The Neutron Detector Service (SDN) of the ILL has two principle objectives :
- to ensure that the detectors of the Institute and their analogue electronics function well.
- to develop new detectors that can be tailored to meet an instrument's individual requirements :
the demand on detectors has increased dramatically during the last years, not only in performance, but also in production capability.
MSGC, MWPC and Multi-tube detectors cover most of the experimental conditions of intense neutron sources:
- MSGC are now considered as a fully commissioned technique for neutron instrumentation, but their main drawback is their limited size, about 25 cm x 25 cm for one single piece. This technique is used on both the D4C and D20 powder diffractometers.
- MWPC is a very appropriate choice when larger 2-dimensional detectors are needed without dead space. In 2002, we have started the development of a 2D curved vessel MWPC for D19 with an angular coverage of 120° horizontally and 30° vertically. This detector is operational since 2005.
- The Multitube (patent pending) is made of identical tubes brazed side by side on both ends to a common pressure vessel. The position along the tubes is measured by charge division. Prototypes with different sizes of tubes, from 3000 mm long, 25 mm diameter, to 250 mm long, 4.5 mm diameter, have been successfully tested in view of modernizing several instruments of the ILL. This new gaseous detector has been developed to respond to the demand of cost effective, very large area, fast detectors. The IN5 chopper spectrometer will be equipped in 2008 with 12 Multitube modules, covering a total sensitive area of 30 M2.
- The SDN participated, in the framework of the FP6 program, to the MILAND international project, which aims at developing a 2D fast detector with a 32 cm x 32 cm sensitive area, and a 1 mm position resolution.
Head of service: Bruno Guerard