Ultrasonic characterization of inertial Ultrasonic characterization of inertial confinement fusion targetsconfinement fusion targets

KSM EDITED VERSIONKSM EDITED VERSION

High Average Power Laser (HAPL) Program MeetingOctober 27-28, 2004

Princeton Plasma Physics LaboratoryPrinceton, New Jersey, USA

L.J. Bonda, M.S. Gooda and D. Schroenb

aaPacific Northwest National LaboratoryPacific Northwest National LaboratoryRichland, Washington, USARichland, Washington, USA

bbSchafer Corporation, Livermore, California, USASchafer Corporation, Livermore, California, USA

Ultrasonic characterization of inertial Ultrasonic characterization of inertial confinement fusion targetsconfinement fusion targets

KSM EDITED VERSIONKSM EDITED VERSION

High Average Power Laser (HAPL) Program MeetingOctober 27-28, 2004

Princeton Plasma Physics LaboratoryPrinceton, New Jersey, USA

L.J. Bonda, M.S. Gooda and D. Schroenb

aaPacific Northwest National LaboratoryPacific Northwest National LaboratoryRichland, Washington, USARichland, Washington, USA

bbSchafer Corporation, Livermore, California, USASchafer Corporation, Livermore, California, USA

Target Characterization RequirementsTarget Characterization RequirementsTarget Characterization RequirementsTarget Characterization Requirements

Inspection of challenging materials in small geometries – spheres and cylinders maximum dimensions few mmLow density foam: Divinyl Benzene (DVB) foam

shells Cylindrical samples of TPX

foam – shells and cylinders for density anomalies and dimensions

Cryogenic targets at ~ 15K which contain deuterium ice layer

BACKGROUNDBACKGROUNDBACKGROUNDBACKGROUND

High Pressure Gas-Coupled Acoustic MeasurementsPulse-echo demonstrated by: Wickramasinghe & Petts (1980)Transmission measurements (Bond 1992)High pressure gas has lower attenuation for ultrasoundNo liquid couplant requiredRecent application membrane compaction and recovery (Reinsch et. al. 2000)Preliminary data reported HAPL MEETINGS February & June 2004

BACKGROUND BACKGROUND (cont’d)(cont’d)BACKGROUND BACKGROUND (cont’d)(cont’d)

RECENT ACTIVITIES:RECENT ACTIVITIES:Data taken on TPX Foam Cylinders and DVB Foam Spherical ShellGas-coupled: Initial 1-D scanned Images from TPX Foam SamplesWater-coupled: Preliminary data to characterize DVB Foam Spherical Shell Capsules just after gellation Measure wall thickness and concentricity Proposed Technique: Use 50-MHz transducer array Benefit: ultrasonic technique would eliminate multiple

chemical exchanges required by the current optical technique, expedite production, and significantly reduce the solvent waste stream.

High Pressure Gas CoupledUltrasound (HPGCU) SystemHigh Pressure Gas CoupledUltrasound (HPGCU) System

A.A. Pressurized Pressurized Gas CylinderGas CylinderB. Pressure Vessel B. Pressure Vessel C. C. Pressure Pressure GageGage ReadRead Out Out D.D. Ultrasonic Ultrasonic ElectronicsElectronicsE.E. Data Cables to Data Cables to

ComputerComputerF.F. Motor ControllerMotor ControllerG.G. Motor InterfaceMotor InterfaceH. Camera MonitorH. Camera Monitor

of Scanner within of Scanner within Pressure VesselPressure Vessel

AABB

CC

DDDD DD

EE

FF

GGHH

Components within Pressure VesselComponents within Pressure VesselComponents within Pressure VesselComponents within Pressure Vessel

Pressure Pressure VesselVessel

Pressure Vessel

Head Shaft

Camera Monitor

Transducer Gimbal

Transducer

Linear Slide

Motor

Se

nso

r P

osi

tion

X (

µm

)

Co

lor-

Sca

le M

od

ula

ted

b

y A

mp

litu

de

Image Concept

Sample Mount

Sample

Depth (µm)

1-Axis Scanner

Transducer Focal CharacteristicsTransducer Focal CharacteristicsTransducer Focal CharacteristicsTransducer Focal Characteristics

(Not to Scale)

9 mm

0 2 4 6 8 10 12 14 16 Lateral Displacement (mm)

ResResolution Pattern for Transducer Characterization A Pattern of 0.125-mm Diameter, Nylon Monofilament Reflectors

Transducer: 3-MHz Frequency, 12.5-mm Focal Length

Amplitude-Color KeyDepth Displacement (mm)

8

10

12

14

16

18

Transducer Characterization

Reference

Converging Field

Diverging Field

Surface Metrology CharacterizationSurface Metrology CharacterizationA EDCB GF

H

H

A EDCB GF

H

H

H

50 µm Surface Steps in Aluminum. A. 0 µm Datum, B. 50 µm, C. - 100 µm,D. 150 µm, E. - 200 µm, F. 250 µm, G. - 300 µm, H. Photographs

10 µm Surface Steps in Aluminum. A. 0 µm Datum, B. 10 µm, C. - 20 µm,D. 30 µm, E. - 40 µm, F. 50 µm, G. - 60 µm, H. Photographs

50 µm Surface Steps in TPX Foam. A. 0 µm Datum, B. - 50 µm,C. 100 µm, D. - 150 µm, E. 200 µm, F. - 250 µm, G. 300 µm,H. Photographs

H

EDC GF

A B

2 mm

2 mm

2 mm

Internal Metrology CharacterizationInternal Metrology Characterization

Not to Scale

0 5 10 15Lateral Displacement (mm)

Relative Depth (mm)

0 2 4 6 81012

Reference Step Block with Water Chamber

0 5 10 15 20 25 Lateral Displacement (mm)

Relative Depth (mm)

0 1 2 Plastic Sample Holder

TPX Foam Reference Step Block

TPX Foam SamplesTPX Foam SamplesTPX Foam SamplesTPX Foam Samples

Sample Description MaterialsSurface Steps 10 µm Aluminum

and TPX Foam

Surface Steps 50 µm Aluminum and TPX Foam

Thickness Change 0.25 mm

Plastic

Thickness Change 1.00 mm

TPX Foam

Density Discontinuity TPX Foam

10 µm 20 µm 30 µm 40 µm 50 µm 60 µm Step Discontinuities

2 mm22 mm

5 mm

(A) Design A: Step Discontinuity (10 µm Increments)

50 µm 100 µm 150 µm 200 µm 250 µm 300 µm Step Discontinuities

(C) Design C: Step Discontinuity (50 µm Increments)

6 mm 6 mm

(B) Design B: Dropped

10 µm 20 µm 30 µm 40 µm 50 µm 60 µm Step Discontinuities

2 mm22 mm

5 mm

(A) Design A: Step Discontinuity (10 µm Increments)

50 µm 100 µm 150 µm 200 µm 250 µm 300 µm Step Discontinuities

(C) Design C: Step Discontinuity (50 µm Increments)

6 mm 6 mm

(B) Design B: Dropped

4 mm

Foam Thickness 8.0 mm 7.0 mm 6.0 mm 5.0 mm 4.0 mmPoly Carbonate 3.50 mm 3.25 mm 3.00 mm 2.75 mm 2.50 mm

Thickness

28 mm

8 mm 4 mm

100 µm 300 µm 500 µm200 µm 400 µm 600 µm

2 mm22 mm

6 mm

●● ● ● ●

●

Polystyrene Cylinder

(50-µm diameter)●

●

●●

●Polystyrene

Cylinder(100-µm diameter)

1.0 mm

Depth

2.0 mm3.0 mm

4.0 mm5.0 mm

6 mm 6 mm

Not to Scale

Preliminary Data to Characterize DVB Foam Preliminary Data to Characterize DVB Foam Spherical Shell Capsules After Gellation:Spherical Shell Capsules After Gellation:

Thickness Measurement (WATER COUPLED)

Preliminary Data to Characterize DVB Foam Preliminary Data to Characterize DVB Foam Spherical Shell Capsules After Gellation:Spherical Shell Capsules After Gellation:

Thickness Measurement (WATER COUPLED)Amplitude (Screen Height Percent)

Frequency (MHz)

Time (µs) is Proportional to Thickness

Outer Surface: 0 µm

Inner Surface: 300 µm

Excellent resolution exists to quantify thicknessClassic phase reversal pattern exists between responses Outer Surface: Water to

DVB saturated with water Inner Surface: DVB

saturated with water to water

High confidence exists in signal interpretation.

Amplitude (Screen Height Percent)

Peak Frequency:

37 MHz

DVB Spherical Shell

Preliminary Data to Characterize Metal Spherical Preliminary Data to Characterize Metal Spherical Shells During Production for Quality Control: Shells During Production for Quality Control:

ThThickness Measurement Using Discrete Signals

Preliminary Data to Characterize Metal Spherical Preliminary Data to Characterize Metal Spherical Shells During Production for Quality Control: Shells During Production for Quality Control:

ThThickness Measurement Using Discrete Signals AB

Amplitude (Screen Percentage)

Time (Time (µsµs))

A BGated

Portion of Signal

Δt

Sample 1:90 µm ThicknessΔt = 0.071 µs

Sample 2: 139 µm Thickness Δt = 0.113 µs

Sample 3: 70 µm ThicknessΔt = 0.056 µs

Source of samples: Haibo Huang, General Atomics

Surrogate: Glow Discharge Polymer coated

PAMS shell

Preliminary Data to Characterize Metal Spherical Preliminary Data to Characterize Metal Spherical Shells During Production for Quality Control: Shells During Production for Quality Control: ThThickness Measurement Using Spectroscopy

Preliminary Data to Characterize Metal Spherical Preliminary Data to Characterize Metal Spherical Shells During Production for Quality Control: Shells During Production for Quality Control: ThThickness Measurement Using Spectroscopy

Amplitude (Screen Percentage)

Frequency (MHz)

Amplitude Spectrum of Gated Signal

Δf = 1/Δt

Δf

Sample 1:90 µm Thickness

Sample 2: 139 µm Thickness

Sample 3: 70 µm Thickness

Source of samples: Haibo Huang, General Atomics

ConclusionsConclusions

Acoustic microscopy has unique characterization capabilities for two critical steps in the target fabrication production facility.It can characterize gelled (opaque) foam shells without solvent exchanges to an indexed mated solvent. Optical characterization requires an exchange from isopropanol and future processing steps require an exchange back to isopropanol.  Ultrasonic characterization eliminates two solvent exchange steps with the time and solvent waste associated with them.  It can characterize layered targets in both room temperature and a cryogenic environment.  Ultrasonic characterization could be done just prior to injection to decrease the number of shells that do not produce high yield.

ReferencesReferencesReferencesReferences

Bond, L.J. (1992) Through transmission gas and pulsed water-coupled microscopy of electronic packaging and composite materials. Report to NIST, University of Colorado at Boulder.

Reisch, V.E., Greenberg, A.R., Kelley, S.S., Peterson, R. and Bond, L.J. (2000) “A new technique for the simultaneous real-time measurement of membrane compaction and performance during exposure to high-pressure gas.” J. Membrane Science 171 pp. 217-228.

Wickramasinghe, H.K. and Petts, C.R. (1980) Gas medium acoustic microscopy, in Scanning Image Microscopy, ed. E.A. Ash, Academic Press (London) pp. 57-70.

For more information contact:For more information contact:

Leonard J. Bond, Ph.D.Leonard J. Bond, Ph.D.Laboratory FellowLaboratory FellowPacific Northwest National LaboratoryPacific Northwest National LaboratoryP.O. Box 999, K5-26P.O. Box 999, K5-26Richland, WA 99352Richland, WA 99352email: email: leonard.bond@pnl.govPhone: 509-375-4486Phone: 509-375-4486

Morris S. Good, Ph.D.Morris S. Good, Ph.D.Staff Scientist and EngineerStaff Scientist and EngineerPacific Northwest National LaboratoryPacific Northwest National LaboratoryP.O. Box 999, K5-26P.O. Box 999, K5-26Richland, WA 99352Richland, WA 99352email: email: morris.good@pnl.govPhone: 509-375-2529Phone: 509-375-2529

For more information contact:For more information contact:

Leonard J. Bond, Ph.D.Leonard J. Bond, Ph.D.Laboratory FellowLaboratory FellowPacific Northwest National LaboratoryPacific Northwest National LaboratoryP.O. Box 999, K5-26P.O. Box 999, K5-26Richland, WA 99352Richland, WA 99352email: email: leonard.bond@pnl.govPhone: 509-375-4486Phone: 509-375-4486

Morris S. Good, Ph.D.Morris S. Good, Ph.D.Staff Scientist and EngineerStaff Scientist and EngineerPacific Northwest National LaboratoryPacific Northwest National LaboratoryP.O. Box 999, K5-26P.O. Box 999, K5-26Richland, WA 99352Richland, WA 99352email: email: morris.good@pnl.govPhone: 509-375-2529Phone: 509-375-2529