded Boundary method.
Cyclic thermomechanical behavior of drywall chamber armor is under investigation
A fast (nanosecond) optical
thermometer was developed to
assist the project with time-resolved
surface response measurements
Temperature is calculated from
measurement of radiated energy at
two wavelengths:
 1
 1
1 
1 
c 2   
c 2   
 1  2 
 1  2 
T 
 
    5 L       5 C V  
2
2
  ln  2  2 2  
ln  
  1  L1     1  C1 V1  
Survival of cryogenic direct-drive targets in hot,
turbulent chambers is a challenging problem
Thermal, mechanical and phase change studies were performed
on cryogenic DT targets subjected to chamber heating
Local
Vapor
Bubble
8.00E-06
Rigid, tv_o = 1e-6 m
Vapor Thickness (m)
7.00E-06
t = 0.015 s
Rigid, tv_o = 3e-6 m
6.00E-06
ro
Tinit = 18 K
Bending, tv_o = 1e-6 m, ro = 5e-6 m
tv,o
Bending, tv_o = 3e-6 m, ro= 5e-6m
5.00E-06
DT
Vapor
Core
Bending, tv_o = 1e-6 m, ro = 7e-6 m
4.00E-06
3.00E-06
2.00E-06
1.00E-06
Rigid DT
Solid
+
0.00E+00
0
1
2
3
4
5
6
7
8
9
Plastic
Shell
10
2
Heat Flux (W/cm )
Pre-existing vapor bubbles could close if initial bubble is
below a critical size and the heat flux above a critical value
3. Inertial Fusion Energy Chamber Physics
Magnetic diversion of expanding laser
plasma is being studied as a possible
means to mitigate target debris
Phase change physics is important for understanding the generation of impulse and behavior
of aerosols in liquid-protected IFE chambers
• Homogeneous nucleation and
growth from the vapor phase
– Supersaturated vapor
– Ion-seeded vapor
– Impurity-seeded vapor
Spinodal decomposition of Si (Craciun)
• Phase decomposition from
the liquid phase
– Thermally driven phase
explosion
– Pressure driven fracture
• Hydrodynamic droplet
formation (flow conditioning)
4. Laser-Matter Interactions
Laser ablation plume dynamics is extremely
complex, involving laser interactions, phase
change, gasdynamics, atomic and plasma physics
0.01 Torr
0.1 Torr
1 Torr
10 Torr
100 Torr
Ionization was shown to play a dominant role in
nanocluster formation in laser ablation plumes
Polyimide laser ink-jet
printer head (courtesy of HP)
5x109 W/cm2
We recently began a program of research on
next-generation semiconductor lithography
based on laser-plasma EUV emission
Achieving higher efficiency and
lower contamination are key
issues for EUV light sources
5. Thermal Sciences
Studies of heat transfer enhancement techniques
are equally important in high heat flux
applications (like fusion) and energy efficiency
• Heat transfer in porous and granular media
– Energy recovery ventilator
– High heat flux devices
Coaxial heat exchanger
Hot Stream (packed w ith porous media)
Di
Conductive Wall (Alloy 122 Copper Tubing)
t
Cold Stream (packed w ith porous media)
Insulated Wall (3 in PVC pipe)
di
di = 1.936 inches
t = 0.032 inches
Di = 3.068 inches
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UCSD Laser Plasma and
LaserMatter Interactions Laboratory