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BURNING PLASMA DIAGNOSTICS: An International Conference Date: 24–28 September 2007 Location: Varenna (Italy) ISBN: 978-0-7354-0507-3 Editor(s): Giuseppe Gorini, Francesco P. Orsitto, Elio Sindoni, Marco Tardocchi

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Experience On Plasma Diagnostics On JET

Peter E. Stott

AIP Conf. Proc. 988, pp. 3-8; doi:http://dx.doi.org/10.1063/1.2905105 (6 pages)

Online Publication Date: 17 March 2008

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This year marks the 30th anniversary of the decision on 17 October 1977 by the European Council of Ministers to proceed with the JET project. Very little thought had been given to the diagnostic requirements during the design phase—indeed many people assumed that JET would not do detailed physics studies and would need only a few basic diagnostics. Of course this view turned out to be incorrect—JET needed a comprehensive set of diagnostics and has conducted a very extensive physics programme. The large physical dimensions of JET, the radiation environment and the stringent interface standards radically changed our concept of diagnostics compared to the smaller fusion experiments that had gone before. In this paper I will review some of the experience on burning plasma diagnostics on JET.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.55.Jd Magnetic mirrors, gas dynamic traps

Some Lessons from the Burning Plasma Diagnostics in TFTR

Kenneth M. Young and David W. Johnson

AIP Conf. Proc. 988, pp. 9-16; doi:http://dx.doi.org/10.1063/1.2905126 (8 pages)

Online Publication Date: 17 March 2008

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A number of alpha‐particle diagnostics were initiated successfully during the TFTR DT phase. These diagnostics were prototypical and were not able to operate under all conditions. Had TFTR continued to operate, the deficiencies should have been corrected. Effects of radiation on fiberoptics and other components, lack of sufficient power in collective scattering and the effects of neutral beams on pellet ablation impacting pellet charge‐exchange were specific deficiencies in alpha—particle diagnostics. For understanding of the alpha source profile, the importance of very detailed calibrations of neutron diagnostics must be stressed. The interactions of fast ions with instabilities have been taken further in later devices but some aspects were already clear in the DT phase.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.55.Jd Magnetic mirrors, gas dynamic traps

Diagnostics Challenges for Burning Plasma Experiments

A. J. H. Donné, A. E. Costley, and ITPA Topical Group on Diagnostics

AIP Conf. Proc. 988, pp. 17-26; doi:http://dx.doi.org/10.1063/1.2905062 (10 pages)

Online Publication Date: 17 March 2008

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Many challenges are encountered in the design of diagnostics for a burning plasma experiment commencing with the definition of the measurement requirements in a coherent way. The specific hostile environment of the burning plasma experiment gives rise to many phenomena that are new to the diagnostics design (radiation‐induced effects, long pulses, high particle fluxes, strong relativistic effects, etc.). This presents an overview of the main diagnostics challenges and briefly outlines some of the solutions being developed to meet them.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.50.-b Plasma production and heating
52.55.Jd Magnetic mirrors, gas dynamic traps

Requirements for Plasma and First Wall Measurements on ITER

A. E. Costley, P. Andrew, R. L. Boivin, C. Ingesson, D. Johnson, G. Vayakis, and K. Young

AIP Conf. Proc. 988, pp. 27-34; doi:http://dx.doi.org/10.1063/1.2905081 (8 pages)

Online Publication Date: 17 March 2008

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In this paper we outline the process that is in use for developing the requirements for plasma and first wall measurements on ITER. These requirements are the starting point in the selection, design and integration of the individual measurement systems that together make up the ITER diagnostic system. We describe the issues that have arisen in the defining process and we give the current status. We take a brief forward look at some aspects of the measurement requirements for a next step (DEMO).
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52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.50.-b Plasma production and heating
52.55.Jd Magnetic mirrors, gas dynamic traps

Technology Issues of Burning Plasma Diagnostics

A. S. Kaye

AIP Conf. Proc. 988, pp. 35-42; doi:http://dx.doi.org/10.1063/1.2905099 (8 pages)

Online Publication Date: 17 March 2008

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The ITER Tokamak will require many diagnostics both for safe and reliable operation of the machine and for understanding of the physics underlying the performance. The design of these diagnostics raises many challenging technical issues not faced on smaller machines. These arise partly from the increase demands on established diagnostics arising from the increased size, higher magnetic field, large heating power, and in particular the dramatically longer pulse duration of ITER, which make issue such as power loading on first wall components more challenging. The demands on reliability and availability of the machine in order to achieve the objectives within the agreed time schedule also place severe additional demands on the design, quality assurance and maintainability of diagnostics. ITER will produce many orders of magnitude more neutrons than previous Tokamaks and will be a licensed nuclear facility. This has important implications for the traceability, quality assurance and availability of safety critical diagnostics, and for the control of the design and procurement of all diagnostics. The high neutron flux∕fluence also constrains the design of diagnostics, which must offer shielding consistent with the allowable dose rates on critical components of the Tokamak, and themselves be tolerant of the radiation level at the diagnostic. This paper presents an overview of the more critical issues for ITER diagnostics.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.50.-b Plasma production and heating
52.55.Jd Magnetic mirrors, gas dynamic traps
28.52.-s Fusion reactors

Reactor Implications For Burning Plasma Diagnostics

C. Gordon, D. Baker, and C. Walker

AIP Conf. Proc. 988, pp. 43-51; doi:http://dx.doi.org/10.1063/1.2905112 (9 pages)

Online Publication Date: 17 March 2008

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Reactors based on DT fusion will impose certain requirements and pose challenges for diagnostics. These relate, for example, to the need for such facilities to address the safety aspects of using tritium and high neutron fluxes leading to activation and radiation fields. There are also implications arising from the need for high machine availability and hence reliability of critical diagnostics. This paper will focus on the safety and licensing implications using design issues for typical diagnostic types to illustrate the above.
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52.55.-s Magnetic confinement and equilibrium
28.52.Nh Safety
52.70.-m Plasma diagnostic techniques and instrumentation
52.50.-b Plasma production and heating

Plant Models for DEMO

David Maisonnier

AIP Conf. Proc. 988, pp. 52-59; doi:http://dx.doi.org/10.1063/1.2905121 (8 pages)

Online Publication Date: 17 March 2008

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The European Power Plant Conceptual Study (PPCS) has been a study of conceptual designs for commercial fusion power plants. It focused on five power plant models, named PPCS A, B, AB, C and D, which are illustrative of a wider spectrum of possibilities. The PPCS study highlighted the need for specific design and R&D activities as well as the need to clarify the concept of DEMO, the device that will bridge the gap between ITER and the first fusion power plant. An assessment of the PPCS models with limited extrapolations has led to the clarification of the objectives of DEMO. Many parameters will have to be controlled in DEMO in order (1) to control the machine, (2) to satisfy the testing requirements, (3) to satisfy regulatory requirements (primarily safety), and (4) to protect the investment. On the other, DEMO will ulilise one or two plasma scenarios only.
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52.55.Jd Magnetic mirrors, gas dynamic traps
28.52.Nh Safety
52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.25.Tx Emission, absorption, and scattering of particles

Physics of ECE Temperature Measurements and Prospects for ITER

E. de la Luna and JET‐EFDA contributors

AIP Conf. Proc. 988, pp. 63-72; doi:http://dx.doi.org/10.1063/1.2905122 (10 pages)

Online Publication Date: 17 March 2008

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The physics of the electron cyclotron emission (ECE) temperature measurements is reviewed. The current understanding of the expected ECE spectra in ITER is summarized, for perpendicular as well as oblique propagation. The relevance of the use of oblique ECE for investigating the shape of the electron distribution function at low energies is discussed.
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52.25.Tx Emission, absorption, and scattering of particles
28.52.-s Fusion reactors
52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.55.Jd Magnetic mirrors, gas dynamic traps
29.20.dg Cyclotrons

Measurements of Electron Velocity Distribution Function (invited paper)

C. Sozzi, E. De La Luna, D. Farina, J. Fessey, L. Figini, S. Garavaglia, G. Grossetti, S. Nowak, P. Platania, A. Simonetto, M. Zerbini, and JET EFDA contributors

AIP Conf. Proc. 988, pp. 73-80; doi:http://dx.doi.org/10.1063/1.2905123 (8 pages)

Online Publication Date: 17 March 2008

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Deviations of the electron function velocity distribution from Maxwellian behavior in the high energy range have been extensively studied during the past two decades. A brief review of the experimental techniques and findings on the subject is given in this paper. There are indications that the electron distribution function in thermonuclear plasmas could be significantly different from the Maxwellian one even near the thermal velocity range when particular circumstances occur. These reasons motivate a renewed effort in the measurements that could detect low energies distortions, among which is the new Oblique Electron Cyclotron Emission diagnostics that has entered operations during 2006 experimental campaign at JET and aims to resolve relatively small differences in the ECE spectra taken at three toroidal angles. Such measurements allow insight into the characteristics of the electron distribution function. First results of such experimental system are discussed in this paper, along with emission simulations.
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52.25.Tx Emission, absorption, and scattering of particles
52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Jd Magnetic mirrors, gas dynamic traps
29.20.dg Cyclotrons

Thomson Scattering and Burning Plasmas

M. J. Walsh

AIP Conf. Proc. 988, pp. 81-91; doi:http://dx.doi.org/10.1063/1.2905124 (11 pages)

Online Publication Date: 17 March 2008

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In low temperature plasmas, tokamaks and other experimental fusion devices, the electron temperature and densities in the plasma can be measured with high accuracy by detecting the effect of Thomson scattering of light from a high‐intensity laser fired through the device. It has been established as a robust technique to measure these parameters and in particular it can be used to provide detailed profiles right through the plasma.
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52.55.Fa Tokamaks, spherical tokamaks
52.55.Jd Magnetic mirrors, gas dynamic traps
52.70.-m Plasma diagnostic techniques and instrumentation
52.50.-b Plasma production and heating
52.25.Os Emission, absorption, and scattering of electromagnetic radiation
42.55.-f Lasers

Advanced Interferometry Techniques for Burning Plasmas

D. L. Brower, W. X. Ding, V. V. Mirnov, M. A. Van Zeeland, and T. N. Carlstrom

AIP Conf. Proc. 988, pp. 92-102; doi:http://dx.doi.org/10.1063/1.2905125 (11 pages)

Online Publication Date: 17 March 2008

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For future burning plasma experiments, all diagnostics must be re‐evaluated in terms of their measurement capabilities and robustness to the new environment. This is certainly true for interferometry measurements where conventional approaches may not be ideal and interpretation may require modification due to high plasma temperatures. Optimizing these systems to provide maximum information will be crucial to understanding burning plasma dynamics. This paper will explore a variety of phase measurement techniques for the main body and divertor regions that can be utilized on burning plasma experiments like ITER and beyond.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.50.-b Plasma production and heating
52.55.Fa Tokamaks, spherical tokamaks

Measurements of Alfvén Eigenmodes in Fusion Plasmas

M. A. Van Zeeland and G. J. Kramer

AIP Conf. Proc. 988, pp. 103-109; doi:http://dx.doi.org/10.1063/1.2905049 (7 pages)

Online Publication Date: 17 March 2008

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Ensuring appropriate measurements of Alfvén eigenmodes in burning plasma experiments will allow the validation of predictions of alpha driven instabilities in plasmas dominated by self heating from fusion produced alpha particles and provide the control capability for optimizing performance, reducing the alpha particle losses due to these modes, and minimizing potential first wall damage. This paper gives a brief overview of several of the relevant Alfvén eigenmodes in burning plasma experiments as well as the theoretical tools currently being used to model them. A procedure is then outlined in which predicted Alfvén eigenmodes from the ideal MHD code NOVA can be used to simulate the performance of diagnostics on future devices with respect to measurements of these modes. A preliminary application of the technique to ITER's tangential CO2 interferometer is discussed and it is found that the system should be more than adequate to resolve Alfvénic fluctuations with amplitudes in the range of those commonly encountered on current devices.
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52.55.Fa Tokamaks, spherical tokamaks
52.70.-m Plasma diagnostic techniques and instrumentation
52.50.-b Plasma production and heating
52.35.Bj Magnetohydrodynamic waves (e.g., Alfven waves)

Development of laser‐aided plasma diagnostics and related technology

K. Kawahata, T. Akiyama, R. Pavlichenko, K. Tanaka, K. Nakayama, and S. Okajima

AIP Conf. Proc. 988, pp. 110-117; doi:http://dx.doi.org/10.1063/1.2905050 (8 pages)

Online Publication Date: 17 March 2008

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Laser‐aided plasma diagnostics, aiming for establishment of reliable density measurement in next step magnetically confined fusion devices, are under development at the National Institute for Fusion Science. A new type of two color laser (57.2∕47.6‐μm CH3OD) interferometer has been developed and its original function, vibration subtraction, was confirmed in a test stand. The line integrated density measurements by the polarimeter were demonstrated at Compact Helical System by the Cotton‐Mouton polarimeter and at the LHD by the Faraday rotation polarimater.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
07.60.Ly Interferometers

Fast Ion Collective Thomson Scattering Diagnostic for ITER ‐ Progress of Design

S. B. Korsholm, H. Bindslev, V. Furtula, F. Leipold, F. Meo, P. K. Michelsen, S. Michelsen, M. Salewski, and E. L. Tsakadze

AIP Conf. Proc. 988, pp. 118-122; doi:http://dx.doi.org/10.1063/1.2905051 (5 pages) | Cited 1 time

Online Publication Date: 17 March 2008

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In the era of high power and burning plasma fusion experiments with significant populations of fast particles, the diagnosis of fast ion dynamics becomes an important topic. In ITER, populations of fast ions due to ICRH and NBI, as well as fusion born alphas will carry a significant fraction of the free energy of the plasma. This may affect instabilities and transport in the plasma. A key candidate for diagnosing confined fast ions in ITER is the technique of collective Thomson scattering (CTS). A fast ion CTS system with a probing frequency of 60 GHz has been proposed for ITER. Based on diagnostic experience from particularly TEXTOR and ASDEX Upgrade, work is now progressing towards a final design of a fast ion CTS diagnostic for ITER. The biggest challenge of the diagnostic design is the HFS receiver located in the restricted space behind the blanket modules. Calculations and a series of mock‐up measurements have brought the design towards a four mirror quasi‐optical solution. The development as well as the present design will be presented.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.25.Os Emission, absorption, and scattering of electromagnetic radiation
52.50.-b Plasma production and heating
28.52.-s Fusion reactors

Comparison of Inboard‐Outboard Pedestal Temperature Measurements in JET Using ECE Diagnostics

L. Barrera, E. de la Luna, L. Figini, and JET EFDA Contributors

AIP Conf. Proc. 988, pp. 123-127; doi:http://dx.doi.org/10.1063/1.2905052 (5 pages)

Online Publication Date: 17 March 2008

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Despite considerable effort, both theoretically and experimentally, a complete physical model to describe the particle and energy losses during ELMs is far from complete. On the experimental front, improved description of the spatial structure (poloidal asymmetry, radial distribution) and the dynamics of the ELM crash is a key requirement to answer some of the basic outstanding questions concerning the physics of ELMs. A significant number of diagnostics is now capable of fast measurements of the pedestal profile during an ELM, however, there is a lack of data from the inboard midplane, so assumptions of poloidal symmetry on the flux surfaces have often to be made. The aim of this work is to explore the capabilities of the electron cyclotron emission (ECE) diagnostics to provide simultaneous measurements of the edge temperature for both inboard and outboard plasma midplane. Access to the inboard region of the plasma is achieved in JET by using 1 harmonic∕O‐mode polarization, as it is not affected by harmonic overlap with the 2nd harmonic. This paper focuses on the validation of the inboard ECE data and the identification of the limitations of the measurements and the data analysis.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.25.Tx Emission, absorption, and scattering of particles
52.25.Os Emission, absorption, and scattering of electromagnetic radiation

SPECE: a code for Electron Cyclotron Emission in tokamaks

D. Farina, L. Figini, P. Platania, and C. Sozzi

AIP Conf. Proc. 988, pp. 128-131; doi:http://dx.doi.org/10.1063/1.2905053 (4 pages) | Cited 1 time

Online Publication Date: 17 March 2008

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The code SPECE has been developed for the analysis of electron cyclotron emission (ECE) in a general tokamak equilibrium. The code solves the radiation transport equation along the ray trajectories in a tokamak plasma, in which magnetic equilibrium and plasma profiles are given either analytically or numerically, for a Maxwellian plasma or a non thermal plasma characterized by a distribution function that is the sum of drifting Maxwellian distributions. Ray trajectories are computed making use of the cold dispersion relation, while the absorption and emission coefficients are obtained solving the relevant fully relativistic dispersion relation valid at high electron temperature. The actual antenna pattern is simulated by means of a multi‐rays calculation, and the spatial resolution of the ECE measurements is computed by means of an algorithm that takes properly into account the emission along each ray of the beam. Wall effects are introduced in the code by means of a heuristic model. Results of ECE simulations in a standard ITER scenario are presented.
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52.55.Fa Tokamaks, spherical tokamaks
52.25.Tx Emission, absorption, and scattering of particles
52.70.-m Plasma diagnostic techniques and instrumentation
52.25.Os Emission, absorption, and scattering of electromagnetic radiation

Compact high‐speed high‐sensitivity second‐harmonic interferometer for electron density measurement

F. Brandi, P. Marsili, and F. Giammanco

AIP Conf. Proc. 988, pp. 132-135; doi:http://dx.doi.org/10.1063/1.2905054 (4 pages) | Cited 1 time

Online Publication Date: 17 March 2008

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A second‐harmonic interferometer based on a CW Nd:YAG laser is presented. The device is extremely compact and versatile and is developed for line‐integrated electron density measurements in large plasma machines. A sensitivity in measuring line‐integrated electron density of 4×1013 cm−2 with time resolution of 8 μs, and 1013 cm−2 with time resolution of 50 μs, is demonstrated.
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07.60.Ly Interferometers
06.30.Dr Mass and density
52.70.-m Plasma diagnostic techniques and instrumentation
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation

The Interferometer As An Optical Mixer: A Novel Approach To Far Infrared Spectroscopy

M. Zerbini and E. Franconi

AIP Conf. Proc. 988, pp. 136-139; doi:http://dx.doi.org/10.1063/1.2905055 (4 pages)

Online Publication Date: 17 March 2008

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In Tokamaks, the Electron Cyclotron Emission (ECE) radiation frequency spans from 80 GHz up to 1 THz for high magnetic field (Bt>5 T) and higher harmonics (n>2). This frequency ranges between Microwaves and Far Infrared (FIR), moulding an intrinsically hybrid nature for ECE diagnostics(1). Signal detection is carried out in two surprisingly different ways: electronics and optics. The two detection methods, beyond the chief external differences, are conceptually the same. The dualism often reflects the mindset of the laboratory performing the measurement. In this paper we discuss a different approach to an integrated instrument. A traditional quasi‐optical interferometer is the first down‐conversion stage with intrinsic broad band capability. Its output signal can then be analysed with a radio‐style detection, in the amenable kHz frequency range.
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52.25.Tx Emission, absorption, and scattering of particles
52.55.Fa Tokamaks, spherical tokamaks
07.60.Ly Interferometers
52.70.Gw Radio-frequency and microwave measurements

Models comparison for JET polarimeter data

C. Mazzotta, F. P. Orsitto, A. Boboc, E. Giovannozzi, M. Brombin, A. Murari, O. Tudisco, L. Zabeo, and EFDA‐JET Contributors

AIP Conf. Proc. 988, pp. 140-143; doi:http://dx.doi.org/10.1063/1.2905056 (4 pages)

Online Publication Date: 17 March 2008

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A complete comparison between the theory and the measurements in polarimetry was done by using the Far Infrared Polarimeter at JET. More than 300 shots were analyzed, including a wide spectrum of JET scenarios in all critical conditions for polarimetry: high density, high and very low fields, high temperatures.
This work is aimed at the demonstration of the robustness of the theoretical models for the JET polarimeter measurements in the perspective of using these models for ITER like plasma scenarios . In this context, an assessment was performed on how the line‐integrated plasma density along the central vertical chord of FIR polarimeter could be evaluated using the Cotton‐Mouton effect and its possible concrete use to correct fringe jumps of the interferometer.
The models considered are: i) the rigorous numerical solution of the Stokes propagation equations, using dielectric tensor evaluated from JET equilibrium and Thomson scattering [1,2]; ii) two types of approximated solutions [2,3] and iii) the Guenther empirical model [4] that considers the mutual effect between Cotton‐Mouton and Faraday rotation angle. The model calculations have been compared with polarimeter measurements for the Cotton‐Mouton phase shift.
The agreement with theory is satisfactory within the limits of experimental errors [3].
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78.20.Ls Magneto-optical effects
07.60.Fs Polarimeters and ellipsometers
52.25.-b Plasma properties
52.70.-m Plasma diagnostic techniques and instrumentation

Study of Fast, Near‐Infrared Photodetectors for the ITER Core LIDAR Thomson Scattering

L. Giudicotti, R. Pasqualotto, A. Alfier, M. Beurskens, M. Kempenaars, and M. J. Walsh

AIP Conf. Proc. 988, pp. 144-147; doi:http://dx.doi.org/10.1063/1.2905057 (4 pages)

Online Publication Date: 17 March 2008

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A key component for the ITER core LIDAR Thomson Scattering (TS) diagnostic would be a detector with good sensitivity in the 850‐1060 nm near infrared (NIR) spectral region. Covering this spectral region becomes necessary if a Nd:YAG laser system operating at λ  =  1.06 μm is used as the laser source, which is a very attractive choice in terms of available energy, repetition rate, reliability and cost. In this paper we review the state of the art of two types of detectors available for the above spectral range: the transferred electron (TE) InGaAs∕InP hybrid photodiode and the InxGa1−xAs microchannel plate (MCP) image intensifier and we describe the advancements necessary for a possible application in the ITER LIDAR TS. In addition we describe the preliminary characterization of new GaAsP fast MCP photomultipliers (PMTs) suitable for the detection of the visible part of the LIDAR TS spectrum in JET and ITER.
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52.70.-m Plasma diagnostic techniques and instrumentation
52.25.Os Emission, absorption, and scattering of electromagnetic radiation
85.60.Ha Photomultipliers; phototubes and photocathodes

Dust Measurement With Thomson Scattering In FTU

E. Giovannozzi, C. Castaldo, G. Maddaluno, S. Ratynskaia, and A. Rydzy

AIP Conf. Proc. 988, pp. 148-151; doi:http://dx.doi.org/10.1063/1.2905058 (4 pages) | Cited 2 times

Online Publication Date: 17 March 2008

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The size distribution of dust particles present in FTU after disruptions has been evaluated in the range 0.05 μm–0.1 μm using the Thomson scattering system. Rayleigh approximation has been used to estimate the dust size. The distribution, although the radii considered do not differ more than an order of magnitude, behave like a power law. The laser energy density far exceed that necessary to vaporize, at least partially, the particles. This can affect the previous estimate of the particle sizes, and suggests that the effective radii might be larger than the estimated values. A preliminary analysis on the broad band signal is presented.
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52.27.Lw Dusty or complex plasmas; plasma crystals
52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.25.Os Emission, absorption, and scattering of electromagnetic radiation

Passive Spectroscopy Bolometers, Grating‐ And X‐ray Imaging Crystal Spectrometers

M. Bitter, K. W. Hill, S. Scott, S. Paul, A. Ince‐Cushman, M. Reinke, J. E. Rice, P. Beiersdorfer, M. F. Gu, S. G. Lee, Ch. Broennimann, and E. F. Eikenberry

AIP Conf. Proc. 988, pp. 155-164; doi:http://dx.doi.org/10.1063/1.2905059 (10 pages)

Online Publication Date: 17 March 2008

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This tutorial gives a brief introduction into passive spectroscopy and describes the working principles of bolometers, a high‐resolution grating spectrometer, and a novel X‐ray imaging crystal spectrometer, which is also of particular interest for profile measurements of the ion temperature and plasma rotation velocity on ITER and future burning plasma experiments.
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52.55.Jd Magnetic mirrors, gas dynamic traps
52.55.Fa Tokamaks, spherical tokamaks
52.70.La X-ray and γ-ray measurements
52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.50.-b Plasma production and heating

Active Beam Spectroscopy

M. G. von Hellermann, E. Delabie, R. J. E. Jaspers, W. Biel, O. Marchuk, H. P. Summers, A. Whiteford, C. Giroud, N. C. Hawkes, and K. D. Zastrow

AIP Conf. Proc. 988, pp. 165-176; doi:http://dx.doi.org/10.1063/1.2905060 (12 pages) | Cited 3 times

Online Publication Date: 17 March 2008

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Charge eXchange Recombination Spectroscopy (CXRS) plays a pivotal role in the diagnostics of hot fusion plasmas and is implemented currently in most of the operating devices. In the present report the main features of CXRS are summarized and supporting software packages encompassing “Spectral Analysis Code CXSFIT”, “Charge Exchange Analysis Package CHEAP”, and finally “Forward Prediction of Spectral Features” are described.
Beam Emission Spectroscopy (BES) is proposed as indispensable cross‐calibration tool for absolute local impurity density measurements and also for the continuous monitoring of the neutral beam power deposition profile. Finally, a full exploitation of the ‘Motional Stark Effect’ pattern is proposed to deduce local pitch angles, total magnetic fields and possibly radial electric fields.
For the proposed active beam spectroscopy diagnostic on ITER comprehensive performance studies have been carried out. Estimates of expected spectral signal‐to‐noise ratios are based on atomic modelling of neutral beam stopping and emissivities for CXRS, BES and background continuum radiation as well as extrapolations from present CXRS diagnostic systems on JET, Tore Supra, TEXTOR and ASDEX‐UG.
Supplementary to thermal features a further promising application of CXRS has been proposed recently for ITER, that is a study of slowing‐down alpha particles in the energy range up to 2 MeV making use of the 100 keV∕amu DNB (Diagnostic Neutral Beam) and the 500 keV∕amu HNB (Heating Neutral Beam). Synthetic Fast Ion Slowing‐Down spectra are evaluated in terms of source rates and slowing‐down parameters
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52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.55.Fa Tokamaks, spherical tokamaks
52.25.Vy Impurities in plasmas
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Neutral Particle Analysis on ITER and requirements for DEMO

V. I. Afanasyev, M. I. Mironov, S. V. Konovalov, A. V. Khudoleev, M. P. Petrov, S. S. Kozlovsky, V. G. Nesenevich, B. V. Lyublin, S. Ya. Petrov, A. I. Kislyakov, F. V. Chernyshev, and A. D. Melnik

AIP Conf. Proc. 988, pp. 177-184; doi:http://dx.doi.org/10.1063/1.2905061 (8 pages)

Online Publication Date: 17 March 2008

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The use of the neutral particle analysis (NPA) to study the ion component of plasma on ITER has been reviewed. Both thermal (10–200 keV) and supra‐thermal (0.2–4 MeV) energy ranges of neutral fluxes are studied in respect to feasibility of the fusion fuel isotopic composition measurements. Influence of heating neutral beams and diagnostic neutral beam on the measurements is also shown. Possible application of the NPA to measure the energy distribution function of fusion alpha particles is discussed. Low‐ and high‐energy NPA monitors have been proposed for DEMO machine to control the DT fuel isotope ratio.
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52.25.Ya Neutrals in plasmas
52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
52.55.Pi Fusion products effects (e.g., alpha-particles, etc.), fast particle effects

Fast visible camera installation and operation in JET

J. A. Alonso, P. Andrew, A. Neto, J. L. de Pablos, E. de la Cal, H. Fernandes, J. Gafert, P. Heesterman, C. Hidalgo, G. Kocsis, A. Manzanares, A. Murari, G. Petravich, L. Rios, C. Silva, et al.

AIP Conf. Proc. 988, pp. 185-188; doi:http://dx.doi.org/10.1063/1.2905063 (4 pages)

Online Publication Date: 17 March 2008

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This article is a summary of the measurements of the recently installed wide‐view fast visible camera in the Joint European Tokamak JET. Here we limit ourselves to a description of the different phenomena and leave for forthcoming articles a more extensive analysis of every phenomenon.
Show PACS
52.55.Fa Tokamaks, spherical tokamaks
07.68.+m Photography, photographic instruments; xerography
42.79.Pw Imaging detectors and sensors
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