Neutron Guide System at Channel R2 of HOR in Interfaculty Reactor Institute (Netherlands)

Entrance of the neutron-guide system.

Exit of the neutron-guide system.

The IRI Neutron Guide System in beam tube R2 of the HOR is designed to transport neutrons to the Experiment Hall adjacent to the reactor building, where the instruments using the neutrons will be installed. The system consists of 4 neutron guides: three large guides and one small guide. The large neutron guides are identical and have a cross-section of 21.5x80 mm2. The small neutron guide has a cross-section of 5.5x40 mm2. Neutron guides look at the core end of the beam tube, which has a diameter of 200 mm, from a distance of 1 m. All inner surfaces, both horizontal and vertical, are coated with NiMo/Ti supermirrors on the glass substrate. Calculated final flux intensity at the exit of system, integrated over all spectrum wavelengths, as well as fluxes measured by mean of gold foil activation are collected in the Table. Flux intensities measured by gold foil activation showed a quite good correspondence to the calculated values.

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Neutron flux at the exit
of System III [sm-2 s-1]
Neutron guide cross section [mm2] (Number of channels)

Radius of curvature [m]
Reactor power
Calculated Measured System I System II System III
A 4x10-7 3.5x10-7 5.5x40 (1)
5.5x40 (1)
5.5x40 (1)
2 NiMo/Ti
B, C, D 3.9x107 3.6x107 5.5x80 (3)
5.5x80 (3)
5.5x80 (1)


Contact person: Mr. H.P.M. Gibcus,
Manager of Interfaculty Reactor Institute
Interfaculty Reactor Institute (IRI)
TU Delft,
Mekelweg 15, 2629 JB Delft
The Netherlands
Phone: + (31) 15 2784802
E-mail: H.P.M.Gibcus@IRI.TUDelft.NL