3He Filled Neutron Detectors Designed for High Efficiency and Sensitivity

Reuter-Stokes brings more than half a century of design and manufacturing expertise to its neutron detectors for gross counting neutron and neutron porosity detection in LWD and wireline applications. We offer proven performance in terms of:

  • Reliability: More than 67,000 He3 filled neutron detectors deployed over the past 50 years.
  • Precision: Propriety 3He purification techniques, gas.
  • Customizability: Our team designs detectors in a range of sizes, gas mixtures, electrical terminations, and mechanical interfaces to suit a variety of downhole needs.
  • Catalog configurations
    • Drilling application sensors from 0.75 in. to 1.00 in. diameter
    • Wireline application sensors from 1.00 to 2.50 in. diameter
  • Customized He3 neutron detectors
    • Available in a range of sizes, fill pressures, gas mixtures, electrical terminations and mechanical interfaces
    • Built in-house at our Twinsburg, Ohio, manufacturing facility
  • 3He consulting and storage
    • Guidance on sourcing and shipping
    • Safe storage with Reuter-Stokes
Neutron Scattering Product Portfolio
Position Sensitive Detectors (PSDs)

Reuter-Stokes offers 3He-filled position-sensitive proportional counters, otherwise known as Position Sensitive Detectors or PSDs, and standard 3He detectors for the neutron scattering industry. These Reuter-Stokes detectors, used in neutron scattering facilities throughout the world, have become the industry’s benchmark neutron detectors, providing scalable solutions for every instrument from SANS to Time-of-Flight.

Precision Performance 

3He purification techniques and manufacturing process control ensure the precise matching of operating characteristics among large batches of counters. This allows parallel operation of numerous detectors without the need to separate power supplies.

Position Sensitive 

Our PSDs use a highly resistive anode of nickel-chrome, which helps determine the positioning of the neutron event along the anode. Position resolution is typically 2.5mm to 5.0mm, and the charge division method of determining position resolution is recommended. It is important to properly match the detector preamplifier amplifier electrical characteristics to determine accurate position resolution.

Product Configurations 

Proportional counters are available in diameters of 0.5” to 2.0” and sensitive lengths of 4.0” to 120.0”. Construction can be either 304 stainless steel or 1100 aluminum.

Specifications - (Please note that this is a sample specification of one of over 10,000 PSD designs we have manufactured. Please contact us if your neutron detector application requires modification of the specifications given here.)


  • Maximum diameter: 1.32 cm
  • Maximum overall length: 71.3 cm
  • Connectors (2) type: MHV
  • Net weight: 0.5 kg


  • Outer shell: 304 Stainless Steel
  • Insulation: Alumina ceramic
  • Anode: Nickel-chrome
  • Neutron sensitive material: 3He
  • Fill pressure: 10 Atmospheres


  • 10 pf

Resistance @ 25°C

  • Detector: 1012 ohms
  • Anode (@140 ohms/in): 3900 ohms

Maximum Ratings

  • Voltage: 2500V
  • Temperature: 100°C

Typical Operating Characteristics

  • Voltage range: 1200-1800 volts
  • Energy Resolution (FWHM): 10-12%
  • Position Resolution: 2.5-5 mm (see note)
  • Note: Position Resolution is greatly dependent on electronics used.
Data Acquisition Systems

Reuter-Stokes offers the NeuAcq* Electronics System, the next-generation data acquisition electronics system for neutron scattering. NeuAcq* provides superior speed and accuracy for time-stamping and processing neutron events. 

NeuAcq* is a Linux and Ethernet-based system with Precision Time Protocol (PTP), Power over Ethernet (POE), and standard TCP/IP network communications to stream high-count rate neutron event data. 

Compliant with the ADARA communication protocol, NeuAcq* supports the EPICS control system and is compatible with Mantid visualization and data processing software.

Neutron Detector Modules

For your turnkey neutron scattering needs, Reuter-Stokes offers a 3He detector 8Pack that combines high-efficiency neutron detection with high-speed electronics in a sealed enclosure

This 8Pack offering delivers the added benefits of NeuAcq* Electronics in an easy-to-install 8Pack module. 

The 8Pack enables cutting-edge science in all-vacuum, partial-vacuum and non-vacuum instruments.

psd 8pack

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