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Results of research and development work

Secondary standard for the personal dose equivalent in 10 mm depth

Ionization chamber for the direct measurement of the personal dose equivalent, Hp(10), in the energy range between 12 keV and 1,4 MeV and in the angular range from 0° to 75°. Specially suited for the dosimetric calibration of X-ray facilities in the energy range below 100 kV accelerating voltage.

Literature:

  • Ankerhold, U., Behrens, R., Ambrosi, P.:
    A prototype ionisation chamber as a secondary standard for the measurement of personal dose equivalent, Hp(10), on a slab phantom
    Radiat. Prot. Dosim., Vol. 86, No. 3, pp. 167-173 (1999)

     

Contact:

Opens window for sending emailDr. Oliver Hupe(at)ptb.de
phone: +49 (0) 531-592-6310

Distribution: PTW-Freiburg

Costs for Calibration

http://www.ptw.de/ptw_htm/products/rp/ionc/main.htm#hp6

http://www.ptw.de/ptw_htm/products/rp/ionc/main.htm#hp6

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Beta secondary standard for radiation protection purposes (low dose rates), BSS2

BSS 2 beta secondary standard for carrying out irradiations using beta radiation of mean energies between 60 keV and 800 keV. The radiation qualities are in compliance with the series of standards ISO 6980.

The Opens external link in new windowmanual is available.

For the users of the BSS 2, the file "Initiates file downloadBetaFakt.ini" is available, this file contains several correction factors used by the software of the BSS 2.
Several letters containing Initiates file downloaduser information have been made available by PTB in the past. Some of them are not relevant any more. However, for the sake of completeness all are made available.

Literature:


Contacts:
dosimetric matters:
Dr. Rolf Behrens(at)ptb.de
phone: +49 (0) 531-592-6340

technical matters:
Opens window for sending emailDipl.-Ing. Jürgen Roth(at)ptb.de
phone: +49 (0) 531-592-6350

Distribution:
Opens external link in new windowEckert & Ziegler Nuclitec GmbH
Enrico.Raus(@)ezag.com
phone: +49 (0) 5307-932-235


The Calibration of the radiation sources is carried out at PTB in the department.

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Eye lens dosimetry

The International Commission on Radiological Protection (ICRP) has reduced their recommended dose limit for the eye lens from 150 mSv down to 20 mSv per year for occupational exposure (Opens external link in new windowwww.icp.org//page.asp?id=123). Detailed information is available in Opens external link in new windowICRP 118. This recommendation has been adopted in the European directive Opens external link in new window2013/59/EURATOM and consequently, in national law for all EU member states. Therefore, several investigations regarding eye lens dosimetry have been carried out. This part of the report focuses on PTB’s activities since then.

First it is advisable to think about the quantity to be used for the purpose under consideration:

In pure photon radiation fields, Hp(0.07) may be used. Then, extremity dosemeters are suitable when worn near the eye and in case they detect radiation scattered back from the head. After this, they can be calibrated on both the ISO water slab phantom and the ISO polymethyl methacrylate (PMMA) rod phantom:

  • R. Behrens, J. Engelhardt, M. Figel, O. Hupe, M. Jordan, and R. Seifert: Hp(0.07) photon dosemeters for eye lens dosimetry: Calibration on a rod vs. a slab phantom, Opens external link in new windowRad. Prot. Dosim. 148, 139 (2012)

In case beta radiation significantly contributes to the dose, Hp(3) is advisable:

  • R. Behrens: On the operational quantity Hp(3) for eye lens dosimetry, Opens external link in new windowJ. Radiol. Prot. 32 (2012), 455-464. In short: The slab phantom is for calibration at normal radiation incidence as appropriate as the cylinder phantom.

For Hp(3) dosemeters, both the slab and the cylinder phantoms are suitable for calibration (usually at 0°). However, type tests (especially above 30° radiation incidence) should be carried out on a cylinder phantom:

The following papers give conversion coefficients from air kerma to Hp(3) for the slab phantom and cylinder phantom; thus, enabling the performance of photon calibrations and irradiations in terms of Hp(3):

Photon area dosemeters can be irradiated or calibrated in terms of H′(3), as conversion coefficients from air kerma to H′(3) for the ICRU sphere are available for both mono-energetic photons as well as for radiation qualities according to ISO 4037:

Likewise, beta dosemeters can be irradiated or calibrated in terms of Hp(3) and H′(3), as the Beta Secondary Standard, BSS 2, has been extended:

Investigations in nuclear medicine yielded dose rate constants of beta-photon nuclides as well as the shielding effect of goggles for beta-photon nuclides:

  • B. Szermerski et al.: Dose rate constants for the quantity Hp(3) for frequently used radionuclides in nuclear medicine, Opens external link in new windowZ. Med. Phys. 26 (2016) 304
  • I. Bruchmann et al.: Impact of radiation protection means on the dose to the lens of the eye while handling radionuclides in nuclear medicine, Opens external link in new windowZ. Med. Phys. 26 (2016) 298

Conversion coefficients from fluence to the equivalent dose to the lens of the eye, Hlens, are given in the following papers:

At least two comparisons for eye lens dosemeters in terms of Hp(3) were conducted, a third one is currently being carried out:

Since ICRP recommended the reduced dose limit for the lens of the eye in 2011, and partly even before, international organizations started several actions. Among them are EURADOS as well as IAEA:

Furthermore, several international documents have already been adopted or are currently being revised to implement the operational quantities Hp(3) and H'(3):

  • IEC 61331-3: Requirements to medical protective equipment (2014)
  • ISO 4037: Photon reference radiation fields (2019)
  • ISO 6980: Beta reference radiation fields (2004 – currently in revision)
  • IAEA TecDoc 1731: Dosimetry in practice (2013)
  • ISO 15382: Dosimetry in practice (2015)
  • IEC 62387: Requirements to dosemeters (passive) (2020)
  • IEC 61526: Requirements to dosemeters (active) (2010 – currently in revision)
  • ISO 14146: Routine test for dosemeters (2018)

List of publications

Contact

Opens window for sending emailDr. Rolf Behrens (rolf.behrens(at)ptb.de)
phone: +49 (0) 531-592-6340

X-ray spectrometry

Determination of the spectral photon flux of X-radiation fields with the aid of a high-purity germanium semiconductor detector.
The measured Initiates file downloadspectra are available in ASCII format.

Literature:

  • ANKERHOLD, U., BEHRENS, R., AMBROSI, P.:
    X-ray spectrometry of low energy photons for determining conversion coefficients from air kerma, Ka, to personal dose equivalent, Hp(10), for radiation qualities of the ISO narrow spectrum series
    Radiat. Prot. Dosim., Vol. 81, No. 4, pp 247-258 (1999)

  • ANKERHOLD, U.:
    Catalogue of X-ray spectra and their characteristic data -ISO and DIN radiation qualities, therapy and diagnostic radiation qualities, unfiltered X-ray spectra-
    PTB report: Opens external link in new windowPTB-Dos-34 (2000), ISBN: 3-89701-513-7

Contact:

Opens window for sending emailDr. Oliver Hupe(at)ptb.de
phone: +49 (0) 531-592-6200

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In-situ photon spectrometer

Instrument for measuring the energy and angular distribution of radiation fields at workplaces. Measuring ranges: 30 keV to 300 keV and three independent angular ranges in the front half-space.

Literature:

  • Alt, R., Ambrosi, P., Böhm, J., Hilgers, G., Jordan, M., Ritzenhoff, K.-H.:
    The generation of the response matrix of hemispherical CdTe detectors
    Nuclear Instruments and Methods in Physics Research A353 (1994) 71

  • Ambrosi, P., Hilgers, G.:
    Strahlungsfelder und Expositionbedingungen an Arbeitsplätzen
    Strahlenschutzpraxis 4/99 (1999) 53


Contacts:

Dr. Gerhard Hilgers(at)ptb.de
phone: +49 (0) 531-592-6620

Opens window for sending emailDr. Herbert Janßen(at)ptb.de
phone: +49 (0) 531-592-6010

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Gliding shadow film badges

Individual dosemeters suitable for the official monitoring of persons occupationally exposed to radiation. Measurement of both, the old and the new quantities applicable in radiation protection (depending on the evaluation method chosen).

Literature:

  • Ambrosi, P., Böhm, J., Hilgers, G., Jordan, M., Ritzenhoff, K.-H.:
    The gliding-shadow method and its application in the design of a new film badge for the measurement of the personal dose equivalent Hp(10)
    PTB-Mitteilungen 104 (1994) 334
  • Ritzenhoff, K.-H., Jordan, M., Hilgers, G., Böhm, J., Ambrosi, P.:
    A new film badge for the measurement of the personal dose equivalent Hp(10) using the gliding-shadow methodProceedings of the 9. International Congress on Radiation Protection, Wien 1996, Vol.4, 266

     

Contacts:

Dr. Oliver Hupe(at)ptb.de
phone: +49 (0) 531-592-6300

Dosimetry service in Dortmund

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TLD-based few-channel spectrometer

A TLD-based instrument for measuring the energy distribution in high-intensity electron and photon radiation fields (also pulsed radiation) in the energy range between 400 keV up to a maximum of 100 MeV (electrons) and between 20 keV and 2 MeV (photons).

version for photons up to 100 keV is available.

Literature:

Contact:

Dr. Rolf Behrens(at)ptb.de
phone: +49 (0) 531-592-6340

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TLD ambient dose equivalent area dosemeter

TLD-based dosemeter badge for the measurement of the ambient dose equivalent, H*(10). The dosemeter meets the requirements of the standard DIN 25 483 "Methods for environmental monitoring using integrating solid-state dosemeters" in the dose range from 50 µSv to 10 Sv, in the energy range from 24 keV to 3 MeV and for all angles of incidence.

Literature:

  • Ahlborn, M.:
    Das Thermolumineszenz (TL) Dosimetrie-System ALNOR DOSACUS
    Laboratory report PTB-6.51-98-1 (1998)

  • Behrens, R.; Ambrosi, P.:
    Anwendung eines Verfahrens zur Umgebungsüberwachung mit integrierenden Festkörperdosimetern
    PTB-Bericht: PTB-Dos-46 (2004), ISBN: 3-86509-101-6

Contact:

Dr. Rolf Behrens(at)ptb.de
phone: +49 (0) 531-592-6340

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Ladungsmesseinrichtung für Ionisationskammern

Die in allen Funktionen über einen Rechner steuerbare Ladungsmesseinrichung besteht neben einer Zeitsteuerung aus Integrator- und Hochspannungseinschüben. Es stehen 6 Ladungsbereiche von 20 pC bis 2 µC zur Verfügung (Eingangsruhestrom < 3 fA). Die Hochspannungseinschübe liefern Spannungen von 0 V bis ± 660 V.

Schriften:

  • Buchholz, G.:
    Ladungsmesser

    PTB-Bericht: PTB-EW-12 (2004), ISBN: 3-86509-158-x

Ansprechpartner:
Opens window for sending emailJürgen Roth(at)ptb.de
Tel.: 0531-592-6350 

Hochempfindlicher Ladungsmesser

Zur Messung von Strömen < 10 fA wurde für die oben beschriebene Ladungsmesseinrichtung ein Integrator mit einem Eingangsruhestrom < 0,5 fA entwickelt. Der Integrator ist in allen Funktionen über einen Rechner steuerbare. Es stehen 2 Ladungsbereiche von 20 pC und 200 pC zur Verfügung.

Schriften:

  • Buchholz, G.:
    Hochempfindlicher Ladungsmesser

    PTB-Bericht: PTB-EW-15 (2013), ISBN: 978-3-95606-048-9

Ansprechpartner:
Opens window for sending emailJürgen Roth(at)ptb.de
Tel.: 0531-592-6350

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