STCU Workshop "From Science to Business" 11 – 12 October 2006, Kyiv Olena Gritzay 380 44 5253987

1. Neutron Filtered Beam Technique At Kyiv Research Reactor For Scientific And Technological Purposes STCU Workshop "From Science to Business" 11 – 12 October 2006, Kyiv Olena Gritzay 380 44 5253987 ogritzay@kinr.kiev.ua Institute for Nuclear Research NAS Ukraine Kyiv

2. Key concept • The general idea of neutron filter technique is the transmission of reactor neutron spectrum through the thick layers of materials (up to 2 m), which nuclei have the deep interference minimums in total cross section of neutron interaction with nuclei • Through these minimums the neutrons transmit and form rather narrow (in energy) quasi-monochromatic filtered beams

3. The typical view of neutron filter at reactor horizontal experimental channel. 1 – reactor core, 2 – beryllium reflector;3 – horizontal channel tube; 4 – beam shutter disks; 5 – preliminary collimator; 6 – filter-assembles; 7 – filter components; 8 – outside collimator. 1013 n/cm2s 105 n/cm2s 1014 n/cm2s 108 n/cm2s

4. Opportunities: The main tasks for scientific research • High precision measurements (0.1-0.01%) of total and partial cross sections • Precise measurements (to 1 %) of neutron cross sections, the getting of averaged nuclear parameters • Measurements of neutron capture gamma-spectra • Measurements of inel for the first exited levels of heavy nuclides • Measurements of activation cross sections

5. Opportunities: The main tasks for applied investigations • Prompt Gamma-ray Activation Analysis (PGAA) • Development of standard fluxes for reactor-dosimetry purposes • Energy calibration of proton recoil counters • Neutron radiography and tomography • Bio-medical investigations • Neutron and Boron-neutron capture therapy

6. Neutron filters used at the KRRfor fundamental investigations

7. The set of natural elements and high-pureisotopes that were used for neutron filters development: • Natural elements: Si, Al, V, Sc, S, Mn, Fe, B, Ti, Mg, Co, Ce, Rh, Cd, LiF. • High-pure isotopes: 52Сr (99.3), 54Fe (99.92), 56Fe (99.5), 57Fe (99.1), 58Ni (99.3), 60Ni (92.8 – 99.8), 62Ni (98.04), 80Se (99.2), 10B (85), 7Li (90).

8. Photograph of filter

9. Neutron filter technique allows to extract from white neutron reactor spectrum a neutron line with certain energy. Merits • Neutron line with energies from thermal to several hundred kilo-electron-volts • High intensity 106 – 108 n/cm2s Demerits • Presence of parasitic energy lines in filtered neutron spectrum • High price of high-pure isotopes

10. The main characteristics of this development are in following : • Neutron filter technique at KRR has been developed for more than 20 years, the large experience has been accumulated. • Filtered beams are very intensive. Flux is in the range 105 -108 neutrons/s*cm2. • There are very few neutron sources in the world with such intensive beams in kilo-electron-volt energy region.

11. The main characteristics … (continuation): • Such intensities give the possibilities for very precise and unique measurements. • We have at ours disposal rather large quantities of high-pure (stable) isotopes (52Cr, 54,56,57Fe, 58,60Ni, etc). • For this reason we may form the filters with very high intensities and good quality.

12. Resources &proposal • Precise measurements of total, scattering and capture cross sections at KRR using NFBT • Assistance in development of neutron filters with main component from natural elements

13. Contact information Olena GRITZAY Tel 380 44 5253987 ogritzay@kinr.kiev.ua Institute for Nuclear Research NAS Ukraine Kyiv Technology Reference: Alexander Sich alex.sich@stcu.int