Embed Size (px)
DESCRIPTION
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 [email protected] Institute for Nuclear Research NAS Ukraine Kyiv. Key concept. - PowerPoint PPT Presentation
Citation preview
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
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.
Inte
nsit
y of
neu
tron
s, r
el.u
n.
1.e-5 eV Neutron energy 20 MeV
Inte
nsit
y of
neu
tron
s, r
el.u
n.
Neutron energy 2 keV
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-pure isotopes 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
• 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.
The main characteristics … (continuation):
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
Institute for Nuclear Research NAS Ukraine
Kyiv
Technology Reference: Alexander Sich
