May 2005 PFC Coord Comm Planning Mtng, PPPL

FY06 PISCES Program Plans

G.R.Tynan

for

G. Antar, M. Baldwin, R.W. Conn, R. Doerner, D. Gray, A. Grossman, J. Hanna, E.

Hollmann, C. Laizhong, S. Luckhardt, F. Najmabadi, D. Nishijima, E. Oyarzabal, R. Seraydarian, M. Shimada, G.R. Tynan, Y.

Zheng, J. Yu

Center for Energy Research

UCSD

May 2005 PFC Coord Comm Planning Mtng, PPPL

PISCES Program Management Has Been Re-Organized

• Tynan & Najmabadi are Faculty PIs (Conn still Emeritus PI)

• Doerner Leading Materials Program• Tynan Leading Physics Program• Future Program Leadership Determined in

Concert w/ DOE Discussions

May 2005 PFC Coord Comm Planning Mtng, PPPL

FY06 Program Elements & Balance

• ITER Support (60%)– 5 Science FTE/4 Tech Staff

• Enabling PMI Physics & Technology (30%)– 3 Science FTE/0.5 FTE Tech Staff/4 Grad-

Students

• ALPS Support (10%)– 0.5 Science FTE/0.5 FTE Tech Staff

May 2005 PFC Coord Comm Planning Mtng, PPPL

FY06 PISCES ITER Support (60%)

• EU-US Collaboration Continuing– ELM Heat Pulse Transient Effect on Mixed

Materials (UCSD/IPP-Garching)

• Continue Be/W & Be/C Interaction Studies– Parametric dependencies, D-retention & removal,

mix layer temporal evolution

• PMI Modeling Validation

May 2005 PFC Coord Comm Planning Mtng, PPPL

Motivation for PISCES Mixed Materials Studies

• UC San Diego PISCES and EFDA are investigating the influence of Beplasma impurities on exposed materialsinteractions relevant to ITER.

• The ITER design: Be first-wall,W divertor, C (graphite) strike points.

• Diverted plasma expected to ‘dirty’:Eroded Be impurity conc. up to 10 %.

PISCES-B ExperimentsSimulation This Region

May 2005 PFC Coord Comm Planning Mtng, PPPL

45 o

Rad ial plasma transport shield

Cooled target assembly

-

Cooled Mo limiter

Resistive heater coils

PISCES -B Plasma column

Target

Deposition coupon

102 mm

153 mm

76 mm

Plasma source

Magnetic axis

Thermo - couple

Heatable deposition probe assembly

Evaporative Be Impurity seeding

PISCES-B Mixed Material ELM Simulations in FY06(US-EU Collaboration)

time

Vplasma

Vbi

as(t

)

Programmed Waveform

Objective: Study Mixed Mat’l Response to Intense Pulsed Heat Flux

Transient Heat Flux4 - 40 MW/m2

May 2005 PFC Coord Comm Planning Mtng, PPPL

Plasma conditions:

D ~3x1018 cm-2 s-1, Te~ 6eV, ne~ 1012 cm-3,

T ~500 K, D Ion Fluence ~2x1022 cm-2

No Be seeding m = - 62 mg

ATJ graphiteNot exposed

~0.1 % Be seeding m = - 5 mg AES - 85 % Be, 10% O & 5% C

PISCES Will Study Temporal Evolution of Be/C & Be/W Surfaces in FY06

Objective: Understand Surface Coverage & Be Alloying

May 2005 PFC Coord Comm Planning Mtng, PPPL6

00.20.40.60.8

11.2

0

30

6090

n Be/n

Be(

=0)

d = 10 mm

d = 16 mm

d = 22 mm

cosine20050425

Ei = 150 eV

Studies of Be Sputtering Yield v. Exit Angle in FY06

Be target (~ 2.1 cm dia.)

z

y or r

Be

5-6

cm

B

z = 152 mm

Geometry

0

0.5

1

1.5

2

-30 -20 -10 0 10 20 30

measured

fit

Be

I in

tens

ity [

101

6 p

h/(s

m2 s

r)]

y [mm]

20050425, 4436_04

Ei = 150 eV @ z = 2 mm

Abel InvertTo get

(r,z) Dependence

Spatially ResolvedBe-I & Be-II MeasurementsPossible Study Be Ion Transport

May 2005 PFC Coord Comm Planning Mtng, PPPL

7

00.20.40.6

0.81

1.2

0

30

6090

d = 10 mmd = 16 mmd = 22 mmcosine

n Be/n

Be(

=0)

20050422

Ei = 50 eVExperiment

00.20.40.6

0.81

1.2

0

30

6090

d = 10 mmd = 16 mmd = 20 mmcosine

n Be/n

Be(

=0)

Ei = 50 eV

WBC simulationWBC monte carlo code simulation (by J.N. Brooks) assumed cosine angular distribution.

Identify Physics that Leads to Difference Between Model & Expt

And Incorporate in Model (If Needed)

In experiments, nBe does not become small at large angle ( > 60 deg.).

At larger d, the distribution becomes closer to cosine distribution for point source.

Deviation from cosine distribution?

Strong diffusion?

--

--

May 2005 PFC Coord Comm Planning Mtng, PPPL

FY06 Enabling PMI Physics & Technology Plans

• IR-Absorption Spectroscopy for CxDy Concentration Measurements

• Basic Erosion Studies for Model Validation• Measure Edge/SOL Transport & Flows w/

Time-resolved Imaging Diagnostic• Source Technologies for New Physics

Simulations

May 2005 PFC Coord Comm Planning Mtng, PPPL

Molecular Infra-red Absorption (MIRA) Diagnostic for Carbon Chemical Erosion Studies

• Choose IR for resonant molecular interaction

• Use lock-in to increase SNR

• Study CxDy radical formation & transport in front of divertor plate mat’l

Objective: Link CD Radical Concentration with CD4 Production & Then Use Result for Tokamak Divertor Physics

May 2005 PFC Coord Comm Planning Mtng, PPPL

Basic Studies of Material Erosion: Carbon Cluster Ejection into Noble Gas Plasma

CarbonTarget

Plasmasource

Vbias Ionizer

QMS

ExperimentalGeometry QMS

Target

050

100150200250300

0 5 10 15 20 25 30

Co

unt R

ate

(c/

s)

Energy (eV)

C2 Cluster Energy Spectrum

C2 Dimer Y()

C3 Trimer Y()

May 2005 PFC Coord Comm Planning Mtng, PPPL

Edge and SOL Physics in FY06

Objective: Develop Measurement of Large-scale Edge/SOL Flows to Understand Erosion/Redep/Retention in SOL/Divertor

End-on View of PlasmaIn Linear Plasma Device Infer Propagation Speed From

Time-delay Scheme & Validate w/ ExB Drift Probe Measurements…

…Then Apply to Large-Scale Fast-Framing Images of

Tokamak Edge/SOL to find Plasma Flowfield

May 2005 PFC Coord Comm Planning Mtng, PPPL

Other Topics for FY06

• Transient Effects on Gas Target Divertor

• Birth Mechanism for “Blobs”• Advanced Edge Turbulence

Analysis Technique Development

May 2005 PFC Coord Comm Planning Mtng, PPPL

FY06 Program Elements & Balance

• ITER Support (60%)– 5 Science FTE/4 Tech Staff

• Enabling PMI Physics & Technology (30%)– 3 Science FTE/0.5 FTE Tech Staff/4 Grad-

Students

• ALPS Support (10%)– 0.5 Science FTE/0.5 FTE Tech Staff