Atkinson, D P

Baltz, J A

Boehm, K J

Brugman, V P

Coffield, F E

Deis, G A

Edwards, O D

Falabella, S

Fry, J G

Gibson, C R

Haid, B J

Holtmeier, G M

Jedlovec, D R

Locke, S F

Malsbury, T N

Shiromizu, S J

Skulina, K M

Trummer, D J

UNT Digital Library

LLNL-CONF-424163Fabrication and Test of the NIFCryogenic Target SystemT. N. Malsbury, D. P. Atkinson, V. P. Brugman, F. E. Coffield,G. A. Deis, O. D. Edwards, S. Falabella, J. G. Fry, B. J. Haid,G. M. Holtmeier, D. R. Jedlovec, S. F. Locke, S. J. Shiromizu,K. M. Skulina, D. J. Trummer, C. R. Gibson, J. A. Baltz, K. J.BoehmFebruary 19, 201019th Target Fabrication MeetingOrlando, FL, United StatesFebruary 21, 2010 through February 26, 2010Disclaimer  This document was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor Lawrence Livermore National Security, LLC, nor any of their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or Lawrence Livermore National Security, LLC. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or Lawrence Livermore National Security, LLC, and shall not be used for advertising or product endorsement purposes.  Fabrication and Test of the NIF Cryogenic Target SystemPresentation to19th Target Fabrication MeetingFebruary 22, 2010T.N. Malsbury, D.P. Atkinson, V.P. Brugman, F.E. Coffield, G.A. Deis, O.D. Edwards, S. Falabella, J.G. Fry, B.J. Haid, G.M Holtmeier, D.R. Jedlovec, S.F. Locke, S.J. Shiromizu, K.M. Skulina, D.J Trummer – LLNLC.R. Gibson, J.A. Baltz, K.J Boehm – General Atomics2The NIF Cryogenic Target System (CTS) is based on the proven NIF Target Positioner (TARPOS)• Overall design same as presented at last Target Fabrication Meeting—Design based on proven TARPOS architecture• This talk is divided into two parts—Cryogenic Target System— I-TIC on TARPOS3Load, Layer and Characterization System (LLCS)Ignition Target Inserter Cryostat (I-TIC)Target PositionerThe Cryogenic Target System consists of three major sub-systems4The Target Positioner vacuum vessel, support stand and boom are nearly identical to TARPOS• These components used existing designs—Mature, proven hardware—Existing drawings, specifications and vendorsCarbon fiber boomSupport standVacuum vesselBipod supportsThe Target Positioner has completed Acceptance Testing• Controlled movement in all axes— Bipods, boom axis, roll, nod• Demonstrated required vacuum performance— 3x10-6 torrChuck Gibson —19th Target Fabrication Meeting, February 2010 5NIF-0000-00000s2.ppt 6Targets (in containment vessel) enter through  load-lockX-ray sources reside in cupolaThe many functions of the LLCS vacuum vessel required a complex design• LLCS operates in three modes—Glovebox mode for target loading / unloading—Vacuum vessel mode for layering, characterization and shot—Fume hood mode for maintenanceVacuum gloveports (6 total)7The  LLCS Characterization System images the target through the LEH and starburstsVertical translation stage raises x-ray sources to allow boom extensionX-ray beam envelopesThree x-ray sources enclosed in air boxesLLCS X-ray images of capsuleChuck Gibson—19th Target Fabrication Meeting, February 2010 8NIF-0000-00000s2.ppt Vertical axis through LEH Horizontal axis through starburst9Targets are mounted to and cooled by the Ignition Target Inserter Cryostat (I-TIC)Clamshell shroud opens ~5 seconds prior to the shotSumitomo cryocoolerStandard TARPOS boom kinematic mount Thermal inertia deviceIgnition Target Inserter Cryostat (I-TIC) on the TARPOS Target PositonerView of target through shroud  side windowView of target through shroud  top windowI-TIC and Target Alignment System (TAS) at NIF Target Chamber CenterView from CIVS camera at 07-315View from CIVS camera at 90-183Cryogenic target as viewed through I-TIC shroud by NIF Target Alignment SystemChuck Gibson—19th Target Fabrication Meeting, February 2010 15NIF-0000-00000s2.ppt Target Laser Entrance Hole Target Side View06/25/08 NIF-0608-xxxxx.ppt 16Temperature (K)T- time (sec)TT3TT7TT1TT5TT3TT1TT7TT5Begin shroud opening T-10Shot at T-0Temperature Requirement: At shot TT1 & TT3 = 20 ± 0.1 K3 secShroud openNote: Data is logged by ICCS at 1 sample per sec.  Data is represented by the symbol. The dashed lines do not represent data and are included for clarityVibration and Stability measurement system used a cryogenic target and capacitive gauges for measuring X, Y, & Z displacementsTime (hours)Position and temperature of target was measured during cooldown to cryogenic temperature06/25/08 NIF-0608-xxxxx.ppt 1908:43:00 08:43:30 08:44:00-236-235-234-233-232-231-230-229-228-227timeY position (um)08:40:00 08:45:00-260-250-240-230-220-210-200timeY position (um)In Bypass Mode: ± 3µm,  <1 µm rmsITIC on, not in bypass mode: ±30µmITIC is put into bypass mode for a shot at T-30secBypass mode is not being used for target alignmentBypass mode will be required to image ice layers:  requirement ≈ ±1umCryo Target Y(vertical) vibration±3um measuredX-ray imaging requires ≈±1um±30umBypass Mode: turns off the cold head in the ITIC and isolates the ITIC from the cryo-compressor in B582Rendezvous at TCCTarget loaded onto I-TIC but before shrouds are closedRendezvous at TCCTarget after 700 KJ shotSummary and Status• The NIF Cryogenic Target System (CTS) design is based on the proven TARPOS target positioner• The system has been assembled and has successfully completed Acceptance Testing • The system is currently being disassembled and will be moved next month into the NIF Target Bay• The I-TIC performance has been validated by fielding 30 cryogenic targets on NIFChuck Gibson—19th Target Fabrication Meeting, February 2010 22NIF-0000-00000s2.ppt Engineering DRC April 2007– Malsbury-24The challenges of fielding the ignition target• Target must be at cryogenic temperature– Hohlraum ≤ 18 K– Precision of 1 mK– Target base stable ± 1 mK– Target base as low as 7K• Characterization of DT ice surface inside Be or CH shell– X-ray imaging system• Target position– 7 m rms shot time – ≈ +/- 1 m during x-ray characterization• Hazardous materials– Beryllium, Uranium, Tritium in target assemblyCryogenic target assemblyTargetbasetnm 25Target cryostat (ITIC): Maintains required target temperature while preserving target position stabilityThermal capacitance has been designed to provide cooling capacity while cryocooler is off for > 2 minutes….. without it, temperature stability could not be maintained for more than 10 secondsThermal capacitance surrounds 2nd stage of cyrocooler (4K)250 psi He provides thermal capacitance at 4KSumitomo cryocooler1st Stage (<50K)2.5 cm dia copper cold rod (5K)Target in shroudControl heater locationsWarm shield at 293K06/25/08 NIF-0608-xxxxx.ppt 2650mmThis target had a direct view to the shroud windows and caused them to cloudWarm target adapter allows the ITIC to field traditional mag-base targetsTASPOSTARPOSTarget alignment in NIF chamberThe current cryo shot cycle Elapsed hours0Begin cool down6.5Below 40K13.5TARPOS retracted and warm up complete20.0TimeBegin target loading process1 ATM 17.0Shot15.0Laser to target alignment completeBegin gas fill5.0Begin removing spent target3.02821.5TASPOSTARPOSTarget alignment in NIF chamberOn-site target transportation containerTargets warehousedDT Fill StationDT ice layer at spec18.3 K21.0The ignition shot life cycle Elapsed hours0Begin cool down2.0Begin DT fuel transfer9.0TARPOS retracted and warm up complete25.5Time27.0Ready for next targetBegin target loading process0.51 ATM Ice layer formation and X-ray imaging to characterizeMust turn cryo-cooler off to image:  2 min off, 8 min on11.019.7 K24.0Shot23.5Laser to target alignment completetnm 29Cryogenic system are moving towards meeting the requirements for ignitionRequirement Spec Value B490 Test Value Recent NIFMinimum target base temperature ≤ 7K ~4.5 K ~9 KTarget base cooling power at 7K 200 mW 200 mW 200 mWTarget base temperature stability ± 1mK ± 1mK ± 1mKShroud temperature ≤ 100K ≤ 100K ≤ 150KCryocooler duty cycle for imaging2min off / 8min on4 off / 8 onOnly DemostratedOperationCool down time < 6hr 7.5hr 7.5hrTarget Positioning for shot < 7 µm NA20 cryo shots estimate <20 µmPositioning for x-ray imaging < 2 µm p-p NA < 6 µm p-pLEH Condensate < 100nm Est. < 50nm Est. < 50nmThe CryoTARPOS is being integrated now and the system will be moved to NIF early in 2010

Fabrication and Test of the NIF Cryogenic Target System

Fabrication and Test of the NIF Cryogenic Target System

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