Use of higher order signal moments and high speed digital sampling technique for neutron flux measurement

Conference · Sun Aug 01 00:00:00 EDT 1993 · IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States)

OSTI ID:5889026

Baers, L B ^[1]; Gutierrez, T R; Mendoza, R A; Santana, G J ^[2]

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1. Technical Research Centre of Finland, Espoo (Finland) Inst. Nacional de Investigaciones Nucleares, Lomas Barrilaco (Mexico)
2. National Nuclear Research Inst., Mexico City (Mexico)

The second (conventional variance or Campbell signal) , , , the third , and the modified fourth order [minus] 3*[sup 2] etc. central signal moments associated with the amplified (K) and filtered currents [i[sub 1], i[sub 2], x = K * (i[sub 2]-),] from two electrodes of an ex-core neutron sensitive fission detector have been measured versus the reactor power of the 1 MW TRIGA reactor in Mexico City. Two channels of a high speed (400 kHz) multiplexing data sampler and A/D converter with 12 bit resolution and one megawords buffer memory were used. The data were further retrieved into a PC and estimates for auto- and cross-correlation moments up to the fifth order, coherence (/[radical]), skewness (/([radical]/)[sup 3]), excess (/[sup 2] - 3) etc. quantities were calculated off-line. A five mode operation of the detector was achieved including the conventional counting rates and currents in agreement with the theory and the authors previous results with analogue techniques. The signals were proportional to the neutron flux and reactor power in some flux ranges. The suppression of background noise is improved and the lower limit of the measurement range is extended as the order of moment is increased, in agreement with the theory. On the other hand the statistical uncertainty is increased. At increasing flux levels it was statistically more difficult to obtain flux estimates based on the higher order ([>=]3) moments.

• OSTI ID: 5889026
• Report Number(s): CONF-921005-; CODEN: IETNAE
• Journal Information: IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States), Vol. 40:4 part 1; Conference: Institute of Electrical and Electronic Engineers (IEEE) nuclear science symposium and medical imaging conference, Orlando, FL (United States), 25-31 Oct 1992; ISSN 0018-9499
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
FISSION CHAMBERS
DATA PROCESSING
REACTOR INSTRUMENTATION
TRIGA-3-SALAZAR REACTOR
ANALOG-TO-DIGITAL CONVERTERS
MULTIPLEXERS
NEUTRON FLUX
NOISE
OPERATION
SAMPLING
ELECTRONIC EQUIPMENT
ENRICHED URANIUM REACTORS
EQUIPMENT
HOMOGENEOUS REACTORS
HYDRIDE MODERATED REACTORS
IONIZATION CHAMBERS
IRRADIATION REACTORS
ISOTOPE PRODUCTION REACTORS
MEASURING INSTRUMENTS
NEUTRON DETECTORS
PROCESSING
RADIATION DETECTORS
RADIATION FLUX
REACTORS
RESEARCH AND TEST REACTORS
SOLID HOMOGENEOUS REACTORS
THERMAL REACTORS
TRIGA TYPE REACTORS
WATER COOLED REACTORS
WATER MODER
220400* - Nuclear Reactor Technology- Control Systems
440101 - Radiation Instrumentation- General Detectors or Monitors & Radiometric Instruments