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DAH, UW-FTI ARIES-IFE, April 2002, 1
Results from parametric studies of thin liquid wall IFE chambers
D. A. Haynes, Jr.Fusion Technology Institute
University of Wisconsin, Madison
600C, 4.5m radius Pb liquid protected chamber
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
1.E-08 1.E-07 1.E-06 1.E-05 1.E-04
Time (s)
Vap
oriz
ed m
ass
(g)
10 mTorr
1000mTorr
Time (s)
Ra
diu
s(c
m)
10-7 10-6 10-5 10-40
50
100
150
200
250
300
350
400
450
BUCKY Vaporization simulation: HIB targetin a 4.5m radius, 1mm Pb protected chamber, Tc=600C
DAH, UW-FTI ARIES-IFE, April 2002, 2
Summary/Outline
We present results from a set of BUCKY simulations of the response of a thin liquid wall chamber to the threat spectrum of the C/C HIB target. Parameters considered were wall material (Pb or FLiBE), vapor composition (Xe or vapor
from the liquid) and vapor pressure. All variations considered lead to acceptable chambers from the point of view of ion deposition, vaporization thickness and
condensation rates, though these simulations do not include the effects of splashing or aerosolization.
•Wall material (Pb or FLiBe)
•Vapor pressure (10mTorr or 1000mTorr)
•Vapor composition (Xe or wall material)
•Conclusions and future work
•Old business: dry wall strawman results
DAH, UW-FTI ARIES-IFE, April 2002, 3
Wetted-Wall Chamber Physics Critical Issues Involve Target Output, and First Wall Response
Target OutputSimulations
(BUCKY, etc) Target Disassembly
Energy Partition
Target OutputSimulations
(BUCKY, etc) Target Disassembly
Energy Partition
Liquid DynamicsSimulations(BUCKY)
X-ray DepositionVaporizationSelf-Shielding
Shocks in Liquid
Liquid DynamicsSimulations(BUCKY)
X-ray DepositionVaporizationSelf-Shielding
Shocks in Liquid
Chamber Recovery Simulations
(1-D: BUCKY,2, 3-D TSUNAMI, ?)
Re-condensation,Substrate Survival
Chamber Recovery Simulations
(1-D: BUCKY,2, 3-D TSUNAMI, ?)
Re-condensation,Substrate Survival
X-rays,Ion Debris,Neutrons
Vapor MassImpulse
Rep-Rate
Target Design
Wall Design
Low T,Hi
Opacity
LiquidProperties
BeamTransportCriteria
Vapor Opacity
DAH, UW-FTI ARIES-IFE, April 2002, 4
Target output x-ray spectra
0.0
0.2
0.4
0.6
0.8
1.0
0.01 0.1 1 10 100
Energy (keV)
Sp
ect
ra (
pe
ak
no
rma
lize
d)
HIB (LASNEX)
2.14MJ
115MJ
This talk concentrates on the effects of the threat from the closely coupled HIB target. The threat is predominantly from the soft x-rays produced by the interaction of capsule
output and the massive hohlraum
HIB (~400MJ) n
fusion products
x-rays
D
T
p
He
C
Au
Be
Fe
Br
Gd
Though this target is not currently being emphasized by the HIB target community, its threat spectrum should be grossly similar to the more likely contenders. As this target is the only one for which we have detailed threat spectra, we use it a representative.
DAH, UW-FTI ARIES-IFE, April 2002, 5
We have generated relevant FLiBE opacity and equation of state
FLiBe Rosseland Group Opacities, kT=1eV
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E-01 1.E+01 1.E+03
Photon Energy (eV)
Opa
city
(cm
^2/g
)
Ion Density = 2.5e17/cm 3̂
Average charge state, kT=1eV
0.00.10.20.30.40.50.60.70.80.91.0
1.E+16 1.E+18 1.E+20 1.E+22
Ion Density (/cc)
Av
e. C
ha
rge
Sta
te
Calculations performed using DTAOPA, a detailed transition
accounting, NLTE version of EOSOPA
DAH, UW-FTI ARIES-IFE, April 2002, 6
FLiBe is considerably more transparent to the target x-rays than is Pb. This leads to more volumetric heating of the liquid, and less shielding by the chamber vapor
and the superheated vapor.
Starting conditions: 1000mTorr Vapor at 600C450cm radius chamber
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
1.00E-08 1.00E-07 1.00E-06 1.00E-05 1.00E-04
Time (s)
Vap
ori
zed
mas
s (g
)
Pb
FLiBe
As of 0.1ms after implosion:
•X-ray energy absorbed in vapor:
•FLiBe: 36MJ
•Pb: 114MJ
•Energy re-radiated to the wall:
•FLiBe:16MJ
•Pb: 60MJ
DAH, UW-FTI ARIES-IFE, April 2002, 7
A hybrid design using both a chamber gas chosen for beam transport and a thin liquid wall chosen to protect the first wall is conceivable: 1000mTorr Xe
As of 0.1ms after implosion:
•X-ray energy absorbed in vapor:
•FLiBe wall: 78MJ
•Pb wall:111MJ
(Blow-off is treated as vapor for this purpose. Note that the Pb created early in the pulse better shields the wall from the end of the pulse.)
•Energy re-radiated to the wall:
•FLiBe wall: 25MJ
•Pb wall: 31MJ
Xe chamber gas, 600C, 4.5m radius chamber
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
1.E-08 1.E-07 1.E-06 1.E-05 1.E-04
Time (s)
Va
po
rize
d m
as
s (
g)
Pb Wall
FLiBeWall
DAH, UW-FTI ARIES-IFE, April 2002, 8
Different driver transport beam transport methods require different pressure of chamber gas. Last meeting we looked at 1mTorr. Here, we look at 10mTorr and 1000mTorr.
•The lower Pb chamber pressure actually results in less vaporized mass at the end of 0.1ms. This is due to the effect of soft, re-radiated energy due to ions and x-rays absorbed in the chamber gas.
•Re-radiated energy:
•10mTorr:36MJ
•1000mTorr 60MJ
600C, 4.5m radius Pb liquid protected chamber
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
1.E-08 1.E-07 1.E-06 1.E-05 1.E-04
Time (s)
Vap
oriz
ed m
ass
(g)
10 mTorr
1000mTorr
DAH, UW-FTI ARIES-IFE, April 2002, 9
BUCKY does not include the effects of aerosol formation nor splashing. We have handed off early time, post flash chamber conditions to Phil
Sharpe, who will report on his analysis of aerosol issues later this meeting.
Plan of attack from last meeting:
•“Homogenize” chamber, converting bulk kinetic energy into thermal energy.
•Start condensation run from these conditions.
•Geometry dependent uncertainty: how long does it take to homogenize, and will there be any x-ray pulse produced by stagnation on axis?
Post-homogenization condensation1 mm Pb liquid wall, HIB target , 21.5kg homogenized vaporized
mass
0.0001
0.0010
0.0100
0.1000
1.0000
10.0000
0.00 0.05 0.10 0.15 0.20
Time post-homogenization (s)
Pb
De
ns
ity
(T
orr
)
Radius = 4.5m, tbc=600C
DAH, UW-FTI ARIES-IFE, April 2002, 10
Re-establishment of conditions suitable for target injection: do drops of aerosol remain?
t ~ 100-500 ms
Vapor density and temperature are suitable for beam transport and target injection?
Protecting liquid is re-established?
•We need to decide on the parameters space in which we want to identify operating windows, and what constitutes an acceptable design:
•Target Output
•Driver/Transport Method
•Radius
•Liquid
•Wall temperature
DAH, UW-FTI ARIES-IFE, April 2002, 11
Summary/Conclusions
We present results from a set of BUCKY simulations of the response of a thin liquid wall chamber to the threat spectrum of the C/C HIB target. Parameters considered were wall material (Pb or FLiBe), vapor composition (Xe or vapor
from the liquid) and vapor pressure. All variations considered lead to acceptable chambers from the point of view of ion deposition, vaporization thickness and
condensation rates, though these simulations do not include the effects of splashing or aerosolization.
•For the 4.5m radius chamber assaulted by the C/C HIB target:•All of the combinations of chamber gas, pressure, and wall considered lead to 10s of kilograms of mass vaporized at the end of 0.1ms.•Based on results presented last time, and absent splashing and aerosolization, recondensation should proceed quickly enough to maintain a 5Hz rep. rate.•More vapor does not necessarily provide more protection to the first wall, due to soft re-radiation with no time of flight spreading.
DAH, UW-FTI ARIES-IFE, April 2002, 12
Dry Wall Strawman Results
DD Target(LY)
DD Target(HY)
ID Target 1 ID Target 2
Driver KrF Laser KrF Laser Heavy IonBeam
Heavy IonBeam
Driver energy (MJ) 1.2 2.9 3.3 6Driver efficiency (%) 7 7 25 47Repetition rate (Hz) 14.2 5.3 4 4.9
Target NRL Direct-Drive Target
NRL Direct-Drive Target
HI Indirect-Drive Target
HI Indirect-Drive Target
Gain 128 138 139 63Target yield (MJ) 154 400 458 378Spectra From J.
Perkins’ calc.From J.Perkins’ calc.
From J.Perkins’ calc.
N/A
Photon energy (MJ) 2.14 6.07 115Burn product fast ion energy (MJ) 18.1 52.2 8.43Slow ion energy (MJ) 24.9 60.0 18.1Neutron energy (MJ) 109 279 316Gamma energy (MJ) 0.0046 0.0169 0.36Injection velocity (m/s) 400 400 100Initial temperature (K) 18 18 18Calculated D-T temperature rise(K)
Š1.8 Š1.8 <<1
ChamberChamber radius (m) 7.3 7.2 6.9 6.9Protective gas Xe Xe XeGas density (mTorr) 10 10 (D. Haynes) (D. Haynes)Number of penetrations 100 100 (W. Meier) (W. Meier)Size of penetrations @ FW (m) 0.1 0.1 (W. Meier) (W. Meier)Conductance (liter/s) 36,420 36,420 (J. Pulsifer) (J. Pulsifer)Continuous pumping flow rate(mbar-liter/s)
1,141 1,141 (J. Pulsifer) (J. Pulsifer)
DD Target(LY)
DD Target(HY)
ID Target 1 ID Target 2
Chamber WallChamber armor W W W WArmor thickness (mm) 0.1-1 0.1-1 0.1-1 0.1-1Structural material SiCf/SiC SiCf/SiC SiCf/SiC SiCf/SiCFirst wall thickness (mm) 4 4 4 4First wall channel dimension (mm) 5 5 5 5Coolant Pb-17Li Pb-17Li Pb-17Li Pb-17LiCoolant inlet pressure (MPa) ~1.5 ~1.5 ~1.5 ~1.5Coolant inlet temperature (°C) 529 529 529 529Coolant chamber wall outlettemperature (°C)
715 715 725 725
Coolant flow rate (kg/s) 2.19x104 2.13x104 1.8x104 1.8x104
Coolant pressure drop (MPa) ~1 ~1 ~1 ~1Maximum armor temperature (°C) (D. Haynes) (D. Haynes) (D. Haynes) (D. Haynes)Armor evaporation per shot (m) (D. Haynes) (D. Haynes) (D. Haynes) (D. Haynes)Armor evaporation per year (m) (D. Haynes) (D. Haynes) (D. Haynes) (D. Haynes)
Blanket ARIES-AT ARIES-AT ARIES-AT ARIES-ATStructural material SiCf/SiC SiCf/SiC SiCf/SiC SiCf/SiCBreeder Pb-17Li Pb-17Li Pb-17Li Pb-17LiTotal thickness (m) 0.4 0.4 0.4 0.46Li enrichment (%) 90 90 90 90Coolant (in series with FW) Pb-17Li Pb-17Li Pb-17Li Pb-17LiCoolant inlet pressure (MPa) ~0.7 ~0.7 ~0.8 ~0.8Coolant inlet temperature (°C) 715 715 725 725Coolant outlet temperature (°C) 1100°C 1100°C 1100°C 1100°CCoolant pumping power (MW) ~ 5 MW ~ 5 MW ~ 4 MW ~ 4 MW
BUCKY simulations for the LY DD, HY DD, and ID Target 1 have been performed. Protective gas requirement, armor
temperature and evaporation rates are reported.
DAH, UW-FTI ARIES-IFE, April 2002, 13
Dry Wall Strawman Results
Surface temperature response of dry wall strawmen
500
1000
1500
2000
2500
3000
3500
4000
4500
1.E-08 1.E-07 1.E-06 1.E-05
Time (ns)
Te
mp
era
ture
(C
)
ID1 DDLY DDHY
melting, albeit briefly
•ID1: 500mTorr
•DDLY: 10mTorr
•DDHY: 28mTorr
•N.B.: The effect of ion implantation is an important outstanding issue.
•Is brief melting acceptable? Desireable?
•No mass loss due to vaporization from thermal response.