The Neutron Laboratory
The JEEP-II research reactor :
2 MW power, D2O moderated, UO2 enriched fuel (3.5% U-235). Operational cycle, discontinuous, depending upon the isotope production and irradiation of silicone single crystals. 8 radial beam channels and one throughgoing tangential channel with a cold moderator (liquid H2). Thermal neutron flux density in core: 2.2 x 1013 n/cm2/s Fast flux density: 1.9 x 1013 n/cm2/s
Diffractometers and spectrometers at JEEP-II:
PUS (The powder diffractometer)
Operative since 1997. Vertically focusing composite Ge monochromator. Wavelengths in the range 0.75 - 2.55 Å available from choice of Ge(H11), H= 3,5,7 reflections and monochromator take-off angles between 60-90o. Two detector-units each covering 20o in 2theta by position sensitive 3He detectors. Collimation in front of the monochromator: 15’, 30’ and open (60’). Angle-range in 2theta: up to 130o. Accessories: DISPLEX cryostat (7 K), a furnace is being built (1600 K). Neutron flux at sample (with 15’ collimation) : 0.25 x 105.
(The Small Angle Neutron Scattering Instrument)
Built in 1986, modified several times since then. Uses neutrons from a cold moderator (liquid H2), through a liquid nitrogen cooled Be-filter and a velocity selector, neutron wavelength = 5 - 9 Å. 2d-detector (sensitive area 60 x 60 cm2) in a 3 m long vacuum chamber where the distance from the sample may be varied. Q-range 0.01 - 0.25 Å-1. Neutron flux at sample 8 x 105.