| Zugriffsnummer | 27799 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Time resolved X-ray spectroscopy |
| Autor(in); Institution |
Sievers, Peter; 6.3, Strahlenschutzdosimetrie, PTB-Braunschweig
Klammer, Jana; 6.3, Strahlenschutzdosimetrie, PTB-Braunschweig
Roth, Jürgen; 6.3, Strahlenschutzdosimetrie, PTB-Braunschweig
Michel, Thilo; University of Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics (ECAP), Erlangen, GERMANY
Anton, Gisela; University of Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics (ECAP), Erlangen, GERMANY
|
| Quelle/Jahr | 14th International Workshop on Radiation Imaging Detectors: Book of abstracts:(2012), 103 - 103 |
| Availability | [Online] |
| Herausgeber(in) |
Freitas, Elisabete Dinora Caldas de
|
| ISBN | 978-989-97922-1-0 |
| URL | |
| Konferenzangaben | International Workshop on Radiation Imaging Detectors (IWORID), Figueira da Fosz, Coimbra, 01-05, July, 2012, Portugal |
| Zusammenfassung | The investigation of the spectral change during a radiation pulse is of high interest in the field of radiation protection dosimetry. The aim of the work presented is to prove that the emitted spectrum of a novel X-ray generator, developed as reference equipment for pulsed photon radiation, has no time dependency during the pulse. Nowadays X-ray generators are pulsed by switching on and off the HV-generator. Therefore they have a relatively long rising edge until the pre-set acceleration voltage is reached. In contrary, our newly developed X-ray tube reduces the rise and fall time by up to a factor of 60. This was achieved by designing the X-ray tube as a triode and switching this tube on and off while the high voltage is constantly on. Thus only the quite low voltage of the additional grid has to be switched. For the measurements we used a Timepix detector [1] operated in Time of Arrival (ToA) mode. Secondary, the adjustable analogue threshold was swept through. With such a measurement over multiple X-ray pulses we obtained information about the timing and the energy distribution during the rise time of the HV-generator. The real impinging spectrum was gained by the deconvolution of the time resolved measured threshold scan. Such a deconvolution is necessary due to the blurring of the energy information in the pixelated sensor by effects like e.g. charge sharing or Compton scattering. For the deconvolution [2] itself the Bayesian approach was chosen as it turned out to be very stable even for low statistics in the measurements. With this setup of tube, detector and analysis it is possible to measure the spectral change in time. Figure 1 shows this for instance for generator pulsing. For the novel tube it is now possible to validate that the full voltage is reached quite instantaneous and therefore no spectral change can be observed. References [1] X. Llopart et al., Timepix, a 65k programmable pixel readout chip for arrival time, energy and/or photon counting measurements, Nucl. Instrum. Meth. A 581 (2007) 485. [2] P. Sievers et al., Bayesian deconvolution as a method for the spectroscopy of X-rays with highly pixelated photon counting detectors, 2012 JINST 7 P03003. |
