Enhancing electronic measuring systems for measuring very small ionization chamber currents

Highly sensitive charge measurement, which is suitable for currents down to several femtoamperes, is an important component of this electronic measuring system and is based on widely used charge measurement technologies [1, 2] of Department 6.3 (Radiation Protection Dosimetry). The setup is fully compatible with the modules of the previous electronic measuring system. Communication, both via various wire‑connected and wireless interfaces, is also possible. Moreover, the integration of further components required for the ionization chamber measurements such as ambient pressure, temperature and hygrometry, as well as high‑voltage generation for the chamber makes the use of other instruments superfluous. The logic unit is based on a Raspberry Pi Linux system on which the firmware has been implemented in a modular layer architecture. This layer architecture allows the independent and flexible use of individual components or functionalities, so that they can be used arbitrarily in various external applications, for example, via an ethernet interface. In addition, this architecture enables the integration of other logic components – such as a complete measurement sequence – into the firmware in order to obtain an independent digitalized measuring system.

Figure 1: Electronic measuring system for highly sensitive charge measurement with a connected ionization chamber and sensors for temperature and air humidity.

References

[1]        Buchholz, Gerd. Ladungsmesser. Physikalisch-Technische Bundesanstalt (PTB), Presse- und Öffentlichkeitsarbeit (Press and Information Office), 2004.

[2]        Buchholz, Gerd, and Wilfried Scheller. Bipolare programmierbare Hochspannungsquelle für Ionisationskammermessungen. Physikalisch-Technische Bundesanstalt (PTB), Presse- und Öffentlichkeitsarbeit (Press and Information Office), 2006.

Contact

B. Reinelt, Department 6.3, Working Group 6.35

P. Kramer, Department 6.3, Working Group 6.35