Device for detecting neutrons with ionization chamber and with optical transduction comprising a plurality of optical cavities, each accommodating the free end of an optical fiber

A device for detecting neutrons comprising:

• at least one sealed ionization chamber with optical transduction, which extends along a longitudinal axis and comprises a plurality of optical cavities,
• wherein each optical cavity accommodates a free end of an optical fiber and comprises at least one inner wall coated at least partially with at least one active material, the optical cavities being filled with a gas that is able to be ionized by an ion arising from a reaction between a neutron and the active material,
• wherein each optical cavity is delimited by a cylinder that is closed at its longitudinal ends by a closing disk, the lateral inner wall of which is coated at least partially with an active material, the cylinders of the cavities adjoining one another while being centered on the longitudinal axis, at least one of the cylinders of the cavities being pierced laterally with an opening, which is configured to allow through one of the optical fibers whose free end is accommodated in an adjacent cavity.