Ionizing Radiation Measurements Rate our Services Technical Contacts:
Stephen M. Seltzer
Tel: 301/975-5552
E-mail: stephen.seltzer@nist.gov Marc F. Desrosiers
Tel: 301/975-5639
E-mail: marc.desrosiers@nist.gov James M. Puhl
Tel: 301/975-5581
E-mail: james.puhl@nist.gov Please contact the technical staff before shipping instruments or standards to the address listed below. Mailing Address:
National Institute of Standards and Technology
Attn: J. Puhl
100 Bureau Drive, Stop 8460
Gaithersburg, MD 20899-8460
Fax: 301/869-7682 Service ID
Number | Description of Services | Fee ($) | | Dosimetry of High-Energy Electron Beams | | 48010M | Dose Interpretation of NIST-Packaged Dosimeters Irradiated by Customer-Two Dosimeters | 1053 | | 48011M | Each Additional Dosimeter | 560 | | 48020S | Special Tests of Electron-Beam Dosimeters | At Cost | | Dosimetry of Photon Beams | | 49010C | Calibration Irradiations of Customer Supplied Dosimeters with 60Co Gamma-Rays | 471 | | 49020C | Dose Interpretation of NIST Transfer Dosimeters Irradiated by Customer, Three Dosimeters Plus Control(s) | 1456 | | 49030C | Dose Interpretation of Each NIST Transfer Dosimeter Package in Addition to Those Supplied Under 49020C | 359 | | 49050S | Special Measurement Services for Dosimeter Response and Dose Distributions | At Cost | Fees are subject to change without notice. back to top of page | back to index of ionizing radiation measurements Dosimeters are provided twice a year to users requesting assistance with absorbed-dose measurements in high-energy electron beams. The dosimeters are alanine dosimeters. The user irradiates the two furnished dosimeters to between 50 Gy and 80 Gy (5000 rad and 8000 rad) to water at electron energies between 5 MeV and 50 MeV, employing the irradiation geometry (field size, phantom, position of dosimeter in phantom) given in the "Protocol for Dosimetry of High-Energy Electrons," Physics in Medicine and Biology 11, 505 (1966). After irradiation, the dosimeters are returned to NIST for evaluation terms of absorbed dose in the phantom, using appropriate methods. These dose interpretations ignore certain corrections for the effects of spectral perturbations, and so represent a measurement quality assurance service rather than a calibration service. Measurements with Fricke dosimeters have a relative expanded uncertainty of 3.2%. The measurement procedure with alanine dosimeters is undergoing refinement; for the current procedure, the corresponding estimate of the relative expanded uncertainty is 2.3%. back to top of page | back to index of ionizing radiation measurements The following dosimetry services are for individual users of intense radiation fields, in particular large gamma-ray sources and electron accelerators up to approximately 10 MeV. These services include the administering of known absorbed doses of photons to customer-supplied dosimeters; supplying calibrated transfer standard dosimeters to customers for irradiation and subsequent NIST readout and dose interpretation; and special measurement services such as the administration of absorbed doses to a customer-defined, non-standard irradiation geometry. back to top of page | back to index of ionizing radiation measurements Calibration irradiations are available for customer-supplied dosimeters (such as solid radiochromic or liquid chemical types) or test samples that are sent to NIST, where they are packaged appropriately to provide electron-equilibrium conditions. The dosimeters and samples are irradiated in the NIST standard 60Co calibration facility to specific agreed-upon absorbed dose values in the nominal range of 10 Gy to 106 Gy. The dosimeters are then sent back to the customer for analysis and evaluation. Dosimeters must fit within a cylindrical volume 5 mm in height and 12 mm diameter. For our standard calibrated geometries (radiochromic film, alanine pellets, 2 mL ampoules, and red perspex), the absorbed dose (water) delivered to the dosimeter has a relative expanded uncertainty of 1.7%. back to top of page | back to index of ionizing radiation measurements NIST provides transfer standards in the form of sets of calibrated alanine dosimeters packaged in polystyrene. The sealed, packaged dosimeters are sent to the customer for irradiation to nominal agreed-upon absorbed dose levels in a prescribed geometrical arrangement. The unopened packaged dosimeters are then returned to NIST to be read and evaluated and the results are reported thus providing calibration of the customer's irradiator. The absorbed dose range suitable for use with the transfer dosimeters is 20 Gy to 200 kGy (2 krad to 20 Mrad) in water, silicon, aluminum, graphite, or certain plastics. The transfer standard calibrations (absorbed dose in water) have a relative expanded uncertainty of 1.3% for alanine dosimeters. back to top of page | back to index of ionizing radiation measurements Tests of dosimeter response, such as temperature dependence, dose rate dependence, and dose distributions in specific irradiation geometries, can be provided as special measurement services. These dose distribution measurements can include dose profiles in heterogenous absorbers and at interfaces of different materials. back to top of page | back to index of ionizing radiation measurements
References-Dosimetry of High-Energy Electron Beams NBS Measurement Services: Fricke Dosimetry in High-Energy Electron Beams , C. G. Soares, E. L. Bright, and M. Ehrlich, Natl. Bur. Stand. (U.S.), Spec. Publ. 250-4 (1987). Radiation Dosimetry: Electron Beams with Energies between 1 and 50 MeV , Report 35, International Commission on Radiation Units and Measurements, Bethesda, MD (1984). Uniformity of High-Energy Electron-Beam Calibrations , M. Ehrlich and P. J. Lamperti, Phys. Med. Biol. 14, 305 (1969). Proposed National Bureau of Standards Program for the Calibration of Instruments Used in High-Energy Electron and X-Ray Beams , M. Ehrlich, Ann. N.Y. Acad. Sci. 161, 139 (1969). back to top of page | back to index of ionizing radiation measurements
References-High-Dose Dosimetry Dosimetry Systems for Radiation Processing , W. L. McLaughlin and M. F. Desrosiers, Radiat. Phys. Chem. 46, 1163 (1995). ESR-Based Analysis in Radiation Processing , W. L. McLaughlin, M. F. Desrosiers and M. C. Saylor, Sterilization of Medical Products, Vol. VI (R. F. Morrissey, Ed.), Polyscience Publications, Inc. Marin Heights, Canada, p. 213 (1993). ESR Dosimetry , W. L. McLaughlin, Radial. Prot. Dosim. 47, 255 (1993). NBS Measurement Services: Dosimetry for High-Dose Applications , J. C. Humphreys, D. Hocken, and W. L. McLaughlin, Natl. Bur. Stand. (U.S.) Spec. Publ. 250-11 (Mar. 1988). Dosimetry for Industrial Radiation Processing, W. L. McLaughlin, J. C. Humphreys, and A. Miller, Natl. Bur. Stand. (U.S.) Spec. Publ. 609 (1982). A National Standardization Programme for High-Dose Measurements, W. L. McLaughlin, Technical Report No. 205, Intl. Atomic Energy Agency, Vienna, p. 17 (1981). Dye Film Dosimetry for Radiation Processing , J. C. Humphreys and W. L. McLaughlin, IEEE Trans. Nucl. Sci. NS-28 (2), 1797 (1981). The Measurement of Absorbed Dose and Dose Gradients , W. L. McLaughlin, Radial. Phy. Chem. 15, 9 (1980). Dosimetry Standards for Industrial Radiation Processing, W. L. McLaughlin, National and International Standardization of Radiation Dosimetry, Intl. Atomic Energy Agency, Vienna, p. 1 (1978). back to top of page | back to index of ionizing radiation measurements Date created: 06/30/1999
Last updated: 04/09/2009 | 