Reactor dosimetry with niobium

The main advantages of using niobium in reactor dosimetry are briefly summarized. Some experimental aspects and complications of niobium dosimetry are discussed. Special techniques can be applied to overcome most of these problems. Particular concern has to be given to the detector calibration for the X-ray measurements. The main problem however, embrittlement of pure niobium under intense neutron irradiation, is still not solved. For this purpose a new type of material (Al-10%Nb alloy) was prepared. Although testing of this material is still ongoing, preliminary results are promising. This material moreover does not necessarily require applying special techniques for the X-ray measurements. Finally it is explained that niobium is a suitable material for the determination of thermal and epithermal fluences in high flux environments.