# Presentation: 667403

## FIRE Physics/Engineering Integration

- C. Kessel
- Princeton Plasma Physics Laboratory
- FIRE Project Meeting 11/7/2002

## Outline

**Reference H-mode Scenario**
**Lower li from pedestals leads to higher coil currents**
**Define operating range**
**Advanced Tokamak Scenario**
**Very low li from bootstrap and CD leads to higher coil currents**
**Define operating range**
- Plasma Control
- Plasma Startup
- RWM Coils
- Power Handling and Limitations in AT plasmas
- Other Analysis
- Disruptions
- Current Drive/Heating
- Physics Validation Review
- Topical areas

## Reference H-mode Discharge Scenario

- alpha

- auxiliary

- ohmic

- Ip=7.7 MA, Bt=10 T
- N=1.85, H98(y,2)=1.05

## Improved Plasma Modeling Show Lower li Values for Reference Discharge

- Temperature pedestal leads to broader current profile and lower li
- li values around 0.65 for reference case, rather than 0.9
- Leads to smaller CS1 current, but larger CS2,3 and PF1,2 currents, and sloshes more current into PF3

## Lower li Values Lead to Larger Coil Currents

| EOB Currents, MA | Li=0.9
=21.7 Wb | Li=0.65
=21.7 Wb | Li=0.6
=21.7 Wb | Li=0.55
=21.7 Wb | Li=0.65
=26.7 Wb |
| --- | --- | --- | --- | --- | --- |
| CS1 | -12.68 | -10.25 | -9.78 | -8.97 | -12.77 |
| CS2 | 2.10 | -4.62 | -5.93 | -8.54 | -6.85 |
| CS3 | 2.19 | 6.21 | 6.67 | 8.67 | 5.80 |
| PF1 | 4.54 | 6.10 | 6.60 | 7.00 | 5.00 |
| PF2 | 4.54 | 6.10 | 6.60 | 7.00 | 5.00 |
| PF3 | -2.06 | -5.92 | -6.93 | -8.20 | -5.97 |
| PF4 | -4.30 | -2.78 | -2.38 | -1.87 | -2.87 |

- p=0.84, N=1.85

## Recent Simulations Show That V-s Consumption is Lower

- Reference scenarios show that fewer V-s are required to rampup and sustain the plasma
- Previous:
-      (ramp)=41.2 V-s
-      (flattop)=4.5V-s
- New:
-      (ramp)=39 V-s
-      (flattop)=4.2 V-s
- Need to determine flux states that are within stress allowables and provide sufficiently low coil currents (thermal)

## Fiducial Equilibria Reference Discharge

| MA | IM | SOD | SOH | SOB | EOB | EOH | EOD |
| --- | --- | --- | --- | --- | --- | --- | --- |
| CS1 | 9.90 | 8.84 | -8.62 | -10.6 | -12.8 | -12.4 | 1.23 |
| CS2 | 6.27 | 5.60 | 8.06 | -5.24 | -6.85 | 3.52 | 0.79 |
| CS3 | 4.02 | 3.59 | 5.64 | 6.64 | 5.80 | -4.14 | 0.49 |
| PF1 | 3.26 | 2.91 | 5.60 | 5.80 | 5.00 | 2.60 | 0.37 |
| PF2 | 4.31 | 3.84 | 5.60 | 5.80 | 5.00 | 2.60 | 0.45 |
| PF3 | 0.22 | 0.20 | -7.15 | -5.85 | -5.97 | -1.58 | 0.00 |
| PF4 | 0.26 | 0.23 | -4.20 | -2.82 | -2.87 | -2.69 | 0.00 |
| Ip | 0.0 | 0.1 | 7.7,5.8 | 7.7 | 7.7 | 5.0 | 0.1 |
| li | 1.5 | 1.5 | 1.0 | 0.65 | 0.65 | 1.0 | 1.5 |
| p | 0.2 | 0.2 | 0.2 | 0.85 | 0.85 | 0.2 | 0.2 |
|  | -18.5 | -16.5 | 10.0 | 22.5 | 26.7 | 18.7 | -2.1 |
| time | 0- | 0+ | 5.0 | 7.0 | 27.0 | 30.0 | 34.0 |

## Variation of li and  at EOB

| MA | Li=0.55
=21.7 | Li=0.55
=26.7 | Li=0.55
=31.7 | Li=0.65
=21.7 | Li=0.65
=26.7 | Li=0.65
=31.7 | Li=0.85
=21.7 | Li=0.85
=26.7 | Li=0.85
=31.7 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| CS1 | -9.12 | -11.7 | -14.2 | -10.3 | -12.8 | -15.4 | -12.1 | -14.4 | -17.0 |
| CS2 | -7.69 | -9.70 | -11.7 | -4.62 | -6.85 | -8.43 | 1.52 | -1.83 | -3.84 |
| CS3 | 7.08 | 6.25 | 5.44 | 6.21 | 5.80 | 4.18 | 1.65 | 3.37 | 2.54 |
| PF1 | 7.40 | 6.40 | 5.40 | 6.10 | 5.00 | 4.20 | 5.10 | 3.46 | 2.46 |
| PF2 | 7.40 | 6.40 | 5.40 | 6.10 | 5.00 | 4.20 | 5.10 | 3.46 | 2.46 |
| PF3 | -8.43 | -8.55 | -8.66 | -5.92 | -5.97 | -6.22 | -2.74 | -2.44 | -2.56 |
| PF4 | -1.80 | -1.87 | -1.94 | -2.78 | -2.87 | -2.90 | -4.11 | -4.30 | -4.38 |

- p=0.85, N=1.85

## AT Discharge Scenario

- Ip=4.5 MA, Bt=6.5 T, N=4.1, Zeff=2.2,
- H98(y,2)=1.75, q95=4.0, qmin=2.7,
- I(FW)=0.2 MA, I(LH)=0.83 MA, I(BS)=3.5 MA,
- P(FW)=7 MW, P(LH)=25 MW

## Advanced Tokamak Scenarios Have Very Low li and Lower Ip

- Ip=4.0-5.5 MA, Bt=6.5-8.5T
- Ip can not be too low or we’ll loose too many alphas from ripple
- Inductive + non-inductive
- rampup ----> consumes 19-22 V-s, what is final flux state??
- 100% non-inductive in flattop
- li(3) = 0.42, N=4.2
- _Flattop times = 13-40s (from P__fusion__ of 300-100 MW)_
- Divertor coils (PF1&2)are driven to high currents leading to Ip limits

## AT Operating Space Shows Pfusion Ranging from 100-300 MW

- VV nuclear heating provides a 4000 MW-s limit on pulse length
- What are TF pulse length limits at these fields and Pfusion?
- Flattop times range from 13-40 s, so PF coils will remain at their current levels for these times

## Slide 12

## AT Plasmas at Bt=6.5 T, li=0.35, N=5.0

| Ip=5.25
q95=3.3 | =7.5 | =10.0 | =12.5 | =15.0 | =17.5 |
| --- | --- | --- | --- | --- | --- |
| CS1 (MA) | 1.44 | 0.16 | -1.14 | -2.43 | -3.71 |
| CS2 | -6.90 | -7.90 | -8.77 | -9.75 | -10.75 |
| CS3 | 7.92 | 7.50 | 6.85 | 6.41 | 6.00 |
| PF1 | 7.84 | 7.34 | 6.90 | 6.40 | 5.90 |
| PF2 | 7.84 | 7.34 | 6.90 | 6.40 | 5.90 |
| PF3 | -7.43 | -7.49 | -7.59 | -7.64 | -7.70 |
| PF4 | -0.95 | -0.98 | -1.01 | -1.05 | -1.09 |
| Ip=4.5
q95=4.0 | =7.5 | =10.0 | =12.5 | =15.0 | =17.5 |
| CS1 (MA) | 1.25 | -0.02 | -1.29 | -2.56 | -3.84 |
| CS2 | -6.25 | -7.27 | -8.27 | -9.25 | -10.3 |
| CS3 | 6.38 | 5.98 | 5.57 | 5.15 | 4.75 |
| PF1 | 6.50 | 6.00 | 5.50 | 5.00 | 4.50 |
| PF2 | 6.50 | 6.00 | 5.50 | 5.00 | 4.50 |
| PF3 | -6.10 | -6.18 | -6.24 | -6.30 | -6.37 |
| PF4 | -1.08 | -1.11 | -1.15 | -1.18 | -1.08 |

## AT Plasmas at Bt=8.5 T, li=0.35, N=3.5

| Ip=5.5
q95=4.0 | =7.5 | =10.0 | =12.5 | =15.0 | =17.5 |
| --- | --- | --- | --- | --- | --- |
| CS1 (MA) | 1.36 | 0.07 | -1.22 | -2.52 | -3.8 |
| CS2 | -7.37 | -8.29 | -9.24 | -10.1 | -11.1 |
| CS3 | 8.57 | 7.98 | 7.49 | 6.91 | 6.00 |
| PF1 | 8.40 | 7.94 | 7.46 | 7.00 | 6.00 |
| PF2 | 8.40 | 7.94 | 7.46 | 7.00 | 6.00 |
| PF3 | -8.20 | -8.29 | -8.36 | -8.44 | -8.50 |
| PF4 | -0.72 | -0.75 | -0.78 | -0.81 | -0.85 |
| Ip=4.65
q95=5.0 | =7.5 | =10.0 | =12.5 | =15.0 | =17.5 |
| CS1 (MA) | 0.92 | -0.39 | -1.68 | -2.94 | -4.22 |
| CS2 | -6.42 | -7.20 | -8.20 | -9.20 | -10.2 |
| CS3 | 6.92 | 6.10 | 5.70 | 5.29 | 4.88 |
| PF1 | 6.70 | 6.30 | 5.80 | 5.30 | 4.80 |
| PF2 | 6.70 | 6.30 | 5.80 | 5.30 | 4.80 |
| PF3 | -6.46 | -6.59 | -6.64 | -6.71 | -6.77 |
| PF4 | -0.92 | -0.95 | -0.98 | -1.01 | -1.05 |

## Fiducial Equilibria 6.5T AT Discharge

| MA | IM | SOD | SOH | SOF | SOB | EOB | EOH | EOD |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| CS1 | 4.88 | 3.82 | -1.59 | -2.69 | -1.35 | -1.35 | -5.20 | 0.12 |
| CS2 | 3.10 | 2.44 | -3.87 | -9.00 | -8.09 | -8.09 | -0.76 | 0.08 |
| CS3 | 1.97 | 1.50 | 3.63 | 6.77 | 5.38 | 5.38 | 1.50 | 0.00 |
| PF1 | 1.59 | 1.21 | 3.60 | 5.50 | 5.50 | 5.50 | 1.50 | 0.00 |
| PF2 | 2.07 | 1.60 | 3.60 | 5.50 | 5.50 | 5.50 | 1.50 | 0.00 |
| PF3 | 0.10 | 0.08 | -4.20 | -7.17 | -6.20 | -6.20 | -0.58 | 0.00 |
| PF4 | 0.11 | 0.07 | -1.65 | -0.40 | -1.16 | -1.16 | -1.73 | 0.00 |
| Ip | 0.0 | 0.1 | 2.75 | 4.50 | 4.50 | 4.50 | 3.00 | 0.10 |
| li | 1.5 | 1.5 | 0.40 | 0.35 | 0.35 | 0.35 | 1.0 | 1.5 |
| p | 0.2 | 0.2 | 1.0 | 1.5 | 2.5 | 2.5 | 0.5 | 0.2 |
|  | -9.0 | -7.0 | 6.0 | 12.5 | 12.5 | 12.5 | 8.5 | 0.0 |
| time | 0- | 0+ | 4.0 | 7.0 | 10.0 | 35.0 | 38.0 | 42.0 |

## Plasma Equilibria and PF Coil Currents

- Reference H-mode plasma (full Ip and Bt)
- Range of current profiles:  0.55 < li(3) < 0.85
- Range of pressures: 1.50 < N < 3.0
- Range of EOB flux states: 21.7 <  < 31.7
- Plasma shape or aspect ratio variations???
- Advanced tokamak plasmas
- Range of current profiles: 0.35 < li(3) < 0.55
- Range of pressures: 2.50 < N < 5.0
- Range of flattop flux states: chosen to minimize heating and depends on flattop time (determined by Pfusion)
- What is the Ip limit to keep coil currents down?
- Plasma shape or aspect ratio variations???
- Lower li operating space requires redesign of PF1 and PF2
- PF3 and 4 should be resized