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Nuclear Science, IEEE Transactions on

Issue 1 • Date Feb 1990

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Displaying Results 1 - 4 of 4
  • Vacuum protection system using an interlocked fast-closing valve for a high-power wiggler beam line

    Page(s): 2 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB)  

    The finite-element method was used to calculate a rise in temperature at a fast-closing valve (FCV) blade during exposure to intense synchrotron radiation from a 53-pole wiggler at the 2.5-GeV Photon Factory storage ring. The results indicate a possible meltdown of the titanium-alloy blade within 0.1 s at a maximum beam current of 500 mA, making the vacuum protection function of the FCV ineffective for an instantaneous vacuum failure downstream of the wiggler beam line. In order to prevent the blade from melting, the FCV control system has been interlocked with RF klystrons so as to initiate blade closure after dumping the electron beam by turning off the RF power. Performance tests have shown that the system could dump the electron beam within 95 μs and then close the blade within 12.4 ms after being triggered View full abstract»

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  • Monolithic integration of a nuclear radiation sensor and transistors on high-purity silicon

    Page(s): 15 - 20
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (592 KB)  

    The physical operation of nuclear radiation sensors is briefly reviewed. A description is given of a typical experimental measurement-system setup, which can be divided into two parts: the application-specific part (including the detector and its associated electronics) and the computer-interfaced part (consisting of a multichannel analyzer). A number of recent improvements in the system design are discussed, and an extended description and a physical example are given of one of the most promising new ideas-the monolithic integration of both the radiation sensor and its associated electronics on one high-ohmic silicon substrate. The results proved to be a stimulus for making nuclear radiation sensors smart enough for direct digital input into computer systems View full abstract»

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  • Optimization of resistively hardened latches

    Page(s): 7 - 14
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB)  

    The design of digital circuits tolerant to single-event upsets is considered. The results of a study in which an analytical model was used to predict the behavior of a standard resistively hardened latch are presented. It is shown that a worst-case analysis for all possible single-event upset situations (on the latch or in the logic) can be derived from studying the effects of a transient distributed write cycle. The existence of an intrinsic minimum write period to tolerate a transient of a given duration is also demonstrated. This minimum write period cannot be attained without proper resistor selection resulting from a complete optimization study. Analytic results are in sufficiently good agreement with SPICE results to guide simulation choices efficiently, and the model made it possible to develop a set of linear equations that allow the quick optimization of the studied latch for any transient durations and any IC CMOS processes View full abstract»

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  • Instrument failure detection and estimation methodology for the nuclear power plant

    Page(s): 21 - 30
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (692 KB)  

    To detect instrument failures in a nuclear power plant, a failure detection and isolation (FDI) method based on the Kalman filter is developed. Each filter is designed to be insensitive to the failed measurements by decreasing the Kalman gain artificially. Since it is mainly dependent upon the dynamic model and averaged outputs, it can exactly indicate the direction of failures. Even though this concept minimizes the number of filters, it performs the role of analytic redundancy for estimation. As soon as the residual exceeds the predetermined bound, the Kalman filter indicates the possibility of failures. However, since the measurement may show false indication owing to abrupt noises, it must be confirmed several times by the multiple consecutive miscomparison counter, which is strongly dependent on measurement history. Then, if it is not in accordance with other measurements, detailed information on the status of the measurements is provided to help the operator's decision. Various simulations were performed to verify and validate the FDI logic in detecting steam generator and pressurizer instrument failures. It is shown that the FDI technique can detect not only a single failure but also simultaneous common-mode and sequential multiple failures of several direct redundancies. It can correctly estimate the physical states in real time, and the remaining time may be used for control with signal validation View full abstract»

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Aims & Scope

IEEE Transactions on Nuclear Science focuses on all aspects of the theory and applications of nuclear science and engineering, including instrumentation for the detection and measurement of ionizing radiation; particle accelerators and their controls; nuclear medicine and its application; effects of radiation on materials, components, and systems; reactor instrumentation and controls; and measurement of radiation in space.

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