Furnace or chemical reactor wall thickness measurement appts. - has fast neutron generator surrounded by reflector and scattering layers and includes thermal neutron counters

摘要

The appts. measures the thickness of furnace or chemical reactor walls using neutron beams. There is a source of fast neutrons (7) surrounded by a reflector (15) for fast neutrons, and placed against the measuring point (2) on the furnace wall. The furnace wall (3) may consist of bricks surrounded by a metallic casing (4). The neutron source (7) and detector are surrounded by a gas tight housing (5). The detector (6) consists of two pairs of counters (9,11) separated by a moderator or neutron braking layer (13). They are connected (14) to a measuring circuit contg. an amplifier (19) and a counter (21). The source (7) and reflector (15) are surrounded by pieces made of neutron scattering material. The detectors (9,11) are designed to detect thermal neutrons.