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Gamma diagnostics is considered to be primary for the confined a- particles and runaway electrons measurements on ITER. The gamma spectrometer will be embedded into a neutron dump of the ITER Neutral Particle Analyzer diagnostic complex. It will supplement NPA measurements on the fuel isotope ratio and confined alphas/fast ions. In this paper an update on ITER gamma spectrometer developments is given. A new geometry of the system is described and detailed analysis of expected signals for the spectrometer is presented. [ABSTRACT FROM AUTHOR]

JET equipped with ITER-like wall (a beryllium wall and a tungsten divertor) can provide auxiliary heating with power up to 35MW, producing a significant population of a-particles in DT operation. The direct measurements of alphas are very difficult and a-particle studies require a significant development of dedicated diagnostics. JET now has an excellent set of confined and lost fast particle diagnostics for measuring the a-particle source and its evolution in space and time, a-particle energy distribution, and a-particle losses. This paper describes how the above mentioned JET diagnostic systems could be used for a-particle measurements, and what options exist for keeping the essential a-particle diagnostics functioning well in the presence of intense DT neutron flux. Also, a-particle diagnostics for ITER are discussed. [ABSTRACT FROM AUTHOR]

The diagnostic systems of DEMO that are mounted on or near the torus, whether intended for the monitoring and control functions of the engineering aspects or the physics behaviour of the machine, will have to be designed to suit the hostile nuclear environment. This will be necessary not just for their survival and correct functioning but also to satisfy the pertinent regulatory bodies, especially where any of them relate to machine protection or the prevention or mitigation of accidents foreseen in the safety case. This paper aims to indicate the more important of the reactor design considerations that are likely to apply to diagnostics for DEMO, drawn from experience on JET, the provisions in hand for ITER and modelling results for the wall erosion and neutron damage effects in DEMO. [ABSTRACT FROM AUTHOR]

SyLMAND, the Synchrotron Laboratory for Micro and Nano Devices at the Canadian Light Source, consists of a dedicated X-ray lithography beamline on a bend magnet port, and process support laboratories in a clean room environment. The beamline includes a double mirror system with flat, chromium-coated silicon mirrors operated at varying grazing angles of incidence (4 mrad to 45 mrad) for spectral adjustment by high energy cut-off. Each mirror can be independently moved by two stepper motors to precisely control the pitch and vertical position. We present in this paper the machine protection system implemented in the double mirror system to allow for safe operation of the two mirrors and to avoid consequences of potential stepper motor malfunction. [ABSTRACT FROM AUTHOR]

The U.S. Nuclear Regulatory Commission (NRC) has undertaken a program to lay the technical foundations for defining proactive actions to manage degradation of materials in light water reactors. The current focus is existing plants; however, if applied to new construction, there is potential to better monitor and manage plants throughout their life cycle. This paper discusses the NRC’s Proactive Management of Materials Degradation program and its application to nuclear power plant structures, systems, and components. [ABSTRACT FROM AUTHOR]

In the nineteen-sixties, a significant limitation of NDI and NDE became apparent with the advent of fracture mechanics. Fracture mechanics requires quantitative information on defects, which has to be obtained from quantitative non-destructive testing. A DARPA Program directed by Don Thompson provided the point of departure for the journey to put the Q with NDE. The DARPA Program, and subsequent DOD, FAA and industrial programs produced seminal results for diagnostics and prognostics. In diagnostics, measurement models, probability of detection considerations and techniques of defect characterization were developed, which were complemented by damage evolution laws, probabilistic failure analysis and damage progression estimates, for methods of prognostication. The new results in QNDE naturally led to the concept of structural health monitoring (SHM), whereby sensors are permanently installed on structures. An SHM system can provide on-demand (or continuous) information on the state of a structure, so that an assessment of the structural integrity can be made at any time, and timely remedial actions can be taken. In this paper, we review the development of QNDE towards SHM. Sensor development, data processing, materials engineering and solid mechanics play dominant roles in both the diagnostic and the prognostic components of SHM. A probabilistic approach is essential, as will be shown by examples of pre-crack fatigue damage, crack growth and optimization of an inspection schedule. [ABSTRACT FROM AUTHOR]

A study of magnetically confined fast ions in tokamaks plays an important role in burning plasma research. To reach ignition and steady burning of a reactor plasma an adequate confinement of energetic ions produced by NBI heating, accelerated with ICRF and born in fusion reactions is essential to provide efficient heating of the bulk plasma. Thus, investigation of the fast ion behaviour is an immediate task for present-day large machines, such as JET, in order to understand the main mechanisms of slowing down, redistribution and losses, and to develop optimal plasma scenarios. Today's JET has an enhanced suite of fast ion diagnostics both of confined and lost ions that enable to significantly contribute to this important area of research. Fast ion populations of p, d, t, 3He and 4He, made with ICRF, NBI, and fusion reactions have been investigated in experiments on JET with sophisticated diagnostics in conventional and shear-reversed plasmas, exploring a wide range of effects. This paper will introduce to the JET fast-ion diagnostic techniques and will give an overview of recent observations. A synergy of the unique diagnostic set was utilised in JET, and studies of the response of fast ions to MHD modes (e.g. tornado modes, sawtooth crashes), fast 3He-ions behaviour in shear-reversed plasmas are impressive examples of that. Some results on fast ion losses in JET experiments with various levels of the toroidal field ripple will be demonstrated. [ABSTRACT FROM AUTHOR]

The roles of fusion products in diagnosing plasmas are quite diversified and rich in scientific content. From the early days to the new frontier of burning plasmas, the study of fusion products has allowed a deeper understanding of the physics found in these plasmas, spanning all configurations, in both magnetic and inertial confinement. In many early experiments, the measurement of plasma performance was based almost entirely on neutron yield measurements. Since then, the capability to measure fusion products has grown tremendously, and many new measuring techniques have been successfully tested and used in experiments. The first role is based on single-particle diagnosis, which can yield important information on performance, confinement, source and current profiles, plasma fluctuations, effects of ripples, MHD mode structure, etc. The second role, which has expanded tremendously in the last few years, includes the diagnosis of collective effects, which can yield additional information on instabilities, heating, and many others. This scientific capability is enhanced by the large number of fusion products (neutrons, charged particles, gammas) generated by the primary or secondary fusion processes such as the commonly studied, D+D, D+T and D+3He reactions. This paper will review the applications of fusion product measurements used in the scientific study of plasma confinement and stability, and will describe the prospects and opportunities offered in burning plasma experiments such as ITER. [ABSTRACT FROM AUTHOR]

A central task for fusion plasma diagnostics is to measure the 2.5 and 14 MeV neutron emission rate in order to determine the fusion power. A new method for determining the neutron yield has been developed at JET. It makes use of the magnetic proton recoil neutron spectrometer and a neutron camera and provides the neutron yield with small systematic errors. At ITER a similar system could operate if a high-resolution, high-performance neutron spectrometer similar to the MPR was installed. In this paper, we present how such system could be implemented and how well it would perform under different assumption of plasma scenarios and diagnostic capabilities. It is found that the systematic uncertainty for using such a system as an absolute calibration reference is as low as 3 % and hence it would be an excellent candidate for the calibration of neutron monitors such as fission chambers. It is also shown that the system could provide a 1 ms time resolved estimation of the neutron rate with a total uncertainty of 5 %. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In the recent years Plasma Control has always increased his importance in any advanced experiment. It is now clear that ITER will not be able to operate without a quite advanced and sophisticated control apparatus. Necessarily this system will have to integrate several different aspects of the Plasma behavior. One of the most important parts of a closed loop control system is the quality of the measurement of the plasma parameters that should be controlled. Eventually, this aspect involves sophisticated and complex diagnostic apparatus. This paper presents an overview of the present status, and further studies and developments needed, in the next future, for the design and realization of an integrated plasma control system aimed at both stabilizing the plasma non-axisymmetric instabilities and controlling the most important internal plasma parameters. In particular the Edge Localized Modes (ELMs), the Neo-Classical Tearing Modes (NTM), the Resistive Wall Mode (RWM) and the Plasma Profiles control system necessities will be shortly illustrated. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A compact YAG (Chromium Doped Yttrium Aluminum Garnet — Cr4+:YAG) imaging system has been designed as a diagnostic tool for monochromatic x-rays emanating from the first “Hard” x-ray dual-canted undulator at the Advanced Photon Source at Argonne National Laboratory. This imaging system consists of a flat YAG crystal, right angle prism/mirror, video camera and monitor. A flat YAG crystal with a diameter of 10 mm has been installed in vacuum and positioned downstream of the monochromator of the insertion device beamline. Another 20 mm diameter YAG crystal has been installed in vacuum after the horizontal deflecting mirrors of the second insertion device beamline. CCD cameras are mounted in air close to the window of the vacuum ports to image the fluorescence of the YAG crystals. An additional 25 mm diameter YAG crystal has been used for K-B (Kirkpatrick-Baez) mirror focusing and beamline alignment. These YAG imaging systems have greatly facilitated beamline commissioning as well as sample alignment to the x-ray beam in the macromolecular crystallography endstation. An overview of the optics design, mechanical design and the performance of these devices will be presented in the paper. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

LISA PathFinder (LPF) will be flown with the objective to test in space key technologies for LISA. However its sensitivity goals are, for good reason, one order of magnitude less than those which LISA will have to meet, both in drag-free and optical metrology requirements, and in the observation frequency band. While the expected success of LPF will of course be of itself a major step forward to LISA, one might not forget that a further improvement by an order of magnitude in performance will still be needed. Clues for the last leap are to be derived from proper disentanglement of the various sources of noise which contribute to the total noise, as measured in flight during the PathFinder mission. This paper describes the principles, workings and requirements of one of the key tools to serve the above objective: the diagnostics subsystem. This consists in sets of temperature, magnetic field, and particle counter sensors, together with generators of controlled thermal and magnetic perturbations. At least during the commissioning phase, the latter will be used to identify feed-through coefficients between diagnostics sensor readings and associated actual noise contributions. A brief progress report of the current state of development of the diagnostics subsystem will be given as well. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Emittance is one of the major characteristics of charged particle beams. In this paper, we will present techniques used for measuring emittance for the sources, linear and circular accelerators. Invasive and non-invasive methods are described and their advantages and limitations are discussed. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The paper presents the optimization of a methodology for automatic clustering based on Artificial Neural Networks to detect the presence of defects in rolling bearings. The research activity was developed in co-operation with an Italian company which is expert in the production of water pumps for automotive use (Industrie Saleri Italo). The final goal of the work is to develop a system for the automatic control of the pumps, at the end of the production line. In this viewpoint, we are gradually considering the main elements of the water pump, which can cause malfunctioning. The first elements we have considered are the rolling bearing, a very critic component for the system. The experimental activity is based on the vibration measuring of rolling bearings opportunely damaged; vibration signals are in the second phase elaborated; the third and last phase is an automatic clustering. Different signal elaboration techniques are compared to optimize the methodology. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide maximum cooling of the antiprotons in the Recycler. A measurement system was developed using movable apertures and steering bumps to measure the beam size in a 20m long, nearly continuous, solenoid. This paper will focus on results of these measurements of the beam size and the difficulties in making those measurements. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]