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Electronic personal dosemeter for neutrons

Direct-reading electronic personal dosemeters as available on the market in 2000, showed an unsatisfactory dependence of the dose equivalent reading on the energy of the incident neutron radiation. Investigations at the PTB have shown that the energy dependence of the neutron response can be improved. For this purpose, a silicon semiconductor detector with special converters and absorbers for neutron detection and linear combination of the pulse height signals of this detector is sufficient. It is also possible to determine the dose equivalent for photons by using the same detector and lower pulse height signals. This offers the possibility of building a moderately priced direct-reading personal dosemeter for mixed neutron/photon fields. The principal ideas are protected by patents. A battery-operated prototype with low-power microelectronics has been set up and an industry transfer (Mirion, DMC 2000 GN) has been achieved.

A neutron dosemeter with even more flat response for high-energy neutrons (0.1 MeV to 100 MeV) was obtained by reducing the effective depleted layer of the silicon detector of the above prototype dosemeter to 6 µm. The dose equivalent response of the dosemeter with the thin detector has been measured and calculated. Main ideas influenced the development of a direct reading dosemeter for astronauts at the ISS.

PTB prototype dosemeter DOS-2002 (Fig. 1) and commercial version DMC 2000 GN (Fig. 2)

Further information

References

  • Luszik-Bhadra, M.; Beck, P.; Berger, T.; Jaksic, A.; Latocha, M.; Rollet, S.; Vuotila, M.; Zechner, A.; Reitz, G.:
    Response Calculations for Silicon-based Direct-reading Dosemeters for Use at the International Space Station (ISS)
    Radiat. Meas. 45 (2010) 1548-1552

Patents

  • Luszik-Bhadra, M.; Wendt, W.:
    Method and device for determining a personxs dose in mixed neutron/photon fields
    EP 1 405 101 B1
  • Luszik-Bhadra, M.; Wendt, W.:
    Verfahren zur Bestimmung der Personendosis in gemischten Neutronen-/Photonen-Feldern sowie anderer Messgrößen in anderen Strahlenfeldern
    DE 101 32 550 B4
  • Luszik-Bhadra, M.; Wendt, W.:
    Method and device for determining the personal dose in mixed neutron/photon fields
    US 7,208,743 B2