ROSPEC – Rotating Neutron Spectrometer


ROSPEC is a user friendly, unique rotating neutron spectrometer designed specifically for the spectral measurement of degraded fission neutrons, which may be encountered in nuclear power and fuel processing plants, weapons-related military facilities and accelerator laboratories. Introduced in 1992, ROSPEC has a proven operational record with a program of continued performance upgrades.

ROSPEC is intended for use by non-specialists for the characterization of neutron fields that pose a health threat. It will generate very accurate spectral and dosimetric data simply and routinely in minutes or hours, in contrast to previous methods that could take weeks or months of a specialist’s time.

Data analysis is via a notebook computer, with on-line display of individual or all counter pulse height distributions, and an unfolding program for generation of neutron spectra. Kerma, maximum dose equivalent and ambient dose equivalent H*(10) and dose rate are calculated, and data storage is to hard disk. The rotating platform carries all detectors and electronics. Individual counters are removable for use in confined spaces (one 8 meter umbilical cable is supplied).

  • Generates spectral data simply and routinely in minutes/hours
  • Calculates dose (fluence) and dose rate in kerma, maximum dose equivalent (NCRP) and the ambient dose equivalent (H*(10)), from thermal to 4.5 MeV
  • On line display of individual/all counter pulse height distributions
  • Turn-key system includes counters, associated electronics, cabling, notebook PC, UPS battery backup and all software
  • Specified in NATO operational manual for military alliance research
  • Units are at work in Defence Departments in Canada, Germany, France and the USA, at US DOE sites, major fuel fabricator/reprocessors in Europe and Japan and standards labs (NIST, JAERI, CEA) around the world.

In addition to providing an in-house calibration of the ROSPEC using reference standards that are tracable to the SI through the National Research Council of Canada (NRC) or the National Institute of Standards and Technology (NIST), BTI can offer a calibration of the ROSPEC at NIST.

The NIST calibration involves the use of bare and D2O moderated Cf neutron fields (fast neutron). A short report indicating that the ROSPEC measured the dose within a certain percentage and a comparison of spectra is provided.

Note that BTI requires a two month lead time for the NIST reservation.

Technical Specifications

  • Detector Type Spherical, Gas Proportional
  • Detector Size 1 of 15 cm (6") diameter, 5 of 5 cm (2") diameter
  • Energy Range Thermal to 4.5 MeV
  • Resolution <10% at 1.0 MeV
  • Min/Max Fields Background to 100 mrem/hr (1 mSv/hr)
  • Gamma Rejection > 100:1
  • Amplifier Type Charge Sensitive
  • Amplifier Shaping TC 10 microseconds
  • ADC Type 6 successive approximation ADCs
  • Non-linearity < 0.03%
  • No. of Channels 256 per detector
  • Maximum Count Rate 1000 counts per second
  • HV Supply Voltage 1.5 to 4.0 kV (detector dependent)
  • HV Supply Ripple < 20 mV p-p
  • Data Acquistion Laptop Computer (provided)
  • Operating Systems Windows XP, Windows 7
  • Communications RS-422 converted to USB
  • Distance from Data Acquistion 23 m (75 ft) cable provided
  • Mechanical Configuration Rotating platform carries detectors and all electronics
  • Weight ~23 kg/50 lbs (excluding computer)
  • Size 41 cm (16") diameter x 60.5 cm (23.75") high
  • Input Power 110 V 50/60 Hz (220 V to 110 V step down transformer available)
  • Battery Backup UPS (provided), ~1 hr run time