Sahagia_Main Research Area.ppt

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Sahagia_Main Research Area.ppt

  1. 1. Main Research Area and International Activities of the Radionuclide Metrology Laboratory from IFIN-HH Maria Sahagia “Horia Hulubei” National Institute of Research and Development for Physics and Nuclear Engineering, IFIN-HH, Bucharest, Romania Second workshop for radioactive Decay Data Evaluators, DDEP 2008 Bucharest, Romania, May 12 – 14, 2008
  2. 2. Subjects to be treated • General presentation of the Radionuclide Metrology Laboratory (RML) • Main research areas • International cooperation of RML
  3. 3. History •IFIN-HH was founded, under the name of “Institute for Atomic Physics”, in 1949. •Name IFIN was given in 1977, what became IFIN-HH (Horia Hulubei) in 1996. • Radionuclide Metrology Laboratory (RML) was created in early sixties. The founder is Dr. Enric Leon Grigorescu.
  4. 4. Official Status of the Laboratory • Absolute (primary) standardization in the field. • 2005-Protocol, National Metrology Institute (NMI) -Romanian Bureau of Legal Metrology (BRML) and IFIN-HH: - IFIN-HH - owner of the Primary Standard of Activity Unit (Becquerel) and derived units - BRML designated IFIN-HH: participant in International Committee for Weights and Measures - Mutual Recognition Arrangement (CIPM-MRA) ionizing radiations, CIPM-MRA, Annex A. - BRML appointed IFIN-HH: representative in the Technical Committee for Ionizing Radiations (IR-TC) of EURAMET (EUROMET) • BRML authorizes RML for legal metrology activities and attests it , as a calibration laboratory
  5. 5. Infrastructure and personnel RML- part of the IFIN-HH Radioisotope Department (RD) - Facilities for safe operation of sealed and open radioactive sources: radiochemistry laboratory, a balance room, two measurement laboratories, auxiliary rooms; - Separation from the RD crossing activities. Climatic regime and radiation background control-recently improved. - As a part of IFIN-HH, RML has access to all the available facilities, library, computing and communication network •RML Staff: 5 permanent and 1 associate members 2 PhD, 1 PhD student, 1 Scientific researcher, 1 young physicists, 1 technician. Thanks are due to Dr. E.L.Grigorescu, who retired.
  6. 6. Main research areas • Methods and equipment for absolute standardization • Methods and equipment for spectrometry and for relative standardization • Methods and equipment for preparation of radioactive sources • Metrology services and assurance of traceability
  7. 7. Absolute standardization: • 4πPC-γ coincidence method • Liquid Scintillation Counting
  8. 8. 4πPC-γ coincidence method Standardization of radionuclides emitting several coincident radiations and of pure beta emitters, by the tracing method. - First system, manually operated, constructed during sixties, contains a home made Proportional Counter (PC) - flow type, pure methane , and a NaI(Tl) detector. -Electronics is NIM modular of types Nuclear Enterprises and Canberra. The method and equipment were verified in international comparisons X, gamma - X, gamma coincidence detection block - two thin NaI(Tl) detectors - standardization of 125 I, M. Sahagia et al. Appl.Radiat.Isot.3986/2008, under print.
  9. 9. Main Romanian contribution in the development of the method (i) Dead time and coincidence resolution time corrections, E.L. Grigorescu, Mesucora Congress, Paris 1963; (ii) Measurement of beta, electron capture-gamma emitters, by the efficiency extrapolation: E.L. Grigorescu, Nucl.Instrum.Meth. 112(1973)151 ; E.L.Grigorescu, et al. Nucl. Instr.and Meth A369(1996) 414- 420 and subsequent papers; (iii) Efficiency tracer for pure beta emitters and extrapolation for emitters with transition to the ground level. M.Sahagia, Marianske Lazne , Symp., 1979, Proc., 2/5, pp.180-187, and followings; (iv) Standardization of special radionuclides, 99m Tc, M.Sahagia, Appl.Radiat.Isot. 64(2006)1234-1237.
  10. 10. New coincidence system • The Research project, supported - Romanian National Authority for Scientific Research (ANCS), 2006-2008, • New 4πPC-γ coincidence system: a Proportional Counter, two NaI(Tl) detectors and new electronic modules, ORTEC type or home - IFIN-HH made, operated in a semi automatic regime - constructed, is under testing : C.Ivan et al. IFIN-HH Internal Rep. 2007. • Thanks are due to the Bureau International des Poids et Mesures (BIPM), ENEA (Italy) and Laboratoire National “Henri Becquerel” (LNHB) from CEA- Saclay, France, for their help in designing the new system.
  11. 11. Liquid Scintillation Counting •Liquid Scintillation Counter, principle of the Triple to Double Coincidence Ratio (LSC-TDCR): Detection block with three photomultipliers and associated electronics • Contribution of the LNHB-France and RC-Poland LSC-TDCR method implemented, and the system used for standardization of : H-3, C-14, P-32, Ni-63, Sr-89, Tl- 204, Am-241, Cs-137, Fe-55 •Method and system - verified by bilateral or key comparisons. A.C. Razdolescu and P. Cassette, Appl. Radiat. Isot. 60 (2004) 493-497; A.C. Razdolescu, et al, Appl. Radiat. Isot. 64 (2006) 1510-1514.
  12. 12. ANCS project – LSC improvements under way: (i) New photomultipliers, type Burle 8850 (ii) A new detection block with 6 Channel Photomultipliers (CPM) (iii) A NaI(Tl) probe for the application of the 4πLS-γ coincidence method. (iv) The LabVIEW operation software - under installation.
  13. 13. Methods and equipment for spectrometry and for relative standardization • Spectrometric methods • Equipment and methods for relative (secondary) standardization
  14. 14. Spectrometric methods - Traditional work: GeHP gamma-spectrometer of the RD - Contribution in development of the spectrometry method: (i) Use of the coincidence and Compton suppression anticoincidence for the low level activity measurements. E.L.Grigorescu, Nucl.Instrum.Meth. A 369 (1996) 574-577; A. Luca et al., Appl. Radiat. Isot. 53 (2000) 221-224; E.L. Grigorescu et al., Appl. Radiat.Isot. 61 (2004) 191-195; (ii) Studies on the shape of the gamma-ray background under the total absorption peaks, A.Luca et al., Appl.Radiat.Isot. 60 (2004) 233-237; (iii) Measurement of the X- and gamma-rays emission intensities for Zn-65, Sb-124 M.M.Be, ICRM2005, Appl.Radiat.Isot. 64 (2006)1396;
  15. 15. Content of the system Three detection blocks: (i)Gamma-ray detector: coaxial HPGe type, ORTEC model GEM-25P4, relative efficiency 30% (60 Co); resolution 0.62 keV for 122 keV and 1.67 keV at 1333 keV; energy interval: 30 keV - 3 MeV. Shield: old lead, copper and a 1 mm thick tin foil - under construction (ii) X-ray detector - Si(Li), CANBERRA : energy interval 1 keV-50 keV, resolution 166 eV at 5.9 keV (iii) Alpha spectrometry chamber - surface barrier silicon detector, and vacuum system. All the three detection blocks are compatible (or adapted) to the analysis system, ORTEC, consisting from a digital spectrometer, connected to a personal computer.
  16. 16. Software facilities : ORTEC GammaVision-32 (Model A66-B32), version 6.01, Advanced Measurement Technology, Inc. (AMETEK), USA; ORTEC MAESTRO-32 (Model A65-B32), version 6.06, Advanced Measurement Technology, Inc. (AMETEK), USA; GESPECOR, Romanian (Prof. O. Sima) - German (Dr. D. Arnold) - calculation of coincidence summing corrections and transfer of efficiency calibration between various geometries and matrices.
  17. 17. Equipment and methods for relative (secondary) standardization Well-type ionization ionization chamber CENTRONIC IG12/20A Transfer instrument, for secondary standardization of radioactive sources and solutions.
  18. 18. Calibration of the chamber. Calibration figures were assigned for Various Gamma emitters and various geometries (i)High activity sealed sources: certified by other producers - 241 Am, 137 Cs, 60 Co. (ii)Solutions vials: 2ml , PTB, Germany; 3.6 ml, BIPM - SIR; 5 ml , for radiopharmaceuticals; response is dependent of the volume of solution, mainly for low energy gamma-rays emitters.
  19. 19. Calibration for solutions •Calibration with solutions absolutely standardized in RML by 4πPC-γ coincidence method , for 17 radionuclides: 54 Mn, 57 Co, 65 Zn, 99m Tc, 124 Sb,131 I, 133 Ba, 134 Cs, 137 Cs, 152 Eu, 153 Sm, 169 Yb, 177 Lu,186 Re,188 Re, 192 Ir,241 Am. Uncertainty, U, for k = 2: U < 1.0% ( 2.1% for 99m Tc) •10 radionuclides: 54 Mn, 65 Zn, 131 I,133 Ba, 134 Cs, 137 Cs, 152 Eu, 169 Yb,192 Ir, 241 Am, verified in Key comparisons. RML values compared with calibration figures assigned, according he Key Comparison Reference Values (KCRV). Maximum difference: 241 Am (1.1%) •Calibration performed in 2001 at PTB, Germany, by Dr. H. Schrader, A.Luca and Al. Druker (NMI), using PTB - 2ml vials with standard solutions, for 19 radionuclides, 11 being common. PTB - IFIN-HH comparison : results agreed within uncertainties. •Special attention for 131 I , Sahagia et al. ARI 66(2008)539-544
  20. 20. Improvement of the electrometric system of the chamber • Traditional electrometric system : a set of 0.1 nF, 1nF, 10 nF and 100 nF capacitors. - Separate calibration figures, expressed in, mV s-1 MBq-1 for the capacitors, had to be determined, to be used for various activity intervals. • Since 2006, an electrometer type Keithley 6517A has been operational. - Parallel registrations, with both electrometers, and precise determination of the capacitors values - performed . - The capacitor , 1 nF - value was determined with an uncertainty uc = 0.15%. • The calibration figures were transferred to the new units, pA MBq-1 .
  21. 21. Large area multiwire, sealed proportional counter • Used for large surface alpha and beta sources used for measurement of surface contamination. • Calibration - performed in terms of activity and particle emission rate in 2πsr geometry. - calibration in activity was performed by using standard sources, gravimetrically prepared from 147 Pm, 204 Tl, 90 (Sr+Y) standard solutions - emission rate calibration is made using sets of sources measured directly in the upper half of the proportional counter. - response values - determined for various source dimensions, up to 250 mm x 250 mm. M.Sahagia et al. Proceedings, IRPA 9 Congress, 1996, vol 3, pp.34-36 Vienna, Austria  
  22. 22. Methods and Equipment for preparation of radioactive sources • Sources and solutions for absolute (primary) standardization - Radioactive solutions and gravimetric dilutions for other solutions. - Sources for absolute standardization: solid VYNS sources for coincidence method and LSC vials. - Traditional work: a METTLER M5 micro and an analytical balance. - Recent purchase: a set of METTLER TOLEDO certified balances, types: MX/M (micro) and XS204/M. • Radioactive standards for users - various types of radioactive solutions - solid radioactive sources, covering the main part of Romanian necessities: alpha spectrometric sources, large area beta sources sets of gamma sources, of types: (i) point sources; (II) volume solid sources, with matrices: water equivalent, soil, zeolite for various volume samples measurement. M.Sahagia et al. ICRM1991, Nucl.Instr. And Meth. A312(1992)236-239
  23. 23. Metrology services and assurance of traceability: • Organization of national comparisons - Environmental type, mononuclide samples, 2 comparisons, 134 Cs, 137 Cs, 152 Eu, M.Sahagia et al. Nucl. Instr. And Meth. A339(1994)38-42 - Radiopharmaceuticals: 131 I (1994 and 2007), 57 Co (1998), 99m Tc (1998 and scheduled 2008). M.Sahagia et al. Proceedings, IRPA9 Congress, 1996, Vienna, Vol.3 pp.497-499 • Metrology services As a B RML authorized and attested laboratory, RML performs - legal metrological check and calibration of equipment - standardizes radioactive sources for users (RML products, or imported). • Accreditation by the national body, RENAR. - whole documentation for accreditation - submitted to RENAR - pre-assessment evaluation , according to EN ISO/IEC 17025-2005, by Mike J Woods, IRMC Ltd., U.K. - RENAR evaluation of the documents and implementation - this year. - process is under way, with the accomplishment of corrective actions.  
  24. 24. International cooperation • Participation at international comparisons for absolute and relative standardization • Membership in international organizations • Bilateral and multilateral projects
  25. 25. Participation at international comparisons for absolute and relative standardization • BIPM comparisons since 1962 - 60 Co sources. • Adoption of the CIPM-MRA (Mutual Recognition Arrangement) and establishment of the Annex B, Key Comparison Data Base (KCDB), RML is part of the program. • Key comparisons registrations: (i) BIPM.RI(II)-K1: 110m Ag, 133 Ba, 60 Co, 134 Cs, 131 I . (ii) CCRI(II)-K2: 241 Am, 109 Cd,139 Ce, 134 Cs,137 Cs, 152 Eu, 55 Fe, 125 I , 192 Ir,54 Mn, 32 P, 75 Se, 89 Sr,204 Tl, 65 Zn. (iii) EUROMET RI(II)-K2: 169 Yb , 124 Sb (under analysis) • Supplementary comparisons, organized by the IAEA CCRI(II)-S4 “Radionuclides activity measurement in environmental samples of water, soil and grass” (2006); CCRI(II)-S5 “TENORM” (2007); CCRI(II)-S6 - 131 I (2006) and 57 Co (planned 2008)
  26. 26. Conclusions from comparisons • Classification of results: - Very satisfactory results- our result being considered for the calculation of the KC Reference Value (KCRV), 60 Co, 152 Eu,192 Ir, 133 Ba,131 I ( SIR 2007- 2009 approval); results with small deviation from the mean: 54 Mn, 65 Zn, 55 Fe, 204 Tl - Good results, registered in KCDB, but not in KCRV (134 Cs, 241 Am) - Not satisfactory - 125 I. We identified the error sources and developed a new, coincidence, standardization method. • The program allowed us: - to validate our methods for absolute and relative standardization, - to establish the equivalence of the primary Romanian Activity standards at the level of the CIPM-MRA, - to promote 37 Calibration and Measurement Capability (CMC) files, for radioactivity, which were approved by all Regional Metrology Organizations
  27. 27. Membership in international organizations •IFIN-HH - Member of the International Committee for Radionuclide Metrology (ICRM) since 1980 - RML participated regularly, starting with 1991, at ICRM conferences and presented scientific papers. - Dr. Enric Leon Grigorescu served as ICRM - Vicepresident, during 1990 -1994 -Dr. Maria Sahagia is in the nominating commission, 2001-2009. Recognizing the active participation in international comparisons and RML publication list • The Consultative Committee for Ionizing Radiations, Section Measurement of Radionuclides [CIPM-CCRI(II)], accepted IFIN- HH, as a full member, in 2004, besides other 18 Metrology Institutes and 8 Observers In this quality, we presented reports at the 2005 and 2007 meetings and updated regularly the publication list.
  28. 28. Bilateral and multilateral collaboration Bilateral: CEA-DIMRI(DETECS/LNHB)-France PTB-Germany ENEA- Italy Multilateral: EC of Excellence – IDRANAP IAEA- CRPs
  29. 29. Bilateral projects • Collaboration with LNHB-France Collaboration Agreement, concluded by the CEA-DIMRI (DETECS)/ LNHB – France and IFIN-HH, 1993, in force until 2010 Very fruitful, all IFIN-HH, RML members worked in the LNHB and French colleagues in IFIN-HH. Common papers published: -X and gamma-ray spectrometry: A. Luca et al., Appl.Radiat.Isot. 52(2000)481-486, 56(2002)173-180, 58(2003)607-610; Appl.Radiat.Isot. 60(2004)233-237 - LSC-TDCR: A.C. Razdolescu and P. Cassette, Appl.Radiat.Isot. 60(2004)493-498; -gas and LSC counting: D. Stanga et. al., Appl.Radiat.Isot. 64(2006)1203-1206, P. Cassette, M. Sahagia et al., Appl.Radiat.Isot. 64(2006)1465-1470; -LSC-TDCR using channel photomultipliers: C. Ivan et al., ICRM2007, Capetown, SA, Appl.Radiat.Isot. ref 4007. New directions developed at RML: LSC-TDCR method, Tritium gas measurement, High performance gamma- ray spectrometry and Nuclear Decay Data Evaluation, Radon standardization, Use of CPMs for LSC-TDCR.
  30. 30. Bilateral collaboration-continued • IFIN-HH, RML benefited of a common calibration of the CENTRONIC IG12/20A Ionization Chamber at PTB-Germany, in 2001 • Collaboration with ENEA- Italy was accomplished by three ENEA fellowships, 2001- 2002: Source preparation, Coincidence counting, Surface sources measurement.
  31. 31. Multilateral projects • European Commission’s Center of Excellence InterDisciplinary Research and Applications Based on Nuclear and Atomic Physics (IDRANAP), Contr. ICA1- CT-2000-70023/12. - Radionuclide Metrology Laboratory participated as the WP 7 - RML members worked mainly at LNHB, on thematics: Decay Data evaluation, LSC-TDCR, Gas counting. - Colleagues from LNHB-France, RC POLATOM-Poland, ENEA-Italy, Institute of Hungarian Academy -Center Debrecen, worked in RML, in the fields: LSC-TDCR, Coincidence counting, Positron emitters obtaining and standardization. - RML members and his visitors had an important scientific contribution at the Conference: Applications of High Precision Atomic and Nuclear Methods (HIPAN 2002 ) Neptun, Romania, 2002: 9 participants from WP7, 9 papers presented-published in Conference Proceedings, Romanian Academy Editor, 2005
  32. 32. Multilateral Projects - continued • International Atomic Energy Agency (IAEA) Coordinated Research Projects (IAEA-CRP) - CRP E2.10.05 “Harmonization of quality practices for nuclear medicine radioactivity measurements” Contract ROM/12921/ 2004-2008 “Assurance of traceability, IAEA, IFIN-HH, hospitals, for nuclear medicine measurements”. RML contribution - Participated at : two international comparisons 131 I, 57 Co (under way) - Organized a national (2007) and an international (2008), Ankara-Turkey University-Medical Faculty131 I comparisons; 99m Tc comparison - 2008 scheduled; - Participated at IAEA-TRS 454/2006,Quality Assurance for Radioactivity Measurement in Nuclear medicine and other documents’ elaboration. - CRP F42.006 „Updated Decay Data Library for Actinides” Contract ROM /13341/2005-2008: „Improved decay data for important actinides”, with details to be presented by Dr. Aurelian Luca
  33. 33. Conclusions • The Radionuclide Metrology Laboratory developed methods and equipment for absolute standardization • RML assured the whole traceability chain by offering radioactivity standards and metrology services to Romanian users. • RML has a long tradition of participation in international activities • RML validated its standards by participating in international programs of comparisons THANK YOU!

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