Constitutive Models for the Viscoelastic Behavior of Polyimide Membranes at Room and Deep Cryogenic Temperatures

Bhandarkar, Suhas; Betcher, Jacob; Smith, Ryan; Lairson, Bruce; Ayers, Travis

doi:10.13182/FST15-218

Title: Constitutive Models for the Viscoelastic Behavior of Polyimide Membranes at Room and Deep Cryogenic Temperatures

Abstract

Targets for ICF shots on NIF typically use ~500nm thin polyimide films with a coating of 25nm of aluminum as windows that seal the laser entrance hole or LEH. Their role is to contain the hohlraum gas and minimize the extraneous infra-red radiation getting in. This is necessary to precisely control the hohlraum thermal environment for layering inside the capsule with solid deuterium-tritium at 18K. Here, we use our empirical data on the bulging behavior of these foils under various different conditions to develop models to capture the complex viscoelastic behavior of these films at both ambient and cryogenic temperatures. The constitutive equations derived from these models give us the ability to quantitatively specify the film’s behavior during the fielding of these targets and set the best parameters for new target designs.

Authors:

Bhandarkar, Suhas ^[1]; Betcher, Jacob ^[2]; Smith, Ryan ^[2]; Lairson, Bruce ^[2]; Ayers, Travis ^[2]

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Luxel Corp., Friday Harbor, WA (United States)

Publication Date:: Thu Jun 30 00:00:00 EDT 2016

Research Org.:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1343043

Report Number(s):: LLNL-JRNL-677537
Journal ID: ISSN 1536-1055; TRN: US1701814

Grant/Contract Number:: AC52-07NA27344

Resource Type:: Accepted Manuscript

Journal Name:: Fusion Science and Technology

Additional Journal Information:: Journal Volume: 70; Journal Issue: 2; Journal ID: ISSN 1536-1055

Publisher:: American Nuclear Society

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; 42 ENGINEERING

Citation Formats


                    Bhandarkar, Suhas, Betcher, Jacob, Smith, Ryan, Lairson, Bruce, and Ayers, Travis. Constitutive Models for the Viscoelastic Behavior of Polyimide Membranes at Room and Deep Cryogenic Temperatures.  United States: N. p., 2016. 
Web.  doi:10.13182/FST15-218.

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                    Bhandarkar, Suhas, Betcher, Jacob, Smith, Ryan, Lairson, Bruce, & Ayers, Travis. Constitutive Models for the Viscoelastic Behavior of Polyimide Membranes at Room and Deep Cryogenic Temperatures.  United States.  https://doi.org/10.13182/FST15-218

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                    Bhandarkar, Suhas, Betcher, Jacob, Smith, Ryan, Lairson, Bruce, and Ayers, Travis. Thu .  
"Constitutive Models for the Viscoelastic Behavior of Polyimide Membranes at Room and Deep Cryogenic Temperatures".  United States.  https://doi.org/10.13182/FST15-218.  https://www.osti.gov/servlets/purl/1343043.

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@article{osti_1343043,

  title        = {Constitutive Models for the Viscoelastic Behavior of Polyimide Membranes at Room and Deep Cryogenic Temperatures},

  author       = {Bhandarkar, Suhas and Betcher, Jacob and Smith, Ryan and Lairson, Bruce and Ayers, Travis},

  abstractNote = {Targets for ICF shots on NIF typically use ~500nm thin polyimide films with a coating of 25nm of aluminum as windows that seal the laser entrance hole or LEH. Their role is to contain the hohlraum gas and minimize the extraneous infra-red radiation getting in. This is necessary to precisely control the hohlraum thermal environment for layering inside the capsule with solid deuterium-tritium at 18K. Here, we use our empirical data on the bulging behavior of these foils under various different conditions to develop models to capture the complex viscoelastic behavior of these films at both ambient and cryogenic temperatures. The constitutive equations derived from these models give us the ability to quantitatively specify the film’s behavior during the fielding of these targets and set the best parameters for new target designs.},

  doi          = {10.13182/FST15-218},

  journal      = {Fusion Science and Technology},

  number       = 2,

  volume       = 70,

  place        = {United States},

  year         = {Thu Jun 30 00:00:00 EDT 2016},

  month        = {Thu Jun 30 00:00:00 EDT 2016}

}

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https://doi.org/10.13182/FST15-218

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Works referenced in this record:

Progress toward ignition at the National Ignition Facility
journal, November 2013

Hinkel, D. E.; Edwards, M. J.; Amendt, P. A.
Plasma Physics and Controlled Fusion, Vol. 55, Issue 12
DOI: 10.1088/0741-3335/55/12/124015

Laser Entrance Hole Window Burst and Pressure Deflections at Cryogenic Temperature
journal, January 2011

Lairson, Bruce; Smith, Ryan; Guckian, Jeff
Fusion Science and Technology, Vol. 59, Issue 1
DOI: 10.13182/FST10-3686

Symmetry tuning with megajoule laser pulses at the National Ignition Facility
journal, January 2013

Kline, J. L.; Meezan, N. B.; Callahan, D. A.
EPJ Web of Conferences, Vol. 59
DOI: 10.1051/epjconf/20135902007

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Title: Constitutive Models for the Viscoelastic Behavior of Polyimide Membranes at Room and Deep Cryogenic Temperatures

Abstract

Citation Formats

Progress toward ignition at the National Ignition Facility journal, November 2013

Laser Entrance Hole Window Burst and Pressure Deflections at Cryogenic Temperature journal, January 2011

Symmetry tuning with megajoule laser pulses at the National Ignition Facility journal, January 2013

Progress toward ignition at the National Ignition Facility
journal, November 2013

Laser Entrance Hole Window Burst and Pressure Deflections at Cryogenic Temperature
journal, January 2011

Symmetry tuning with megajoule laser pulses at the National Ignition Facility
journal, January 2013