Presentation on theme: "Contributions to Nuclear Data by Radiochemistry Division, BARC"— Presentation transcript:
1 Contributions to Nuclear Data by Radiochemistry Division, BARC Kathi SudarshanRadiochemistry DivisionBhabha Atomic Research CentreMumbai , INDIA
2 Nuclear reaction data: Users and experimentalists determining them Fission yield distribution in neutron induced fission of actinides (for nuclear data and understanding the factors influencing them)Mass, charge and angular distribution of fission products in heavy ion induced fission (understanding the mechanism of the reactions)Nuclear spectroscopyNeutron capture cross-section/gamma-ray production probabilities for analytical purposes
3 Facilities Reactors Accelerators APSARA CIRUS DHRUVA neutrons En=0-10 MeVn 5x1011 to 5x1013 n cm-2s-1f = 20 TO 150AcceleratorsBARC-TIFR Pelletron, MumbaiVariable Energy Cyclotron, Kolkatap, and heavy ionsI nA to μAE 3-8 MeV/A
4 Methodologies Radiochemical method Irradiation followed by off-line -ray spectrometryInduced activity at the end of irradiationReactor IrradiationBeam IrradiationN:Total no. of target atomsTarget atoms per unit area:Flux (neutrons.cm-2.sec-1)Intensity (particles.sec-1):Cross sectionTirr:Duration of irradiation:Decay constant of product radionuclide
5 a : Gamma-ray abundance E : Detection Efficiency Assay of gamma-ray activity after cooling time TCa : Gamma-ray abundanceE : Detection EfficiencyPeak area Activity Cross sectionParticle telescopesMonitorTargetBeamCoincident measurementsOnline charge particle measurement using E-E detectors
6 NUCLEAR FISSION STUDIES Mass & Charge distribution in neutron induced fission of Actinides238U, 237Np, Pu, 241Am, 243Am, CmOff-line gamma ray spectrometryRadiochemical separations, in some casesNucl. Phys. A 781 (2007) 1Nucl. Phys. A 612 (1997) 143J. Phys. G. 30 (2004) 107Eur. Phys. J. A 7 (2003) 495.Elemental Yields in neutron induced fission
7 Heavy ion induced fission , p induced fissionMedium heavy ion induced fission( ion beams of isotopes of Li, B, C, O, Ne…)Both online and off-line measurementsMass, charge, angular and mass resolved angular distributionsTo investigate transfer induced fissionTo understand the correlation between mass asymmetry and angular anisotropyPhys. Rev. C 71 (2005)Eur. Phys. A. 26 (2005) 1434Phys. Rev.C, 74 (2006)
8 CM AD of fission fragments in 11B+243Am reaction 20Ne+208Pb at 114 MeV Phys. Rev. C 69 (2004)024613Phys. Rev. C 75 (2007)
9 Mass distribution in 7Li+232Th Radiochim. Acta. 90(4) (2002) 185.
11 Nuclear Spectroscopic Data Gamma ray abundances of 194TlgRadio. Chim. Acta. 91(2003)1Gamma-ray abundance of capture -rays from 60CoNucl. Instr. Meth. A. 457 (2001) 180.
12 Gamma ray abundances in the Alpha decay of 229Th Phys. Rev. C. 27 (1983)327
13 NEUTRON ACTIVATION ANALYSIS Data use and determination for analytical purposesNEUTRON ACTIVATION ANALYSISFor neutron induced reactions VC=0It enters all nuclei and binds to it.CN is in excited state.PGAAA+1XNAAA+1XZ+1NEUTRON INTERACTION OFTEN PRODUCES RADIOISOTOPES : ENTIRE PERIODIC TABLECHARACTERISTIC RADIATIONS, e.g., GAMMA RAYS ARE MEASURED : CONCN. OF ISOTOPES (ELEMENTS)
14 STANDARDIZATION METHODS OF NAA Absolute methodRelative method (comparative)Ratios of count rates in standard and sampleSingle comparator (k0-method)Co-irradiation of sample with a mono standard (e.g., Au, Mn, Sc)
15 k0-methodology & Calculations Determination of and f by cadmium ratio or bare detectors: 197Au and 94,96Zrk0- factors determined as well as computedJ. Radioanal. Nucl. Chem 256 (2003) 93Anal. Chem.75(2003)4868J. Nucl. Mat 326 (2004) 80Anal. Chim. Acta 522(2004)127Appl. Radiat. Isot. 65(2007)164
16 In-situ efficiency calibration – Determination of relative amounts without use of standard Standard-less composition analysis of nuclear cladding materials: Zircaloy 2 and 4, Stainless Steel and 1S-Aluminium