Diagnostics Implemented on NIF


X-ray | Optical | Nuclear


Nuclear

Diagnostic acronym Diangostic  Port location Built and commisioned by  Description of function  Published references 
EMP Electromagnetic Power 102-84 LLNL EMP measures the electromagnetic frequency spectrum in the target chamber. C. G. Brown et al., “Analysis of Electromagnetic Pulse (EMP) Measurements in the National Ingition Facility's Target Bay and Chamber.”  International Fusion Science and Applications (IFSA) Bordeaux, France, September 12, 2011,  LLNL-PROC-512731 
GRH Time and spectrally-resolved Gamma Reaction History 64, 20 LANL, LLNL GRH measures the spectrum and time history of the emission of target produced gamma rays using four spectral channels (typically 2.9, 5, 8, and 10 MeV). In each GRH channel, gammas interact with a foil to produce Compton electrons, which recoil into a gas-filled cell generating broadband Cerenkov light (from 250 to 700 nm) if their velocity exceeds the local speed of light as determined by the type and pressure of the gas in the cell. For each channel, Cerenkov light is relayed to a high-speed detector using an off-axis parabolic mirror. In ignition related experiments using DT gas, GRH is used to measure the absolute level of DT gamma-ray emission and to determine the amount of ablator remaining in the compressed capsule through observation of gamma rays from the interaction of the fusion neutrons with the carbon shell. Robert M. Malone et al., “Overview of the gamma reaction history diagnostic for the National Ignition Facility (NIF).” Proc. SPIE. 7652, International Optical Design Conference 2010, 76520Z. (July 01, 2010)

D.C. Wilson et al., “Diagnosing ignition with DT reaction history,” Rev. Sci. Instrum. 79, 10E525 (2008).
A.M. McEvoy et al., “Gamma bang time analysis at OMEGA,” Rev. Sci. Instrum. 81,10D322 (2010).

N.M. Hoffman et al., “Using gamma-rayemission to measure areal density of inertialconfinement fusion capsules,” Rev. Sci.Instrum. 81, 10D332 (2010).

H.W. Herrmann et al., “Diagnosing inertial confinement fusion gamma ray physics,”Rev. Sci. Instrum. 81, 10D333 (2010).

D.B. Sayre et al., “Multi-shot analysis of thegamma reaction history diagnostic,” Rev.Sci. Instrum. 83, 10D905 (2012).
MRS Magnetic Recoil Spectrometer  77,324 With use of DIM appendage  MIT, LLE, LLNL MRS is a neutron spectrometer typically used in yield experiments to infer the neutron energy spectra. Neutrons interact with a plastic foil held 30 cm from the target, producing knock-on protons or deuterons. These charged particles are then energy dispersed by their momentum in a magnetic field and focused on an array of solid plastic film track detectors (CR-39) located at the focal point of the spectrometer. After a shot, the CR-39 film is removed and etched and the neutron spectrum (neutrons as a function of their energy) and yield (total number of neutrons) are determined by the location and number of tracks on the detector films. Ion temperature is also recorded with lower resolution than the NTOF, dependent on the thickness of the plastic foil. J.A. Frenje et al., “Probing high areal-density cryogenic deuterium-tritium implosions using downscattered neutron spectra measured by the magnetic recoil spectrometer,” Physics of Plasmas 17, 056311 (2010).

                                                   
D.T. Casey et al., “The coincidence counting technique for orders of magnitude background reduction in data obtained with the magnetic recoil spectrometer at OMEGA and the NIF,” Rev. Sci. Instrum. 82, 073502 (2011).


D.T. Casey et al., “Measuring the absolute deuterium–tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF,” Rev. Sci. Instrum. 83, 10D912 (2012).


M. Gatu Johnson et al., “Neutron spectrometry—An essential tool for diagnosing implosions at the National Ignition Facility,”Rev. Sci. Instrum. 83, 10D308 (2012).
Mag-PTOF  Magnetic - Particle Time­of-Flight Proton Detector DIM Appendage MIT, LLE, LLNL
H. G. Rinderknecht., “A magnetic particle time-of-flight (MagPTOF) diagnostic for measurements of shock- and compression-bang time at the NIF.”  Rev. Sci. Instrum. 85, 11D901 (2014)
NAD (Thulium) Neutron Activation Detector DIM Appendage LANL, LLNL The Neutron Activation Diagnostics (NADs) measure the integrated neutron yield of a target capsule by activating a sample material, removing it from the chamber, and determining the activation level using nuclear counting techniques.  The Thulium NAD is a neutron activation diagnostic sample specifically for measuring neutrons with energies higher than the DT primary neutrons.  It requires specialized gamma counting capability to analyze.  
NAD—WRF mount Neutron Activation Detector DIM Appendage LLNL The Neutron Activation Diagnostics (NADs) measure the integrated neutron yield of a target capsule by activating a sample material, removing it from the chamber, and determining the activation level using nuclear counting techniques.   The WRF mount package places the samples very near the target.  An indium (In) sample material is often used in this configuration to measure low energy DD neutrons.  
NAD Cu (20M) Neutron Activation Detector 116,316 SNL, LLNL The Neutron Activation Diagnostics (NADs) measure the integrated neutron yield of a target capsule by activating a sample material, removing it from the chamber, and determining the activation level using nuclear counting techniques.   The NAD Cu (20m) measures the neutron yield from a DT-filled capsule by activating a copper foil in a neutron line-of-sight in the neutron alcove. Because the decay rate of the activated Cu is short (9.7 m), the foil must be removed rapidly and counted in a nearby detector system. G. W. Cooper et al., “Copper activation deuterium-tritium neutron yield measurements at the National Ignition Facility,” Rev. Sci. Instrum.  83, 10D918 (2012)
NAD Zr (Flange) Neutron Activation Detector 20 Fixed locations LLNL The Neutron Activation Diagnostics (NADs) measure the integrated neutron yield of a target capsule by activating a sample material, removing it from the chamber, and determining the activation level using nuclear counting techniques.   The Flange NAD uses a set of up to 20 Zr activation samples strategically mounted on the flanges of the target chamber. The three-day half-life of the Zr activation product allows the samples to be counted off of the NIF site. The suite of Zr NADs measures the anisotropy (lack of uniformity in all directions) of neutron yield from the target. If the angular distribution is not isotropic, a variation in yield as a function of direction indicates a variation or asymmetry in the fuel areal density.  D.L. Bleuel et al., “Neutron activation diagnostics at the National Ignition Facility,” Rev. Sci. Instrum. 83, 10D313 (2012).
NAD Zr  (well) Neutron Activation Detector Fixed LLE, LLNL The Neutron Activation Diagnostics (NADs) measure the integrated neutron yield of a target capsule by activating a sample material, removing it from the chamber, and determining the activation level using nuclear counting techniques.  The Well NAD uses activation of a single Zr sample inserted into a well on the NIF target chamber.   The three-day half-life of the Zr activation product allows the samples to be counted off of the NIF site. D.L. Bleuel et al., “Neutron activation diagnostics at the National Ignition Facility,” Rev. Sci. Instrum. 83, 10D313 (2012).
C.B. Yeamans et al., Enhanced NIF neutron activation diagnositc, "Rev. Sci. Instrum 83, 10D315 (2012)
NIS Neutron Imager System 93-315 (With use of DIM) LANL, LLNL NIS measures static neutron images of the primary (14 MeV) and the down scattered (6–12 MeV) neutrons from a burning DT capsule. The hot spot size and fuel asym­metry are determined from the image of the primary neutrons, and the cold fuel areal density is inferred from the down scattered ratio. F. E. Merrill, et Al., “The neutron imaging diagnostic at NIF,” Rev. Sci. Instrum. 83, 10D317 (2012)
Mark D. Wilke, et al., “The National Ignition Facility Neutron Imaging System,” Rev. Sci. Instrum. 79, 10E529 (2008)

P. Volegov, et al., “Neutron source reconstruction from pinhole imaging at National Ignition Facility,” Rev. Sci. Instrum. 85, 023508 (2014)

D. C. Wilson, et al., “Modeling the National Ignition Facility neutron imaging system,” Rev. Sci. Instrum. 81, 10D335 (2010)

E.N. Loomis et al., “Progress toward the development and testing of source reconstruction methods for NIF neutron imaging,” Rev. Sci. Instrum. 81, 10D311 (2010).
NITOF Neutron Imager Time-of-Flight 93-315 (With use of DIM) LANL, LLNL NITOF measures neutron yield, ion temperature, and areal density along the NIS line of sight.  It is essentially the same as the other neutron time-of-flight diagnostics in concept. As it is the furthest from TCC, it has the highest spectral resolution amount the nTOFs, but because it usually has Neutron imager or Visar hardware along its LOS, it is more difficult to maintain calibration. G.P. Grim et al., “A spatially resolved ion temperature diagnostic for the National Ignition Facility,” Rev. Sci. Instrum. 79, 10E537 (2008).
NTOF20 IgHi Neutron Time-of-Flight 116,316 LLE, LLNL NTOF detectors measure the time-of-flight of neutrons emitted from the target. The arrival time at the detector provides the neutron energy, and the spread of arrival times is related to the ion temperature. The NTOF20IgHi is a CVD-based synthetic diamond detector located in the neutron alcove about 20 meters from TCC. Its main function is to measure ion temperature of the hot spot in an ignition target. V. Yu et al., “The National Ignition Facility neutron time-of-flight system and its initial performance,” Rev. Sci. Instrum. 81, 10D325 (2010).

R.A. Lerche et al., “National Ignition Facility neutron time-of-flight measurements,” Rev. Sci. Instrum. 81, 10D319 (2010).
NTOF 4.5 BT
NTOF DTHi
NTOF DTLo		 Neutron Time-of-Flight 64-136
64-309
64-330		 LLE, LLNL NTOF detectors measure the time-of-flight of neutrons emitted from the target. There are 3 NTOFs located at a distance of 4.5 m from TCC used to measure neutron yield, ion temperature, and neutron bang time for experiments with yields of 1E10 – 1E13 neutrons from TCC. V. Yu et al., “The National Ignition Facility neutron time-of-flight system and its initial performance,” Rev. Sci. Instrum. 81, 10D325 (2010).

R.A. Lerche et al., “National Ignition Facility neutron time-of-flight measurements,” Rev. Sci. Instrum. 81, 10D319 (2010).
NTOF20 SPEC-A
NTOF20 SPEC-E
NTOF 18M-SP		 Neutron Time-of-Flight 90-174
116-316
161-156		 LLE, LLNL NTOF detectors measure the time-of-flight of neutrons emitted from the target. Three NTOFs located at a distances of 18-20 m (alcove/equatorial) from TCC are used to measure neutron yield, ion temperature, and areal density.  V. Yu et al., “The National Ignition Facility neutron time-of-flight system and its initial performance,” Rev. Sci. Instrum. 81, 10D325 (2010).

R.A. Lerche et al., “National Ignition Facility neutron time-of-flight measurements,” Rev. Sci. Instrum. 81, 10D319 (2010).
PTOF  Particle Time­of-Flight Proton Detector DIM Appendage 90-78 only MIT, LLE, LLNL Some implosions on NIF have a gas fill of deuterium (D) and helium-3 (3He) in order to produce 14.5 MeV protons from the D3He fusion reaction. The emission time of the protons is measured with a synthetic diamond wafer detector made by the chemical vapor deposition (CVD) technique. Despite the relatively slow flight time of the protons compared to x-rays, the background from hohl­raum x-rays is a problem for this diagnostic. Efforts are underway to reduce this background. H. Rinderknect et al., “A novel particle time of flight diagnostic for measurements of shock- and compression-bang times in D3He and DT implosions at the NIF,” Rev. Sci. Instrum. 83, 10D902 (2012).
RAGS Radiochemistry Analysis of Gase­ous Samples 180, 0 Fixed  SNL, LLNL RAGS is used to collect and measure neutron activation products that are gaseous at room temperature. For ex­ample, noble gases such as Kr and Xe can be used as ac­tivation detectors by pre-loading low-levels into the abla­tor. The resulting Kr and/or Xe isotopes produced can be collected and chemically fractionated very efficiently by cryogenic trapping. Isotopic analysis of the collected samples, when corrected for contributions from air, can be used to obtain quantitative data on multiple capsule performance parameters such as mix of the shell mate­rial into the fuel, asymmetry of implosion, shell and fuel areal density at peak emission, and neutron yield. G.P. Grim et al., “Prompt radiochemistry at the National Ignition Facility,” Rev. Sci. Instrum. 79, 10E503 (2008).

S.L. Nelson et al., “RAGS: The Gaseous Sample Collection Diagnostic at the National Ignition Facility,” IEEE Transactions on Plasma Science 39 (8) (2011).

M.A. Stoyer et al., “Collection of solid and gaseous samples to diagnose inertial confinement fusion implosions,” Rev. Sci. Instrum. 83, 023505 (2012).
SRC Solid Radiochemical Collection Diagnostic DIM Appendage LLNL Bulk target materials as well as trace elements in the targets can be activated by neutrons or possibly even charged particles to produced radioactive species. SRC units placed about 50 centimeters from TCC are used to collect the solid debris coming from the target, which may contain some of these radioactive species. The SRC units are removed postshot, and the presence of radioactive isotopes is determined by nuclear counting techniques in facilities off of the NIF site. Using this technique, radioactive gold isotopes resulting from activation of the target hohlraums have been detected. M.A. Stoyer et al., “Collection of solid and gaseous samples to diagnose inertial confinement fusion implosions,” Rev. Sci. Instrum. 83, 023505 (2012).
TOAD TOAD Solid Radiochem­ical Collection Diagnostic DIM Appendage LLNL TOAD is a specialized sample holder for holding potentially radioactive or hazardous samples in the Solid Rad Chem (SRC) diagnostic package.  It allows for simplified handling.  It has been used for depleted Uranium samples. Narek Gharibyan et al., “First fission yield measurements at the National Ignition Facility 14-MeV neutron fission of 238U.”  J Radioanal Nucl Chem (2015) 303:1335–1338
SPBT  South Pole Bang Time Neutron Channel Uses port 161, 146 records on the LOS of 0-180 LLE, LLNL The SPBT Neutron Channel measures through the lower LEH the time of peak x-ray emission (peak compression) relative to the laser pulse. D.H. Edgell et al., “South pole bang-time diagnostic on the National Ignition Facility,” Rev. Sci. Instrum. 83, 10E119 (2012). 
WRF Wedge Range Filter DIM Appendage MIT, LLE, LLNL WRFs are used for D3He gas-filled implosions. The escap­ing thermonuclear protons lose energy in the compressed plastic. The energy spectrum of the escaping protons is measured by passing them through a wedge of material and measuring the energy of the protons after passing through various parts of the wedge with CR-39 track detectors. These WRF units are mounted at about 50 cm from TCC. The technique yields valuable data prior to the full compression of ablator. When the density of the ablator is about 200 mg/cm2or higher, the protons are stopped in the ablator. A.B. Zylstra et al., “Charged-particle spectroscopy for diagnosing shock ρR and strength in NIF implosions,” Rev. Sci. Instrum. 83, 10D901 (2012).

 

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