Los AlamosNational Laboratory

IFE Final Optics Neutron Irradiation

Scott Willms

With input from Jim Cobble (P-24), Terry Taddeucci, Steve Wender (LANSCE-3), D. Wayne Cooke, Kurt Sickafus, Mike Stevens, Robert Hanrahan, Kathleen

Alexander (MST-8), and Stuart Maloy (AAA-TPO)

Los Alamos National Laboratory

Presented February 6, 2001

At Naval Research Laboratory

Los AlamosNational Laboratory

Task summary

• Purpose: Determine the effect of fusion neutrons on the properties of IFE final optics

• FY01 deliverable: Expose optics sample to neutrons and perform pre- and post-irradiation examination

• Funding requirement: $300K

Los AlamosNational Laboratory

Damage mechanisms

• E-prime

• Si.

• 250 nm

• Peroxy

• Si-O-O.

• 600 nm

• Non-bonding oxygen hole center

• Si-O.

• 630 nm

Los AlamosNational Laboratory

Optical attenuation of fused silica fibers after irradiations of 1.4 x 1021 and 1.1 x 1023 n/m2

--D.W. Cooke, B.L. Bennett, E.H. Farnum; J. Nuc. Materials 232, 214-218 (1996)

<1 ppm OH fiber 600-800 ppm OH fiber

Los AlamosNational Laboratory

Task steps

• Obtain samples

• Pre-irradiation characterization

• Irradiation

• Post-irradiation examination

• Effects mitigation, if needed, and re-examination

• Modeling

Los Alamos Neutron Science Center

800-MeV Linear Accelerator

APT MaterialsIrradiation

& Isotope Production

LANSCE Visitor’s Center

Manuel Lujan Jr.Neutron Scattering

Center

WeaponsNeutron Research

Proton StorageRing

ProtonRadiography

Neutron ResonanceSpectroscopy

Future IPF

Los AlamosNational Laboratory

Irradiation

• WNR

• 1-600 MeV spectrum

• 2.5 x 1010 neutrons/m2/s

• 1 month -> 6 x 1016 neutrons/m2

• DT Neutrons

• 14 MeV

• 8 x 1011 neutrons/m2/s at 10 cm

• 1 week -> 5 x 1017 neutrons/m2

• Dose determination

• Room temperature

Los AlamosNational Laboratory

Samples

• Materials

• Fused silica

• CaF2

• Reflective optics?

• Sizes

• Numbers

• Surface preparation

• Coatings

Los AlamosNational Laboratory

Pre- and post-irradiation characterization

• Transmissive property measurements

• Ring-down reflectometer

• Optical spectroscopy (250-2000 nm)

• Single wavelength test?

• Other

• Other measurements

• Transmission electron spectroscopy (TEM)

• Electron spin resonance (ESR)

• Energy-filtered electron diffraction (EFED)

• Extended X-ray absorption fine structure (EXAFS)

Los AlamosNational Laboratory

Further tasks

• Effects mitigation

• Annealing

• Optical bleaching

• Modeling

• Point defect models

Los AlamosNational Laboratory

Task assignmentsTask Lead

Task coordination Scott Willms (STB-FES)

Optics samples Steve Payne (LLNL)

Mark Tillack (UCSD)

Neutron irradiation Terry Taddeucci (LANSCE-3)

Pre and Post irradiation examination Transmissive properties Other property measurements

Modeling

Wayne Cooke (MST-8)Ralph Berggren (P-24)Kurt Sickafus (MST-8)/ Stuart Maloy (AAA-TPO)Cooke/Sickafus/Maloy

Los AlamosNational Laboratory

Task timeline

ID Task Name

1 Obtain samples

2 Perform pre-irradiation tests

3 Irradiate

4 Post-irradiation test

5 Modeling

6 Report

3/5Jan Feb Mar Apr May Jun Jul Aug Sep Oct

2001 2002