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Oct 2012

Volume 83, Issue 10, Articles (10xxxx)

Issue Cover Spotlight Figure

Rev. Sci. Instrum. 83, 101301 (2012); http://dx.doi.org/10.1063/1.4750234 (26 pages)

N. L. Kugland, D. D. Ryutov, C. Plechaty, J. S. Ross, and H.-S. Park

Proton imaging is widely used to reveal electric and magnetic field structures in high energy density plasmas. Even for smooth parent structures, strongly deflected protons can form images with strange shapes or singular lines of very high intensity (i.e. caustics).

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back to top Fusion Products and Fast Ions I—Ramon J. Leeper, Session Chairman

Ultra-high speed photomultiplier tubes with nanosecond gating for fusion diagnostics

J. S. Milnes, C. J. Horsfield, M. S. Rubery, V. Yu. Glebov, and H. W. Herrmann

Rev. Sci. Instrum. 83, 10D301 (2012); http://dx.doi.org/10.1063/1.4728313 (3 pages)

Online Publication Date: 5 June 2012

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Fusion diagnostics can involve the measurement of ultra-fast optical pulses, often in close temporal proximity. We present a solution for the diagnostics of gamma reaction history and neutron time of flight by using microchannel plate based photomultiplier tubes (PMTs). The time response of the PMTs can be as fast as 100 ps FWHM and with a gain of up to 107. To observe small events in close temporal proximity to much larger signals such as the down-scattered fraction, the response of MCP-PMTs can be gated with an on/off ratio of up to 1013 in just 2 ns.
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52.70.Kz Optical (ultraviolet, visible, infrared) measurements
42.79.-e Optical elements, devices, and systems
85.60.Ha Photomultipliers; phototubes and photocathodes

Time-resolved ion energy distribution measurements using an advanced neutral particle analyzer on the MST reversed-field pinch

S. Eilerman, J. K. Anderson, J. A. Reusch, D. Liu, G. Fiksel, S. Polosatkin, and V. Belykh

Rev. Sci. Instrum. 83, 10D302 (2012); http://dx.doi.org/10.1063/1.4728312 (3 pages) | Cited 4 times

Online Publication Date: 8 June 2012

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An advanced neutral particle analyzer (ANPA) capable of simultaneously measuring hydrogen and deuterium ions of energies up to 45 keV has recently been developed for use on the Madison Symmetric Torus. The charge-to-mass separation allows for separate analysis of bulk deuterium ions and hydrogen ions injected with a 1 MW, 25 keV neutral beam. Orientation of the ANPA allows sampling of different regions of ion velocity space; a radial viewport favors collection of ions with high v⊥/|v| while a recently installed tangential viewport favors ions with high v||/|v|, such as those from the core-localized fast ion population created by the neutral beam. Signals are observed in the ANPA's highest energy channels during periodic magnetic reconnection events, which are drivers of anisotropic, non-Maxwellian ion energization in the reversed-field pinch. ANPA signal strength is dependent on the background neutral density, which also increases during magnetic reconnection events, so careful analysis must be performed to identify the true change in the ion distribution. A Monte Carlo neutral particle tracing code (NENE) is used to reconstruct neutral density profiles based on Dα line emission, which is measured using a 16-chord filtered photodiode array.
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52.58.Lq Z-pinches, plasma focus, and other pinch devices
52.70.Nc Particle measurements
52.20.Hv Atomic, molecular, ion, and heavy-particle collisions
52.50.Gj Plasma heating by particle beams
52.30.Cv Magnetohydrodynamics (including electron magnetohydrodynamics)

Development of the prototype pneumatic transfer system for ITER neutron activation system

M. S. Cheon, C. R. Seon, S. Pak, H. G. Lee, and L. Bertalot

Rev. Sci. Instrum. 83, 10D303 (2012); http://dx.doi.org/10.1063/1.4729673 (3 pages)

Online Publication Date: 20 June 2012

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The neutron activation system (NAS) measures neutron fluence at the first wall and the total neutron flux from the ITER plasma, providing evaluation of the fusion power for all operational phases. The pneumatic transfer system (PTS) is one of the key components of the NAS for the proper operation of the system, playing a role of transferring encapsulated samples between the capsule loading machine, irradiation stations, counting stations, and disposal bin. For the validation and the optimization of the design, a prototype of the PTS was developed and capsule transfer tests were performed with the developed system.
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52.55.Fa Tokamaks, spherical tokamaks
52.40.Hf Plasma-material interactions; boundary layer effects
52.70.Nc Particle measurements

Compact solid-state neutral particle analyzer in current mode

Y. B. Zhu, A. Bortolon, W. W. Heidbrink, S. L. Celle, and A. L. Roquemore

Rev. Sci. Instrum. 83, 10D304 (2012); http://dx.doi.org/10.1063/1.4732070 (3 pages)

Online Publication Date: 5 July 2012

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Solid state neutral particle analyzer (ssNPA) arrays are operated in current mode on the DIII-D tokamak and the National Spherical Torus Experiment (NSTX). Compared with conventional pulse-counting NPAs, current-mode operation sacrifices energy resolution to obtain economical, high-bandwidth, pitch-angle resolved measurements. With the success from a new three-channel near-vertical-view current mode ssNPA on DIII-D, the apertures on an existing array on NSTX were expanded to increase the particle influx. The sightlines of both arrays intersect heating beams, enabling both active and passive charge exchange measurements. The spatial resolution at beam intersection is typically 5 cm on both devices. Directly deposited ultra-thin foils on the detector surface block stray photons below the energy of 1 keV and also set low energy threshold about 25 keV for deuterium particle detection. Oscillations in neutral flux produced by high frequency magnetohydrodynamics (MHD) instabilities are readily detected.
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07.77.Ka Charged-particle beam sources and detectors
29.40.-n Radiation detectors

Initial measurements of fast ion loss in KSTAR

Junghee Kim, Jun Young Kim, S. W. Yoon, M. García-Muñoz, M. Isobe, and W. C. Kim

Rev. Sci. Instrum. 83, 10D305 (2012); http://dx.doi.org/10.1063/1.4733550 (3 pages)

Online Publication Date: 13 July 2012

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A fast ion loss detector (FILD) has been installed and tested in Korea Superconducting Tokamak Advanced Research (KSTAR). KSTAR FILD measures the energy and the pitch-angle of the escaping ions with the striking positions on the scintillator plane. Measurements of the fast ion loss have been performed for the neutral beam heated plasmas. Initial experimental results indicate the prompt losses from neutral beam are dominant and the effects of the resonant magnetic perturbation on the fast ion loss are investigated. In addition, further design change of the detector-head in order to avoid excessive heat load and to detect the fusion products or the fast ions having order of MeV of energy is also discussed.
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52.55.Fa Tokamaks, spherical tokamaks
52.50.Gj Plasma heating by particle beams
52.70.-m Plasma diagnostic techniques and instrumentation

Investigating the performance of an ion luminescence probe as a multichannel fast-ion energy spectrometer using pulse height analysis

B. Zurro, A. Baciero, D. Jiménez-Rey, L. Rodríguez-Barquero, and M. T. Crespo

Rev. Sci. Instrum. 83, 10D306 (2012); http://dx.doi.org/10.1063/1.4733572 (3 pages)

Online Publication Date: 13 July 2012

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We investigate the capability of a fast-ion luminescent probe to operate as a pulse height ion energy analyzer. An existing high sensitivity system has been reconfigured as a single channel ion detector with an amplifier to give a bandwidth comparable to the phosphor response time. A digital pulse processing method has been developed to determine pulse heights from the detector signal so as to obtain time-resolved information on the ion energy distribution of the plasma ions lost to the wall of the TJ-II stellarator. Finally, the potential of this approach for magnetic confined fusion plasmas is evaluated by studying representative TJ-II discharges.
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52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.55.Jd Magnetic mirrors, gas dynamic traps
29.40.-n Radiation detectors

X-ray bang-time and fusion reaction history at picosecond resolution using RadOptic detection

S. P. Vernon, M. E. Lowry, K. L. Baker, C. V. Bennett, J. R. Celeste, C. Cerjan, S. Haynes, V. J. Hernandez, W. W. Hsing, G. A. LaCaille, R. A. London, B. Moran, A. Schach von Wittenau, P. T. Steele, and R. E. Stewart

Rev. Sci. Instrum. 83, 10D307 (2012); http://dx.doi.org/10.1063/1.4729677 (3 pages) | Cited 1 time

Online Publication Date: 16 July 2012

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We report recent progress in the development of RadOptic detectors, radiation to optical converters, that rely upon x-ray absorption induced modulation of the optical refractive index of a semiconductor sensor medium to amplitude modulate an optical probe beam. The sensor temporal response is determined by the dynamics of the electron-hole pair creation and subsequent relaxation in the sensor medium. Response times of a few ps have been demonstrated in a series of experiments conducted at the LLNL Jupiter Laser Facility (JLF). This technology will enable x-ray bang-time and fusion burn-history measurements with ∼ ps resolution.
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29.40.Wk Solid-state detectors
07.85.Fv X- and γ-ray sources, mirrors, gratings, and detectors

Neutron spectrometry—An essential tool for diagnosing implosions at the National Ignition Facility (invited)

M. Gatu Johnson, J. A. Frenje, D. T. Casey, C. K. Li, F. H. Séguin, R. Petrasso, R. Ashabranner, R. M. Bionta, D. L. Bleuel, E. J. Bond, J. A. Caggiano, A. Carpenter, C. J. Cerjan, T. J. Clancy, T. Doeppner, et al.

Rev. Sci. Instrum. 83, 10D308 (2012); http://dx.doi.org/10.1063/1.4728095 (6 pages) | Cited 9 times

Online Publication Date: 30 July 2012

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DT neutron yield (Yn), ion temperature (Ti), and down-scatter ratio (dsr) determined from measured neutron spectra are essential metrics for diagnosing the performance of inertial confinement fusion (ICF) implosions at the National Ignition Facility (NIF). A suite of neutron-time-of-flight (nTOF) spectrometers and a magnetic recoil spectrometer (MRS) have been implemented in different locations around the NIF target chamber, providing good implosion coverage and the complementarity required for reliable measurements of Yn, Ti, and dsr. From the measured dsr value, an areal density (ρR) is determined through the relationship ρRtot (g/cm2) = (20.4 ± 0.6) × dsr10-12 MeV. The proportionality constant is determined considering implosion geometry, neutron attenuation, and energy range used for the dsr measurement. To ensure high accuracy in the measurements, a series of commissioning experiments using exploding pushers have been used for in situ calibration of the as-built spectrometers, which are now performing to the required accuracy. Recent data obtained with the MRS and nTOFs indicate that the implosion performance of cryogenically layered DT implosions, characterized by the experimental ignition threshold factor (ITFx), which is a function of dsr (or fuel ρR) and Yn, has improved almost two orders of magnitude since the first shot in September, 2010.
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28.52.Lf Components and instrumentation
28.52.Cx Fueling, heating and ignition
52.70.Nc Particle measurements
52.57.-z Laser inertial confinement
52.25.-b Plasma properties
29.30.Hs Neutron spectroscopy

Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA

V. Yu. Glebov, C. Forrest, J. P. Knauer, A. Pruyne, M. Romanofsky, T. C. Sangster, M. J. Shoup, III, C. Stoeckl, J. A. Caggiano, M. L. Carman, T. J. Clancy, R. Hatarik, J. McNaney, and N. P. Zaitseva

Rev. Sci. Instrum. 83, 10D309 (2012); http://dx.doi.org/10.1063/1.4731001 (3 pages) | Cited 1 time

Online Publication Date: 30 July 2012

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A new neutron time-of-flight (nTOF) detector with a bibenzyl crystal as a scintillator has been designed and manufactured for the National Ignition Facility (NIF). This detector will replace a nTOF20-Spec detector with an oxygenated xylene scintillator currently operational on the NIF to improve the areal-density measurements. In addition to areal density, the bibenzyl detector will measure the D–D and D–T neutron yield and the ion temperature of indirect- and direct-drive-implosion experiments. The design of the bibenzyl detector and results of tests on the OMEGA Laser System are presented.
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29.40.Mc Scintillation detectors
29.30.-h Spectrometers and spectroscopic techniques
52.57.Kk Fast ignition of compressed fusion fuels
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Comparisons of NIF convergent ablation simulations with radiograph data

R. E. Olson, D. G. Hicks, N. B. Meezan, J. A. Koch, and O. L. Landen

Rev. Sci. Instrum. 83, 10D310 (2012); http://dx.doi.org/10.1063/1.4738653 (3 pages) | Cited 2 times

Online Publication Date: 6 August 2012

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A technique for comparing simulation results directly with radiograph data from backlit capsule implosion experiments will be discussed. Forward Abel transforms are applied to the kappa*rho profiles of the simulation. These provide the transmission ratio (optical depth) profiles of the simulation. Gaussian and top hat blurs are applied to the simulated transmission ratio profiles in order to account for the motion blurring and imaging slit resolution of the experimental measurement. Comparisons between the simulated transmission ratios and the radiograph data lineouts are iterated until a reasonable backlighter profile is obtained. This backlighter profile is combined with the blurred, simulated transmission ratios to obtain simulated intensity profiles that can be directly compared with the radiograph data. Examples will be shown from recent convergent ablation (backlit implosion) experiments at the NIF.
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42.30.Va Image forming and processing

Gamma-to-electron magnetic spectrometer (GEMS): An energy-resolved γ-ray diagnostic for the National Ignition Facility

Y. Kim, H. W. Herrmann, T. J. Hilsabeck, K. Moy, W. Stoeffl, J. M. Mack, C. S. Young, W. Wu, D. B. Barlow, J. B. Schillig, J. R. Sims, Jr., F. E. Lopez, D. Mares, J. A. Oertel, and A. C. Hayes-Sterbenz

Rev. Sci. Instrum. 83, 10D311 (2012); http://dx.doi.org/10.1063/1.4738650 (3 pages)

Online Publication Date: 8 August 2012

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The gamma-to-electron magnetic spectrometer, having better than 5% energy resolution, is proposed to resolve γ-rays in the range of Eo ± 20% in single shot, where Eo is the central energy and is tunable from 2 to 25 MeV. Gamma-rays from inertial confinement fusion implosions interact with a thin Compton converter (e.g., beryllium) located at approximately 300 cm from the target chamber center (TCC). Scattered electrons out of the Compton converter enter an electromagnet placed outside the NIF chamber (approximately 600 cm from TCC) where energy selection takes place. The electromagnet provides tunable Eo over a broad range in a compact manner. Energy resolved electrons are measured by an array of quartz Cherenkov converters coupled to photomultipliers. Given 100 detectable electrons in the energy bins of interest, 3 × 1014 minimum deuterium/tritium (DT) neutrons will be required to measure the 4.44 MeV 12C γ-rays assuming 200 mg/cm2 plastic ablator areal density and 3 × 1015 minimum DT neutrons to measure the 16.75 MeV DT γ-ray line.
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07.81.+a Electron and ion spectrometers
07.85.Nc X-ray and γ-ray spectrometers

Deuterium–tritium neutron yield measurements with the 4.5 m neutron-time-of-flight detectors at NIF

M. J. Moran, E. J. Bond, T. J. Clancy, M. J. Eckart, H. Y. Khater, and V. Yu. Glebov

Rev. Sci. Instrum. 83, 10D312 (2012); http://dx.doi.org/10.1063/1.4739077 (3 pages) | Cited 1 time

Online Publication Date: 8 August 2012

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The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator/photodetector neutron-time-of-flight (nTOF) detectors for measuring deuterium–deuterium (DD) and DT neutron yields. The detectors provided consistent neutron yield (Yn) measurements from below 109 (DD) to nearly 1015 (DT). The detectors initially demonstrated detector-to-detector Yn precisions better than 5%, but lacked in situ absolute calibrations. Recent experiments at NIF now have provided in situ DT yield calibration data that establish the absolute sensitivity of the 4.5 m differential tissue harmonic imaging (DTHI) detector with an accuracy of ±10% and precision of ±1%. The 4.5 m nTOF calibration measurements also have helped to establish improved detector impulse response functions and data analysis methods, which have contributed to improving the accuracy of the Yn measurements. These advances have also helped to extend the usefulness of nTOF measurements of ion temperature and downscattered neutron ratio (neutron yield 10–12 MeV divided by yield 13–15 MeV) with other nTOF detectors.
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52.57.-z Laser inertial confinement
28.52.-s Fusion reactors

Neutron activation diagnostics at the National Ignition Facility (invited)

D. L. Bleuel, C. B. Yeamans, L. A. Bernstein, R. M. Bionta, J. A. Caggiano, D. T. Casey, G. W. Cooper, O. B. Drury, J. A. Frenje, C. A. Hagmann, R. Hatarik, J. P. Knauer, M. Gatu Johnson, K. M. Knittel, R. J. Leeper, et al.

Rev. Sci. Instrum. 83, 10D313 (2012); http://dx.doi.org/10.1063/1.4733741 (5 pages) | Cited 1 time

Online Publication Date: 9 August 2012

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Neutron yields are measured at the National Ignition Facility (NIF) by an extensive suite of neutron activation diagnostics. Neutrons interact with materials whose reaction cross sections threshold just below the fusion neutron production energy, providing an accurate measure of primary unscattered neutrons without contribution from lower-energy scattered neutrons. Indium samples are mounted on diagnostic instrument manipulators in the NIF target chamber, 25–50 cm from the source, to measure 2.45 MeV deuterium-deuterium fusion neutrons through the 115In(n,n’)115m In reaction. Outside the chamber, zirconium and copper are used to measure 14 MeV deuterium-tritium fusion neutrons via 90Zr(n,2n), 63Cu(n,2n), and 65Cu(n,2n) reactions. An array of 16 zirconium samples are located on port covers around the chamber to measure relative yield anisotropies, providing a global map of fuel areal density variation. Neutron yields are routinely measured with activation to an accuracy of 7% and are in excellent agreement both with each other and with neutron time-of-flight and magnetic recoil spectrometer measurements. Relative areal density anisotropies can be measured to a precision of less than 3%. These measurements reveal apparent bulk fuel velocities as high as 200 km/s in addition to large areal density variations between the pole and equator of the compressed fuel.
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52.70.Nc Particle measurements
28.52.Lf Components and instrumentation
28.52.Fa Materials
29.25.Dz Neutron sources
52.25.Tx Emission, absorption, and scattering of particles
82.80.Jp Activation analysis and other radiochemical methods

Exploration of ion temperature profile measurements at JET using the upgraded neutron profile monitor

D. Marocco, B. Esposito, M. Riva, and JET-EFDA Contributors

Rev. Sci. Instrum. 83, 10D314 (2012); http://dx.doi.org/10.1063/1.4734040 (3 pages)

Online Publication Date: 15 August 2012

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The neutron profile monitor (NPM), routinely used at the Joint European Torus for neutron emissivity profile measurements, consists of two fan-shaped arrays of collimators and each line of sight (LOS) is equipped with a NE213 liquid organic scintillator for simultaneous measurements of the 2.5 MeV and 14 MeV neutrons. A digital system developed in ENEA has replaced the analog acquisition electronics and now enables the NPM to perform spatially resolved neutron spectrometry by providing neutron pulse height spectra (PHS) for each LOS. However, the NPM was not originally designed as a spectrometer and, therefore, lacks several key features, such as detailed measurements of the detector response functions and the presence of detector stability monitors. We present a proof of principle of ion temperature profile measurements derived from the NPM PHS in high plasma current discharges using simulated detector response functions.
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52.25.Os Emission, absorption, and scattering of electromagnetic radiation
52.55.Fa Tokamaks, spherical tokamaks
52.70.Nc Particle measurements
29.30.Hs Neutron spectroscopy
29.40.Mc Scintillation detectors
52.25.Fi Transport properties

Enhanced NIF neutron activation diagnostics

C. B. Yeamans, D. L. Bleuel, and L. A. Bernstein

Rev. Sci. Instrum. 83, 10D315 (2012); http://dx.doi.org/10.1063/1.4739230 (3 pages) | Cited 1 time

Online Publication Date: 16 August 2012

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The NIF neutron activation diagnostic suite relies on removable activation samples, leading to operational inefficiencies and a fundamental lower limit on the half-life of the activated product that can be observed. A neutron diagnostic system measuring activation of permanently installed samples could remove these limitations and significantly enhance overall neutron diagnostic capabilities. The physics and engineering aspects of two proposed systems are considered: one measuring the 89Zr/89mZr isomer ratio in the existing Zr activation medium and the other using potassium zirconate as the activation medium. Both proposed systems could improve the signal-to-noise ratio of the current system by at least a factor of 5 and would allow independent measurement of fusion core velocity and fuel areal density.
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52.57.Bc Target design and fabrication
52.70.Nc Particle measurements
28.52.Fa Materials

Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments

N. Guler, P. Volegov, C. R. Danly, G. P. Grim, F. E. Merrill, and C. H. Wilde

Rev. Sci. Instrum. 83, 10D316 (2012); http://dx.doi.org/10.1063/1.4746745 (3 pages)

Online Publication Date: 22 August 2012

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Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13–17 MeV) and down-scattered (6–12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.
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28.52.Av Theory, design, and computerized simulation
28.52.Cx Fueling, heating and ignition
29.25.Dz Neutron sources
52.57.-z Laser inertial confinement

The neutron imaging diagnostic at NIF (invited)

F. E. Merrill, D. Bower, R. Buckles, D. D. Clark, C. R. Danly, O. B. Drury, J. M. Dzenitis, V. E. Fatherley, D. N. Fittinghoff, R. Gallegos, G. P. Grim, N. Guler, E. N. Loomis, S. Lutz, R. M. Malone, et al.

Rev. Sci. Instrum. 83, 10D317 (2012); http://dx.doi.org/10.1063/1.4739242 (6 pages) | Cited 7 times

Online Publication Date: 23 August 2012

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A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6–12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.
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28.52.Cx Fueling, heating and ignition
29.25.Dz Neutron sources
29.40.-n Radiation detectors
52.70.Nc Particle measurements

First fusion proton measurements in TEXTOR plasmas using activation technique

G. Bonheure, J. Mlynar, G. Van Wassenhove, M. Hult, R. González de Orduña, G. Lutter, P. Vermaercke, A. Huber, B. Schweer, G. Esser, and W. Biel

Rev. Sci. Instrum. 83, 10D318 (2012); http://dx.doi.org/10.1063/1.4739228 (3 pages)

Online Publication Date: 29 August 2012

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MeV particle loss measurements from fusion plasmas, in particular alpha particles, remain difficult in large fusion devices and further R&D is needed for ITER. This paper describes the first attempt to measure 3 MeV escaping fusion protons emitted from TEXTOR tokamak plasmas using activation technique. This technique was successfully demonstrated, initially, in 2006 on the JET tokamak. An ion camera equipped with a collimator and several types of activation detectors was installed inside the TEXTOR vacuum vessel to perform these measurements. After irradiation, the detectors were analyzed using ultra low level gamma-ray spectrometry at the HADES underground laboratory. 3 MeV escaping fusion protons were detected in larger number −∼6 times more - compared to earlier measurements using this technique on JET. Another major progress was the reduction of the cooling time by a factor of 50, which made possible to detect radionuclides with half-life of less than 90 min.
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29.40.-n Radiation detectors
41.85.Si Particle beam collimators, monochromators
52.55.Fa Tokamaks, spherical tokamaks
52.55.Jd Magnetic mirrors, gas dynamic traps
52.70.-m Plasma diagnostic techniques and instrumentation
07.68.+m Photography, photographic instruments; xerography
07.85.-m X- and γ-ray instruments
07.85.Nc X-ray and γ-ray spectrometers
29.30.Kv X- and γ-ray spectroscopy
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