Determining a physically appropriate neutron spectrum from multisphere data

Conference · Mon Apr 01 04:00:00 EST 1985

OSTI ID:5658773

Scherpelz, R I; Brackenbush, L W

The multisphere (or Bonner Sphere) spectrometer system is widely used for the characterization of neutron radiation fields due to its good sensitivity over a wide range of energies. The multisphere data must first be processed by an unfolding code to determine the neutron parameters, and this code must select the spectrum from an infinite number of mathematically correct possibilities. Recent studies have shown that the neutron spectra determined by an unfolding code can be influenced by features of the code such as the choice of initial spectra or the method of smoothing. This study further explores the characteristics of a multisphere measurement and unfolding code that can influence the calculated spectrum and its approximation of a physically realistic neutron spectrum. The use of data from another spectrometer system for setting the initial spectrum is shown to be a very promising technique for generating physically meaningful results. Other factors discussed in this study include the detector response functions and the convergence criteria and duration of iteration. The study shows that the determination of a physically appropriate neutron spectrum can only be accomplished with proper attention to these factors.

• Research Organization: Pacific Northwest Labs., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5658773
• Report Number(s): PNL-SA-12888; CONF-8505103-3; ON: DE85013045
• Country of Publication: United States
• Language: English

Related Subjects

440103* -- Radiation Instrumentation-- Nuclear Spectroscopic Instrumentation
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BONNER SPHERE SPECTROMETERS
DATA PROCESSING
FUNCTIONS
MEASURING INSTRUMENTS
NEUTRON SPECTRA
NEUTRON SPECTROMETERS
PROCESSING
RESPONSE FUNCTIONS
SPECTRA
SPECTRA UNFOLDING
SPECTROMETERS