Abstract：The analysis and comparison of the geometric parameters, the correction factors and the method to determine the correct factor of 137Cs air kerma primary standard which participated the 137Cs air kerma key comparison BIPM RI (I)-K5,organized by International Bureau of Weights and Measures (BIPM) , will provide useful reference about the design in ionization chamber, the measurement of correction factors and the method of simulation for our national primary standard of air kerma for 137Cs gamma-rays.
［1］Perroche A M, Boutillon M.Comparisons and calibrations at the BIPM (1993-1995) ［C］//Document CCEMRI(I)/95-2, submitted to the 12th Meeting of the CCEMRI,1995.
［2］Loftus T P, Weaver J T.Standardization of 60Co and 137Cs gamma-ray beams in terms of exposure ［J］.J Res Natl Bur Stand(Sect A),1974, 78A:465-476.
［3］Witzani J, Leitner A, Air kerma standard at the BEV for 137Cs rays ［J］.Radiat Prot Dosim, 1996, 67, 291-294.
［4］Kessler C, Allosy-Roberts P J, Steurer A, et al.Comparison of the standards for air kerma of the BEV and the BIPM for 137Cs gamma radiation［R］.BEV, 2010.
［5］Allisy-Roberts P J, Boutillon M, et al.Comparisons of the standards for air kerma of the BEV and the BIPM for 137Cs and 60Coγrays［R］.BIPM, 1996.
［6］Allisy-Roberts P J, Boutillon M.Comparison of the standards for air kerma of the BNM-LPRA and the BIPM for 137Cs γ rays ［R］.BIPM, 1996.
［7］Allisy-Roberts P J, Kessler C, Toni M, et al.Comparison of the standards for air kerma of the ENEA-INMRI and the BIPM for 137Cs γ rays ［R］.BIPM,2010.
［8］Kessler C, Allisy-Roberts P J, Burns D.T.Comparison of the standards for air kerma of the ITN（Portugal）BIPM for 137Cs γ rays［R］.BIPM,2008.
［9］Kessler C, Roger P, Allisy-Roberts P J.Chul-Young Yi, Comparison of the standards for air kerma of the KRISS and the BIPM for 137Cs gamma radiation［R］.BIPM,2010.
［10］Allisy-Roberts P J, Kessler C,Burns D T.Comparison of the standards for air kerma of the LNE-LNHB and the BIPM for 137Cs gamma radiation［R］.BIPM,2008.
［11］Kessler C, Allisy-Roberts P J, Csete I,et al.Comparison of the standards for air kerma of the MKEH and the BIPM for 137Cs gamma radiation［R］.MKEH ,2010.
［12］Allisy-Roberts P J, Burns D T, Takate N, et al.Comparison of the standards for air kerma of the NMIJ and the BIPM for 137Cs γ rays ［R］.BIPM,2004.
［13］Perroche A M, Boutillon M.Comparison of the standards for air kerma of the NMIJ and the BIPM for 137Cs γ rays and 60Co γ rays［R］ .BIPM,1994.
［14］Allisy P J, Burns D T, Buerman L, et al.Comparison of the standards for air kerma of the PTB and the BIPM for 137Cs and 60Co gamma radiation［R］.BIPM,2005.
［15］Allisy P J, Boutillon M, Villevalde N D, et al.Comparison of the standards for air kerma of the VNIIM and the BIPM for 137Cs γ rays and 60Co γ rays［R］.BIPM,1998.
［16］Leitner A, Witzani J, Boutillon M, et al.International comparisons of air kerma standards in 137Cs gamma radiation［J］.Metrologia,1997,34(2):169-175.
［17］Bielajew A F.On the technique of extrapolation to obtain wall correction factors for ion chambers irradiated by photon beams［J］.Med Phys, 1990, 17:583-587.
［18］International Commission on Radiation Units and Measurements.Stopping powers for electrons and positrons［R］.ICRU Report37, Bethesda, MD, 1984
［19］Hubbell J H.Photon mass attenuation and energy absorption coef?cients from 1 keV to 20 MeV ［J］.Intl J Appl Radiat Isot, 1982, 33: 1269-1290.
［20］Rogers D W O, Bielajew A F.Wall attenuation and scatter corrections for ion chambers: measurements versus calculations［J］.Phys Med Biol, 1990, 35:1065-1078.
［21］Loftus T P.Standardization of Cesium-137 gamma-ray sources in terms of exposure units (Roentgens) ［J］.J Res Natl Bur Stand Sect A: Phys Chem, 1970, 74A:1-6.
［22］Perroche A M, Boutillon M.Determination of air kerma for 137Cs gamma rays［R］.BIPM, 1995.
［23］Attix F H.Introduction to radiological physics and radiation dosimetry［J］.Introduction to Radiological Physics and Radiation Dosimetry, 2007: 264-291.
［24］Hubbell J H.Photon cross sections, attenuation coef?cients, and energy absorption coef?cients from 10 keV to 100 GeV ［R］.NSRDS-NBS 29, Washington DC, National Bureau of Standards, US Government Printing Of?ce,1969.
［25］Boutillon M.Fonction de dissipation de l’énergie des électrons dans le carbone［R］.BIPM ,1968.
［26］Roesch W C.Dose for nonelectronic equilibrium conditions［J］.Rad Res, 1958, 9(4): 399-410.
［27］Boutillon M, Niatel M T.A study of graphite cavity chamber for absolute exposure measurements of 60Co gamma rays［J］.Metrologia, 1973, 9, 139-146.
［28］Engelke B A, Oetzmann W, Stuppek G.Die Messeinrichtungen der PTB［R］.PTB Bericht, Braunschweig, PTB-Dos-16, 1988.
［29］Correction d’humidité［R］.BIPM 1977.
2011, Vol. 32 
