Photonis Nuclear Instrumentation is one of the world leaders in the design and manufacture of neutron and gamma detectors, an essential element for the safety and control of nuclear reactors and critical to the safety of fuel reprocessing plants, radioactive waste storage, and nuclear research facilities.
Photonis brand has a unique detector technology compatible with different reactor types, high radiation, high temperature, high external pressure, LOCA (Loss Of Coolant Accident), and post LOCA protection.
For over 50 years, Photonis has been growing its knowledge and experience through involvement with French nuclear power plants and research programs. In the last 10 years, the Photonis customer list has grown to include Sweden, Bulgaria, China, Czech Republic, Russia, Slovakia, Switzerland, Ukraine and the USA. Today our dedicated R&D team can develop or adapt our extensive catalog of nuclear components to customer specific requirements for a variety of applications, including small modular and advanced reactors.. The Nuclear Instrumentation team is organized according to ISO9001, ISO19443 , RCCE (EDF rules), ASME NQA-1, HAF604
Need some answers? Ask our experts!
Mineral insulated extensions
Neutron and Gamma Detectors for the nuclear industry, including applications in nuclear power plants, fuel reprocessing facilities, waste storage monitoring, and nuclear research instrumentationRead more
As a neutron has no charge, a neutron detector incorporates a neutron-to-ionisation particle converter.Read more
Mineral insulated extensions
The extreme operating conditions in which Photonis neutron and gamma detectors are operating can lead organic insulated cables to deteriorate, requiring repair.Read more
Frequently asked questions
What determines usable life in a detector?
A detector is usable so long as it remains sensitive to neutrons and capable of transmitting sufficient signal to be used by the electronics. The sensitivity of the detector will gradually decrease over time as it is exposed to thermal neutron flux, and the detector will remain viable as long as the electronics allow for the decrease in sensitivity. For B-10 lined proportional counters the gas internal to the detector is vital to linear performance of the detector and is subject to degradation during operation in high radiation environments. Photonis proportional counters may include an additional reservoir of proportional gas which extends detector life (up to ~5 x 1018 n/cm2) substantially, making total lifetime greater than the life of similar detectors without this reservoir and significantly longer than BF3 counters.
What role does temperature play in detector operation?
Detector operation can be significantly affected as the ambient temperature they are exposed to increases above 400 C, by several different mechanisms. The internal gases used to ensure linear operation of the detector must be carefully chosen to ensure they can remain chemically unchanged at these high temperatures. Further, as temperature rises above 400 C the internal resistance of the detector may decrease, causing a rise in leakage current which could limit the functional range or decrease the accuracy of the detector. For these concerns Photonis has designed high temperature detectors, utilizing the appropriate gases, materials, and guard ring construction to allow accurate and reliable operation up to 600 C.
What are the differences between a thermal and fast neutron detector? Why might I use one or the other?
‘thermal’ and ‘fast’ refer to the energy level of the neutron incident on a detector. Thermal neutrons are typically defined as having energy <.025 eV. These lower energy neutrons are more likely to be absorbed by neutron sensitive materials, meaning thermal neutron detectors tend to have higher overall sensitivity. Thermal neutron detectors are designed to generate the majority of their usable signal from interactions with thermal neutrons, where fast neutron detectors are primarily capable of measuring high energy neutrons (>1 MeV). This has applications for research, where it may be important to use multiple detectors to differentiate between neutron energies, or in reactor applications where measurable neutron flux is primarily in high energy neutrons.
Why use a B-10 lined proportional counter vs. a fission chamber for neutron detection?
Each detector type offers unique characteristics which suit it to a particular application. B-10 lined proportional counters offer excellent sensitivity to thermal neutrons, allowing them to achieve sufficient count rates in low neutron fluxes. For example, this feature makes the use of B-10 proportional counters attractive as monitors during initial reactor criticality, where the increased detector sensitivity ensures that smaller, less expensive, start-up sources can be installed in the reactor core. Fission chambers, in contrast, have lower sensitivity to thermal neutrons but have superior resistance to gamma ray interference and offer the capability to operate over many decades of neutron flux. This feature makes fission chambers the ideal choice as wide range monitors of reactor power. The Photonis technical team is happy to work with customers to determine which detector type makes the most sense in each customer application.
Why do some detectors include integrated mineral insulated cabling instead of a standard connector?
Integrating a long mineral insulated cable with the body of the detector is ideal for the severe operating environments (high radiation level, humidity, vibration, high temperature) to maximize reliability and life of the instrument. Photonis recommend the use of integral cable for nuclear power applications to ensure trouble-free long-term operation. In mild environments, or in applications which otherwise do not permit integral cabling, Photonis is able to offer detectors with connection directly at the connector body.
What difference is there between coaxial and triaxial cables? How will I know which is best for my application?
Triaxial cables provide additional screening against unwanted sources of noise compared to coaxial cables- EMI/RFI interference and potential ground loops for small signals can be minimized, although this comes at a trade-off more difficult mechanical construction, lead-time, and cost. Typically, coaxial cables are sufficient for most nuclear applications but unusual, demanding, or unique applications may require the use of a triaxial cable solution. The Photonis Nuclear Instrumentation team has experience both working with our clients in determining the correct cable solution and qualifying the solution for use in industry.
What's new in Nuclear Instrumentation?See all
Nov 24th 2023
Photonis, part of Exosens, Aids in TerraPower’s Mission of Low-Cost and Carbon-Free Energy Solutions with Key Components of Operation
Feb 06th 2024
Photonis shall deliver 40,000 image intensifier tubes to boost military night vision in Germany and Belgium
KINTEX Exhibition Center Ⅱ.
FROM Sep 25th 2024 TO Jun 28th 2024
Visit Exosens at DX KOREA 2024 from September 25 to 28 in KINTEX Exhibition Center Ⅱ, Korea