1. ACT-1 design point definition
ARIES
UC San Diego
UW Madison
PPPL
Boeing
INEL
GIT GA
M. S. Tillack and C. E. Kessel
ARIES Project Meeting
26 – 27 Sept. 2012

2. Process of ACT1 design point selection (from May)
SCLL power core design is near final (builds & compositions).
“Aggressive” physics database will be regenerated.
System code will be pre-filtered and run over design space.
Design point selection process:
In the past, Kessel looked for a “balanced” set of parameters and chose a design point avoiding extremes.
Is there a better way?
Schedule for ACT 1d (hopefully the final design point)
Several new changes were made to the code (added about a month of delay) √ √ ✕
not yet
√ released
end of July

3. Code changes since May In DesignPoint.cpp
change Pdiv2o = power conducted to outboard divertor to Pdiv = total power to divertors
In powerflow.data
Generic current drive source efficiency from 0.5 to 0.4
Efficiency of plasma heating from 0.43 to 0.4
All other current drive efficiencies (NB, LH, etc) to 0.4
In Geometry.cpp (bucking cylinder calculation)
change s=2/3sy to s=sy
BT,max location at inside of TF rather than outside
Calculation of bucking cylinder thickness

4. Code changes since May: Bucking cylinder thickness and BT,max location
RTF,ave
Old stress balance
RBC,in
RBC,out
RTF,in
RTF,out
dwall
New (from Timoshenko, ARIES-1)
dscr=0 R
bucking
cylinder
TF coil
BT,max
Old
location
New
location

5. Code changes since May, continued
In setup.data
Use finger instead of plate divertor, since heat flux is high
In PowerFlow.data
reduce the ancillary power from 63 MW to 30 MW
In builds.data
The SCLL option ignores the structural ring. I added a 20-cm HT shield and removed the ring.
In DesignPoint.cpp
modify xl to use only outboard Pdiv
Pumping power formula averages over heat flux distribution

6. Code changes since May: divertor pumping power
Heat flux now has peak and off-peak zones
fdiv,peak= fraction of power deposited in peak region
Assumed fdiv,peak=0.5
Inboard and outboard calculated individually
All 4 zones use the pumping power formulas derived from analysis q x

7. Implementation
Use of the PPPL cluster has made it possible to scan the entire physics database (~500k pts) “overnight”
Post-filtering is performed on the full solutions now (rather than pre-filtering the physics solutions)
Filters for ACT1:
990 ≤ Pnet < 1010 MW
R ≤ 7 m
bN ≤ 0.05 (for a total b of 6)
fGW ≤ 1
H98 ≤ 1.7
fBS ≤ 0.925
Keep only points having COE within 5% of the minimum, arrange in order of increasing qdiv,ob and then choose a “robust” point (near other acceptable points)

8. Final design point (full output at aries.ucsd.edu/ASC)
Major radius
6.25 m
Toroidal field on axis 6 T
Peak field on coil 11
Fusion power
1813 MW
Thermal power
2016
Recirculated power
154
Alpha power
363
Fusion gain
42.5
Average n load at the FW
2.3
MW/m2
Peak n wall load
3.6
Peak FW heat flux
0.3
Peak divertor heat flux
10.6 (13.5)
Elongation
2.1
Triangularity
0.575
Normalized beta
5.75
Plasma current
10.9 MA
fGW 1
H98
1.65
fBC
0.905
Gross electric
1160 MW
Net electric
1006
Thermal conversion h
57.5 %
COE* 67
mill/kWh
* Subject to revision

9. Nuclear differences between ACT1b and ACT1d
Major radius
5.5
6.25 m
Fusion power
1804
1813 MW
n wall load (at plasma)
3.07
2.45
MW/m2
Area at SOL
502
628 m2
Asol*NWL/Pf
0.856
0.849