Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Preliminary tests for actinide measurements using AMS at the 1 MV Tandem accelerator D. G. PACESILA1,2, T. B. SAVA1, M. STRATICIUC1, D. G. GHITA1, V. MOSU1 * PhD Student, doru.pacesila@nipne.ro 1. Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Magurele, Romania 2. University POLITEHNICA of Bucharest, Bucharest, Romania
Department of Tandem Accelerators Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Why AMS? The most sensitive isotope selective detection method: Single ion detection capabilities High accuracy (few ‰) Huge dynamic range Extreme sensitivity Sample: Isotope ratios: 10-6-10-15 Typical size: mgμg 104millions of atoms Accelerator mass spectrometry (AMS) is a technique for measuring long-lived radionuclides that occur naturally in our environment. AMS uses a particle accelerator in conjunction with ion sources, large magnets, and detectors to separate out interferences and count single atoms in the presence of 1 x 1015 (a thousand million million) stable atoms. - important AMS radionuclides 10Be, 14C, 26Al, 36Cl, 41Ca, 129I, actinides, Half-life: 5.700 -12.700.000 yrs
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators 1 MV AMS block diagram: negative ion source; 2. electrostatic analyzer on low energy; 3. analyzing magnet on low energy; 4. Q-pole lens ; 5. tandem accelerator; 6. analyzing magnet on high energy; 7. Beam current measurement sistem; 8. 120o electrostatic analyzing on high energy; 9. gas ionization detector (E-ΔE )
AMS aplications at the 1 MV accelerator @ IFIN-HH RoAMS laboratory Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators AMS aplications at the 1 MV accelerator @ IFIN-HH RoAMS laboratory More than 500 samples measured only this year.
Stable izotops ratio / radio-izotops in nature Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Aplications of the AMS method Stable izotops ratio / radio-izotops in nature Element Izotop Abundance(%) Half-life(years) Berilium 9Be 10Be 100 0.000 000 000 1 1.39x106 Carbon 12C 13C 14C 98.9 1.1 5.73x103 Aluminium 27Al 26Al 0.000 000 000 001 Clor 35Cl 36Cl 37Cl 75.77 24.23 3.01x105 Calcium 40Ca 41Ca 42Ca 96.941 0.647 1.04x105 Iodine 127I 129I 1.70x107 Uranium 238U 235U 234U 99.275 0.72 0.006 4.47x109 7.04x108 Plutonium 239Pu 240Pu 242Pu 2.40x104 6.56x103 3.74x105 Geology Arheology/Geology/ Environment Geology /Medicine Geology Medicine /Pharmaceutical Oceanographic tracer, atmospheric and environment Environmental supervision, Nuclear Forensics
Why are important actinide measurements? Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Why are important actinide measurements? Nuclear materials Finding evidence of the source, the trafficking, and the enrichment of the material. In order to determine the production date (age dating, time since last purification) of a radioactive material for nuclear forensic and safeguards purposes, we have to be able to measure the ratios between U, Pu and Th isotopes. http://www.gao.gov/products/GAO-15-123 Environmental samples Nuclear processes emit trace amounts of material to the environment. The nuclear material can settle on equipment and surfaces within buildings and can be transported outside to deposit on vegetation and soil or reach water systems. Levels of certain fission products, Actinides and other radioactive species can be used as indicators of undeclared nuclear facilities or activities, either on-going or in the past Nuclear material is everything that contains U, Pu, Th.
Department of Tandem Accelerators Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Plutonium production UO2 fuel U isotopes - 232, 233, 234, 235, 236, 238 Plutonium isotope ratios (240Pu/239Pu) indicate the fuel burn-up Sample used: STD1/2 CNA-Pu: 239Pu/242Pu = 0,534±0,011 240Pu/242Pu = 0,281±0,005 Sample cathode
Department of Tandem Accelerators Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Experimental Set-up Isotopes Rare isotopes 239Pu, 240Pu, 242Pu Stable isotopes no stable isotopes Ion source Sample material PuO Target voltage 7kV Extraction voltage 28 kV Ionizer current 18 A Cesium temp 100o Bouncer injection Injected beam PuO- ESA 3.921 kV for 35 keV X slit 1(esa) 5mm Magnet current 238UO16 Bounced masses 1. 255 AMU 2. 256 AMU 3. 258 AMU Bouncer voltage 1) 137 V 2) -273.4 V 3) -542.9 V X slit 2(magnet) 3mm Accelerator Injected masses 1. 239 AMU 2. 240 AMU 3. 242 AMU Terminal voltages 1) 576.5 kV 2) 575.5 kV 3) 568.99 kV Stripper gas 6 μbar High energy spectrometer Charge state 3+ Yield 20% Magnet current 380 A for 240Pu Rare isotope beam line X slit 5 mm ESA voltages 1) 29.735 kV 2) 29.610 kV 3) 29.319 kV ESA exit slit fully retracted Detector Entrance window 75 nm silicon-nitride Pressure 6.0 mbar
Department of Tandem Accelerators Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Results channel counts channel counts 242Pu channel counts channel counts 240Pu channel counts channel counts 239Pu
Department of Tandem Accelerators Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Results channel counts 240Pu 160Dy E. Chamizo et al., Nuclear Instruments and Methods in Physics Research B 266 (2008) 4948–4954 Isotopic Ratios 1 MV @ IFIN-HH 239Pu/242Pu = 0,5942 240Pu/242Pu = 0,2313 sTD CNA-Pu 239Pu/242Pu = 0.534 240Pu/242Pu = 0.281 E.C. Calvo et al., Nuclear Instruments and Methods in Physics Research B 361 (2015) 13–19
Conclusions and future perspectives Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) Department of Tandem Accelerators Conclusions and future perspectives The 1 MV HVEE AMS facility has been set-up for the measurement of plutonium isotopes. In terms of detection limits and optical transmission through the accelerator, the system compares to the other compact AMS facility ; These results are very encouraging regarding the measurements of other actinides (236U,234U, 232Th,). Our future prospects are: Study of the sample preparation techniques; Improvements on the performance of the ion source and on the detection setup; Implementation of the He gas as stripper for a better transmission.
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