1 4/22/2002 aries1 fusion technology institute 4/22/2002 dynamics of liquid wall chambers r.r....

4/22/2002 14/22/2002 ARIES 1Fusion Technology Institute

Dynamics of Liquid Wall Chambers

R.R. Peterson, I.E. Golovkin, and D.A. Haynes

University of Wisconsin

ARIES MeetingMadison, WI

April 22 and 23, 2002


Why Are Liquid Walls Considered When Gas-Protected Dry-Walls Can Work for Direct-Drive Laser Fusion and Are Simpler?

Gas-Protected Dry-Wall Liquid-Wall

Driver Beam Transport Laser or HIB with Channel Transport

Laser, HIB or Pulsed-Power with Vacuum Transport

Target Type Direct-Drive Laser (many symmetric beams)

Indirect Drive Laser or HIB

Total Target Yield per Wall Area per Shot

< 75 J/cm2 Much Higher

Limit on Rep-Rate Gas Cooling Condensation of Vapor and Migration of Aerosols

First Wall Environment Neutron and Ion Damage, High Thermal Gradients

Benign

Number of Ports > 60 1 or 2


Liquid Walls Are Intended To Vaporize While Dry Walls Must Not

•Liquid walls may be rapidly replaceable, either as a surface film or as free-standing jets.

•Liquid walls are not subject to neutron damage, sputtering, and blistering, which are all important issues for dry walls.

•Thermal damage and erosion are serious issues for dry-walls (< 1 mono-layer of erosion allowed per shot) but are not an issue for liquid walls.

•Target remnants can be captured by liquid.

•Condensation of vapor and removable of aerosols and splashed chunks limits rep-rate.


Liquid Wall Phenomenology Drives IFE Chamber Design

•Chamber gas/vapor density at beam transport (HIB: channel, self-pinched or ballistic; Laser) has limits.

•Gas in chamber at time of target explosion can partially protect liquid from vaporization (LIBRA).

•Vaporization induces strong shocks in the liquid that impart large impulses and high pressures to structures

•Blow-off vapor exhibits complex behavior, including nucleate condensation into aerosols, absorption of late x-rays and ions from the target, and re-radiation of energy to the liquid surface.

•Condensation of vapor limits rep-rate and is enhanced by large surface area (HYLIFE, HIBALL, …) and large thermal velocity of vapor atoms (Li versus Pb).

•Aerosol dynamics will also limit rep-rate.


ZP3 Concept Extends the Recent Exciting Results of Pulsed-Power Driven ICF Physics to a Power Plant

Z-like Insulator Stack and MILT

Wire-Array Hohlraum and IFE Capsule

Replaceable Inner MILT and Power Flow


ZP3, a Z-Pinch Power Plantis a New Example of Thick Liquid Wall Protection

INSULATORSTACK

PLUNGER

FLIBEPUMP

FLIBEJETS

CRUCIBLE

POOL AND DEBRISMOMENTUMDIFFUSER

LARGE PARTICULATECOLLECTIONS

SYSTEM TO HEAT EXCHANGER

LIQUID METAL/MOLTEN SALT

POOL

REPLACEABLEENERGY ABSORBING

SHELL

TUNGSTENHEMISPHERICAL

SHELL FOR ENERGYREFLECTION

LOAD

PULSED POWER DRIVERRTL

MOLTEN FLIBE

INSULATORSTACK

PLUNGER

FLIBEPUMP

FLIBEJETS

CRUCIBLE

POOL AND DEBRISMOMENTUMDIFFUSER

LARGE PARTICULATECOLLECTIONS

SYSTEM TO HEAT EXCHANGER

LIQUID METAL/MOLTEN SALT

POOL

REPLACEABLEENERGY ABSORBING

SHELL

TUNGSTENHEMISPHERICAL

SHELL FOR ENERGYREFLECTION

LOAD

PULSED POWER DRIVERRTL

MOLTEN FLIBE


Target

1-D BUCKY Calculations for ZP3 Are Performed For Two Cases: With and Without Liquid Protection

•1-D spherical geometry•Preliminary: Li instead of Flibe (we now have Flibe opacity)•~900 MJ in x-rays•~100 MJ in Pb ions•Chamber interior temperature – 600oC

¼ atmHe

¼ atmHe

Li

Steel

50cm

50cm

200cm

250cm

Down into Pool

Without liquid


BUCKY Target Simulations of X-1 Output Were Scaled From 400 MJ to 4 GJ

Time (ns)

Po

sitio

n(c

m)

120 130 140 1500

0.1

0.2

0.3

0.4

0.5

0.6

0.7

X-1 Capsule

X-1.28

Implosion without hohlraum; radiation drive

Time (ns)P

osi

tion

(cm

)156 157 158 159 160 1610

0.1

0.2

0.3

0.4

0.5

0.6

0.7

X-1 Capsule and HohLraum

X-1.27

Final implosion and burn with hohlraum; no drive

BeO

DT

Be98O2

BeO

DT

Au


BUCKY Target Simulation of X-1 (400 MJ) Output Shows Two Major Pulses: Direct Emission

from Capsule and From Capsule Kinetic Energy Converted to Radiation by Hohlraum

Time (ns)

Ra

dia

ted

Po

we

r(P

W/c

m2)

156 157 158 159 160 1610

10

20

30

40

50

X-1 Capsule and Hohlraum

X-1.27

Spectrum is about a 1 keV BB

•If the Hohlraum is cylindrical, the 2nd pulse will be more spread-out.•Emissions may be anisotropic (NIF target is).


Time, s

Va

po

rize

dm

ass

,g

5E-09 1E-080

1000

2000

3000

4000

5000

Frame 001 24 Jul 2001 Frame 001 24 Jul 2001

Thickness of vaporized material

Time, s

Vapo

rize

dm

ass

,g

5E-09 1E-08 1.5E-08

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

Frame 001 25 Jul 2001 Frame 001 25 Jul 2001

~ 3.5 mm ~ 0.02 mm

Li at 50 cm Steel at 250 cm

X-rays vaporize material from the surface

Even though Steel experiences much less vaporization depth, the total mass vaporized is greater.

Non-neutronic fluence

38,000 J/cm2 1,500 J/cm2


Time, s

rad

ius,

cm

0 5E-06 1E-05 1.5E-05 2E-0540

42

44

46

48

50

52

54

56

Frame 001 25 Jul 2001 |Frame 001 25 Jul 2001 |

Time, s

rad

ius,

cm

0 5E-06 1E-05 1.5E-05 2E-05

249.8

250

250.2

250.4

250.6

250.8

251

Frame 001 25 Jul 2001 |Frame 001 25 Jul 2001 |Li Layer 50 cm Steel at 250 cm

Recoil Pressure From Intense Vaporization Drives Shock Wave Propagation in the Materials

Vaporization driven shock structure in Lithium is initially complex but it smoothes as it moves into the fluid.


Pressure temporal profiles at different depths (Li)

Time, ns

Pre

ssure

,J/c

m3

0 10000 20000 30000

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

12000

1cm2cm5cm10cm

Frame 001 25 Jul 2001 | | |Frame 001 25 Jul 2001 | | |

Pressure Within Lithium Shows Multiple Shocks Decaying at Increasing Depth

•Importance of dissipation.

•At 1 cm into Li, initial shock is 115 kbar in < 1 s.

•10 cm into Li, shock pressure is still 45 kbar and is spread over 7 s.

•Eventually shocks coalesce.


Thickness (cm)

Pressure (kbar)

Impulse (Pa-s)

Time (s)

1 384 4175 0.77

2 185 25973 5.24

5 221 43532 10.36

10 147 43448 20.00

Maximum pressure and corresponding impulse at the back surface for different thickness of Li layer

Impulse is Conserved As Shock Moves into Lithium


Analysis of Liquid Wall Chamber Concepts Needs Validation

Validation of BUCKY has been in progress for about 15 years.•Fireball experiments on Pharos-II.•X-ray vaporization experiments on Nova, Helen, Saturn, and Z.•Ion vaporization experiments on RHEPP.

Additional validation is needed.•Wall condensation•Nucleate condensation•X-ray driven shock impulse measurements.•Fireball radiation (what can we learn from Tokamak disruption experiments?)•Target output spectra


Proposed new role for BUCKY

• Extend BUCKY to community code status

• Restricted access to BUCKY collaborators, who are expected to help with validation and/or new models

• Extend documentation• Example input files and data files for many types

of calculations• Web interface to conveniently submit jobs and

retrieve results• BUCKY application server at UW


BUCKY Has Been Under Development for About 3 Decades

1975 1980 1985 1990 1995 2000

PHD-IV•TN burn•Gray Radiation Diffusion•1-D Lagrangian Hydro•Te Ti

PHD-IV

Target Implosion, Burn, Explosion

FIRE•Start with PHD-IV•Remove TN burn• Multi-group Diffusion•X-ray and ion energy sources•Te = Ti

FIRE

Gas filled target chambers

CONRAD•Start with FIRE•Vaporization and Condensation by Chamber Wall

CONRAD

•Vaporizing IFE chamber walls•Tokamak disruption divertor vaporization

BUCKY•Combine PHD-IV and CONRAD•TN burn• Multi-group Diffusion•Laser deposition•Te Ti•Time-dependent CRE radiation transport

BUCKY

•NIF Capsules•NIF chamber wall experiments•NRL laser targets•Z experiments•ARIES target chamber


EOS and Opacity Codes for BUCKY have Also been written over a long time

1975 1980 1985 1990 1995 2000

MIXERG•Gray and Multi-group Opacities for FIRE•Rosseland and Planck•Semi-Classical absorption coefficients•Tabulated ionization energies•Saha or Coronal Ionization•Self-consistent ionization for mixtures•EOS: ideal gas + ionization and excitations

MIXERG

IONMIX•MIXERG +•Non-LTE Ionization•Multi-group•Rosseland and Planck absorption and emission

IONMIX

EOSOPA•Hartree-Fock (Cowan) atomic structure•LS coupling•UTA or DCA/LTE or CRE for Z ( 18)•UTA/LTE for Z (18)•Creates data for CRE in BUCKY•Pressure ionization•Muffin-Tin EOS

EOSOPA

RSSOPA•Relativistic (Dirac eqn.)•JJ coupling•SOSH UTA’s

RSSOPA

JATBASE•JAVA interface for EOSOPA•User friendly

JATBASE

1 4/22/2002 aries1 fusion technology institute 4/22/2002 dynamics of liquid wall chambers r.r....

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