Z-Pinch Inertial Fusion Energy

1
Z-Pinch Inertial Fusion Energy


Capsule compression Z-Pinch Power
Plant Chamber Repetitive
Driver experiments on Z

LTD Technology
Joint GA/UCSD Seminar General Atomics San Diego,
CA February 17, 2004
Craig Olson and Gary Rochau Sandia National
Laboratories Albuquerque, NM 87185
Sandia is a multiprogram laboratory operated by
Sandia Corporation, a Lockheed Martin
Company,for the United States Department of
Energy under contract DE-AC04-94AL85000.
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Part 1 Z-Pinch
Inertial Fusion Energy
3

• Z-Pinch IFE Team (1000 and 6000, plus
  Universities Industry)
• C. L. Olson,a G. E. Rochau,a S. A. Slutz,a C.
  W. Morrow,a G. A. Rochau,a R. E. Olson,a A. R.
  Parker,a M. E. Cuneo,a D. L. Hanson,a G. R.
  Bennett,a T. W. L. Sanford,a G. A. Chandler,a J.
  E. Bailey,a W. A. Stygar,a J. L. Porter,a R. A.
  Vesey,a T. A. Mehlhorn,a K. W. Struve,a M. G.
  Mazarakis,a L. X. Schneider,a K. R. Prestwich,a
  G. Benevides,a T. J. Renk,a T. J. Tanaka,a M.
  A. Ulrickson,a D. H. McDaniel,a M. K. Matzen,a J.
  P. Quintenz,a P. F. Peterson,b J. S. De Groot,c
  R. R. Peterson,d,e D. Kammer,e I. Golovkin,e G.
  L. Kulcinski,e E. Mogahed,e I. Sviatoslavsky,e M.
  Sawan,e C. Gibson,f H. Tran,g P. Panchukh, R.
  Lumiai
• aSandia
  National Laboratories, Albuquerque, NM
• bUniversity of California, Berkeley, CA
• cUniversity of California, Davis, CA
• dLos Alamos National Laboratory, Los Alamos, NM
• eUniversity of Wisconsin, Madison, WI
• fGeneral Atomics, San Diego, CA
• gUniversity of New Mexico, Albuquerque, NM
• hEGG, Albuquerque, NM
• iInControl, Inc., Albuquerque, NM
• US/Russia collaboration on Z-Pinch IFE
• -

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The long-range goal of Z-Pinch IFE is to
produce an economically-attractive power plant
using high-yield z-pinch-driven targets (?3
GJ) at low rep-rate (?0.1 Hz)
Z-Pinch IFE DEMO (ZP-3, the first study) used 12
chambers, each with 3 GJ at 0.1 Hz, to produce
1000 MWe
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2038 2024 2018 2012 2008 2004 199
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Z-Pinch IFE DEMO
Z-Pinch IFE Road Map
Z-Pinch ETF (ETF Phase 2) ? ? 1B
Z-Pinch IRE ? 150M (TPC) op/year
Z-Pinch High Yield ? Z-Pinch Ignition High
Yield Facility (ETF Phase 1)
Laser indirect-drive Ignition
Z-Pinch IFE target design ? 5M /year
Z-Pinch IFE target fab., power plant technologies
? 5M /year
FI ZR Z
Z-Pinch IFE PoP ? 10M /year
Z-Pinch IFE target design ? 2M /year
Z-Pinch IFE target fab., power plant
technologies ? 2M /year
Z-Pinch IFE CE ? 400k /year (SNL LDRD )
NIF
Year Single-shot,
NNSA/DP
Repetitive for IFE, OFES/VOIFE
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Driver pulsed power

_________ Marx generator/
magnetic switching linear transformer
driver water line technology (RHEPP
technology) (LTD technology) Power feed


____ triax

coax RTL

____
Flibe/electrical coating Flibe
immiscible material


(e.
g., low activation ferritic steel) Target


__ double-pinch
dynamic hohlraum
fast ignition Chamber

_
dry-wall wetted-wall
thick-liquid wall solid/voids



Z-Pinch IFE Matrix of Possibilities
(choose one from each category)
Z-Pinch Driver

______________ Marx generator/
magnetic switching linear transformer
driver water line technology (RHEPP
technology) (LTD technology) RTL
(Recyclable Transmission Line)
_____


Flibe/electrical coating
immiscible material



(e. g., low activation
ferritic steel) Target

_
double-pinch dynamic
hohlraum fast
ignition Chamber

____


dry-wall wetted-wall
thick-liquid wall solid/voids


(e. g., Flibe foam)

Mainly science z-pinch target physics Mainly
engineering/technology z-pinch driver, RTL,
chamber
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Z-Pinch Driver
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Z-pinches offer the promise of a cost-effective
energy-rich source of x-rays for IFE
High Yield Facility
?
ZR
Z
Saturn
Proto II
Supermite
ZR will be within a factor of 2-3 in current (4-9
in energy) of a High Yield driver.
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(all are ? 60 MA)
(? 90 MA)
(? 60 MA)
(28 MA)
(18 MA)
(10 MA)
(10 MA)
(1 MA)
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Marx generator/ water line driver technology is
used on Saturn and Z/ZR
x rays 1.8 MJ
Z
Modular High Efficiency (? 15 wall-plug to
x-rays) Low cost (? 30/J) Laser-triggered
pressurized gas switches Technology is possibly
rep-rateable at 0.1 Hz with fast-cycling Marx
vacuum
water
Marx 11.4 MJ
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RHEPP II has demonstrated the high average power
capabilities of magnetic switching
420 kW, 2.7 kJ/pulse, 220 kV Blumlein PFL
Modular High Efficiency (? 50 for driver) Low
Cost Magnetic switches ( unlimited
lifetime) Already demonstrated at 120 Hz
(overkill for Z- Pinch IFE)
2.2 MeV, 25 kA, 120 Hz, 300 kW
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Linear Transformer Driver (LTD) technology is
compact and easily rep-rateable

• LTD uses parallel-charged capacitors in a
  cylindrical geometry, with close multiple
  triggered switches, to directly drive inductive
  gaps for an inductive voltage adder driver
  (Hermes III is a 20 MV inductive voltage adder
  accelerator at SNL)
• LTD requires no oil tanks or water tanks
• LTD study (as shown) would produce 10 MA in about
  1/4 the size of Saturn
• LTD pioneered in Tomsk, Russia

Modular High Efficiency ( 90 for driver) Low
Cost Switches ball-gaps in air, pressurized gas,
solid-state Easily rep-rateable for 0.1 Hz
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Key Z-Pinch Driver Issues

• Selecting best option (Marx/water line/ RHEPP/
  LTD)
• Long-lifetime switches
• Power flow configuration (from wall-plug to RTL)

All approaches are robust, industrial quality,
modular, high efficiency, pulsed power drivers
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RTL (Recyclable
Transmission Line)
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Z-pinch power plant chamber uses an RTL
(Recyclable Transmission Line) to provide the
standoff between the driver and the target
INSULATOR STACK (connects to driver)
RTL
FLIBE JETS

Z-PINCH TARGET
10-20 Torr Inert Gas
Yield and Rep-Rate few GJ every 3-10 seconds
per chamber (0.1 Hz - 0.3 Hz) Thick liquid wall
chamber only one opening (at top) for driver
nominal pressure (10-20 Torr) RTL entrance hole
is only 1 of the chamber surface area (for R
5 m, r 1 m) Flibe absorbs neutron energy,
breeds tritium, shields structural wall from
neutrons Eliminates problems of final optic,
pointing and tracking N beams, high speed target
injection Requires development of RTL
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Recyclable Transmission Line (RTL) status/issues
RTL movement (automobile assembly line
technology) RTL electrical turn-on RTL low-mass
limit and electrical conductivity RTL structural
properties/ chamber pressure RTL mass handling
RTL shrapnel formation RTL vacuum connections/
electrical connections RTL activation/ waste
stream analysis RTL shock disruption to fluid
walls RTL manufacturing/ cost RTL optimum
configuration (coax, triax, convolute,
shape, inductance, material, mass) RTL power
flow limits (physics of magnetic
insulation) Effects of post-shot EMP, plasma,
droplets, debris up the RTL Shielding of
sensitive accelerator/power flow feed parts
...
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RTL replacement requires only modest acceleration
for IFE
L 0.5 a t2 , or a 1/t2
Acceleration is 104 less than for IFE target
injection for ions or lasers
104 g
1 g
10 g
0.1 g
100 g
1,000 g
rifle bullet
0.01 g
IFE RTL replacement for rep-rated z pinches
Prometheus-L
OSIRIS, SOMBRERO, Prometheus-H
Car (0 - 60 mph in 10 s)
IFE target injection for ions and lasers
( 10 Hz)
( 0.1 Hz)
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RTL experiments on Saturn at the 10 MA level show
uniform electrical turn-on for all materials
tested
RTL electrical turn-on
Height 30 cm Diameter 8 cm Gap 3
mm
The diameter of the RTL was chosen to provide
current density comparable to a reactor system
Power flow within Saturn limits the load
inductance to less than 5 nH. Only nontoxic
materials were tested, e. g. tin, aluminum, and
stainless steel Current monitors placed at the
top, middle, and bottom of the RTL showed no loss
of current for any material
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RTL low-mass
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RTL FINITE ELEMENT MODEL constructed in ANSYS to
perform structural analysis
RTL Structural
R 50 cm r 5 cm L 200 cm 25 mil steel disc
10 cm lip
Fusion Technology Institute University of
Wisconsin, Madison
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PRELIMINARY BUCKLING ANALYSIS of steel RTL
RTL Structural
78 Torr RTL buckles at 1.52 psi 78
Torr as shown 20 Torr no effect
(safe operating point)
Fusion Technology Institute University of
Wisconsin, Madison
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RTL mass handling
One day storage supply of RTLs (at 50 kg each)
has a mass comparable to one days waste from a
coal plant
Z-Pinch IFE
Coal-fired Power Plant
(1 GWe Power Plant)
San Juan Generating Station (1.6 GWe)

(Four Corners area, NM)

Burns 7 million tons coal/year
Waste
1.5 million tons/year RTLs one-day storage
Coal 30-day storage supply
supply at site is 5,000 tons
at site is 600,000 tons


Burns 20,000 tons/day


Waste 5,000 tons/day
(flyash and
gypsum, that must be
disposed
of in the adjacent coal mine) RTLs are
recycled with minimum waste
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Capability to model thick liquid wall disruption
by the target explosion may be studied using
chemical detonations with liquid flows
TargetRTL interaction with liquid wall
Impulse-affected region- note divot
New liquid interface
25 cm
10 msec
- 6 msec
2 msec
18 msec
26 msec
.
4
0
I 45 Pa sec
3
0
Surface position (mm)
2
0
1
0
0
2
4
6
8
1
0
1
2
1
4
UCB
T
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e

(
m
s
)
A
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y
t
i
c
96-jet nozzle assembly in operation
S
h
o
t

D
a
t
a
Incompressible theory accurately predicts shock
propagation
UC Berkeley
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RTL Activation/Waste Stream
Activation/Waste Stream Analysis

• Recycling is a must requirement for
  transmission lines to minimize heavy metal
  throughput and enhance economics
• A few-day RTL inventory seems reasonable for
  proposed recycling approach (to handle
  manufacture time, cooling time, and backup
  inventory)
• Activated RTL Fe-based materials should be
  handled remotely (no hands on) and satisfy design
  requirements -recycling dose ? 3000 Sv/h
  
  -low level Class C waste (WDR ? 1)
• Online removal of transmutation products during
  recycling process helps meets requirements with
  margin

Fusion Technology Institute University of
Wisconsin, Madison
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Research/development of RTLs is about to begin as
part of a Z-Pinch IFE program

• Power flow to the RTL
• Power flow limits
• Optimal feed (coax, triax, convolute,)
• RTL
• RTL shape, inductance, material, mass
• RTL electrical properties, structural properties
• RTL manufacturing/recycling/cost
• RTL chamber/interface issues
• RTL vacuum connections, electrical connections
• Effects of post-shot EMP, plasma, droplets,
  debris up the RTL
• Shielding of sensitive accelerator/power flow
  feed parts
• RTL demonstration experiments
• Design and build PoP scale RTLs
• Test structurally for chamber pressure and
  electrically at 1 MA
• Design/cost/fabricate/schedule an RTL
  demonstration on Z

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Targets
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Z-pinch-driven-hohlraums have similar topology to
laser-driven-hohlraums, but larger scale-size
Double ended hohlraum
35 mm
Dynamic hohlraum
6 mm
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The baseline DEH capsule yields 380 MJ withan
ignition margin similar to a NIF capsule
Capsule Performance Parameters
Peak drive temperature In-flight aspect
ratio Implosion velocity Convergence ratio Total
RT growth factor Peak density Total rr Driver
energy Absorbed energy Yield Burnup fraction
223 eV 37 2.9 x 107 cm/s 36 420 750 g/cm3 3.15
g/cm2 16 MJ 1.12 MJ 380 MJ 31
J.H. Hammer, et al., Phys Plasmas 6, 2129
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The initial dynamic hohlraum high yield
integrated target design produces a 527 MJ yield
at 54 MA
Capsule Performance Parameters
solid Be
Peak drive temperature In-flight aspect
ratio Implosion velocity Convergence ratio DT KE
_at_ ignition Peak density Total rr Driver
energy Absorbed energy Yield Burnup fraction
350 eV 48 3.3 x 107 cm/s 27 50 444 g/cm3 2.14
g/cm2 12 MJ 2.3 MJ 527 MJ 34
Be3 Cu
solid DT
DT gas (0.5 mg/cm3)
0.225 cm radius
0.249 cm radius
0.253 cm radius
0.275 cm radius
J.S. Lash et al., Inertial Fusion Sciences Apps
99, p583
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Code calculations and analytic scaling predict
z-pinch driver requirements for IFE DEMO
Double-Pinch Hohlraum
Dynamic Hohlraum
current /x-rays Eabs / yield
current /x-rays Eabs / yield
54 95 MA 12-37 MJ 2.4 7.2 MJ 530 4400 MJ
2 x 62-68 MA 2 x (16-19) MJ 1.3 2.6 MJ 400
4000 MJ
Based on these results, an IFE target for DEMO
will require double-pinch hohlraum
dynamic hohlraum 36 MJ of x-rays (2x66MA) 30
MJ of x-rays (86 MA)
3000 MJ
yield 3000 MJ yield
(G 83)
(G 100)
J. Hammer, M. Tabak, R. Vesey, S. Slutz, J. De
Groot
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Chambers/Power Plant
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Thick liquid walls essentially alleviate the
first wall problem, and can lead to
a faster development path
33
Z-Pinch Power PlantProposed Cartridge Cycle
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Steel Recycle Uses Standard Industrial Process
Equipment (augmented for remote operation)
Development required to augment equipment for
remote operation
Hydraulic Robotics not electronic
35
Steel RTL Unit Cost/Risk Distribution
RTL remanufacturing/cost
Allowed RTL budget is a few for 3 GJ yields
above results show 90 confidence level at 3.58
with existing processes
36
Z-IFE DEMO produces 1000 MWe
DEMO parameters yield/pulse
3 GJ driver
x-rays/pulse (86 MA) 30 MJ
energy recovery factor
80 thermal recovery/pulse
2.4 GJ time between pulses/chamber
3 seconds thermal power/unit
0.8 GWt thermal conversion
efficiency 45 electrical
output/unit 0.36 GWe
number of units
3 total plant power output
1.0 GWe Major cost elements LTD z-pinch
drivers (3) 900 M RTL
factory
500 M Target factory
350 M Balance of Plant
900 M
Total Cost 2.65
G
ZP-3 (the first study) used 12 chambers, each
with 3 GJ at 0.1 Hz
Z-Pinch power plant studies G. Rochau, et al.
ZP-3
J. De Groot, et al. Z-Pinch Fast
Ignition Power Plant
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Part 2 Proposed Allocation
of FY04 Congressional Initiative Funding of 4M
for Z-Pinch IFE
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Key Scientific Question for Z-Pinch IFE
Given that the key target physics issues are
being addressed in the NNSA DP ICF program, the
key scientific question for z-pinch IFE is Can
a repetitive pulsed power driver be connected
directly to a fusion target with a recyclable
transmission line to make an attractive inertial
fusion energy power plant?
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Primary Issues for Z-Pinch IFE
For this Initiative, research is proposed to
address the following primary issues for z-pinch
IFE 1. How feasible is the RTL concept? 2.
What repetitive pulsed power drive technology
could be used for z-pinch IFE? 3. Can the shock
from the high-yield target (3 GJ) be effectively
mitigated to protect the chamber structural
wall? 4. Can the full RTL cycle (fire
RTL/z-pinch, remove RTL remnant, insert new
RTL/z-pinch) be demonstrated on a small (PoP)
scale? 5. What is the optimum high-yield target
for 3 GJ, and what are the power flow
requirements for this target? 6. What is the
optimum power plant scenario for z-pinch IFE? 7.
What is the path forward for z-pinch IFE?
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Research Plan and Proposed Allocations
The Research Plan consists of seven tasks that
address the seven primary issues. It is proposed
to allocate the 4M between the seven tasks as
follows Task 1. RTL
1,100,000 Task 2. Repetitive
Driver 900,000 Task 3.
Shock Mitigation
400,000 Task 4. Full RTL cycle (PoP)
200,000 Task 5. IFE targets
400,000 Task 6. Power
Plant Technologies 700,000 Task 7.
Assessment Path Forward
100,000 contingency
200,000

_________ Total
4,000,000
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Summary of Collaborating Institutions
Collaborating National Laboratories LLNL,
LBNL, LANL, NRL, INEEL Collaborating
Universities UCB, U.Wisc., UCD, UCLA,
Georgia-Tech, U. Missouri, Texas
Tech, UNM, UNR, Cornell,
UCSD Collaborating Industry PSI, GA,
Luxel, MRC, FPA Collaborating Institutions in
Russia Kurchatov (Moscow), Institute
for High Current Electronics (Tomsk)
Institute for Theoretical and Experimental
Physics (Moscow) Potential Collaborator
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Part
3 Status of home for Z-Pinch IFE in DOE
43
Some dominating concerns from Washington,
DC ITER Science HEDP no urgency to develop
fusion energy technologies (wait for burning
plasma demonstrations - ITER, NIF)
44
Some of the important offices that influence
funding of fusion energy
DOE
OMB
OSTP Spencer Abraham NNSA
John
Marberger Bob
Card
Joel
Parriott Patrick Looney SC
NE EERE DP Ray Orbach
Ev Beckner OFES
Anne Davies Dave
Crandall John Willis
Chris Keane Francis Thio
Ralph Schneider OFES charter is science
DP charter is NOT energy

45
SNL Z-Pinch contributions to
HAPL Laser dry-wall materials testing for
x-rays on Z and ions on RHEPP HIF
Collaborations between HIF-VNL and SNL
(P4 target symmetry on Z, thick liquid walls,
LTD,..) Workshop at SNL on February
26-27, 2004 HEDP Every shot on Z is HEDP
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How Z-Pinch IFE will help advance ICF and HEDP in
support of NNSAs Mission
The development of RTLs, LTD repetitive
pulsed power technology, and thick liquid walls
should advance several areas outside of IFE. The
use of RTLs has the potential to enable a higher
shot rate, and at lower cost, on Z/ZR for ICF and
HEDP research. The use of LTD technology should
enable more compact, and repetitive, pulsed power
accelerators. The use of thick-liquid walls,
even on a single-shot basis, is envisioned to
minimize the activation issue for a high-yield
facility. In fact, the combination of RTLs, LTD
repetitive pulsed power, and thick liquid walls
should enable a more attractive z-pinch
high-yield facility (that could later be
converted to a repetitive driver for IFE).
From the science viewpoint, several key
physics issues for z-pinch IFE are in the power
flow in the RTL. The physics of such
magnetically-insulated transmission lines
involves formation of plasmas on the electrode
surfaces, the initial launching of an electron
flow that becomes trapped in ExB flow, symmetry
of the power flow during radial convergence to
the target, and the potential for plasmas to
cross the small electrode gap and short out the
power flow. Z uses magnetically-insulated
transmission lines, and works extremely well at
the 20 MA level. However, as higher currents are
required on the path to IFE, the physics of power
flow in the RTL must continually be re-examined.
This research, as part of IFE, will directly
enable higher current drivers for ICF to be
realized. Fusion energy, in this case
z-pinch IFE, is also very useful in attracting
new talent to the NNSA DP laboratories. In fact,
many people are drawn to the laboratories for
fusion energy, and then later become important
contributors to the NNSA DP weapons physics
missions.