Characterization of the JUDIDT Readout Electronics for Neutron Detection

Abstract

The Group for the development of neutron and gamma detectors in the Central Institute of Engineering, Electronics and Analytics (ZEA-2) at Forschungszentrum Jülich (FZJ) has developed, in collaboration with European institutes, an Anger Camera prototype for improving the impact point reconstruction of neutron tracks. The detector is a chamber filled with 3 He+CF4 gas for neutron capture and subsequent production of a tritium and a proton. The energy deposition by the ions gives rise to drifting electrons with an avalanche amplification as they approach a micro-strip anode structure. The scintillating light, generated during the electron drift and avalanche stage, is collected by four vacuum photomultipliers. The position reconstruction is performed via software algorithms. The JUDIDT readout electronics was modified at ZEA-2 to cope with the data acquisition requirements of the prototype. The results of the commissioning of the electronics are here presented and commented.

Software Tools for the Analysis of the Photocathode Response of Photomultiplier Vacuum Tubes

“…These programs performs a deeper investigation of the PMT data quantifying the level of homogeneity response, with and without the application of a lower level cut and of the pedestal subtraction (when the pedestal has been measured). In addition, in case of multi-anode PMTs the gain mismatch of the individual channels can be investigated, allowing to bring the non-homogeneity within few percents, This code was already used to investigate the relative gain of several Hamamatsu vacuum photomultipliers R580 during the commissioning of the JUDIDT electronics for an Anger Camera prototype [4].…”

Preliminary Investigation of a Waveform Analysis with the WASA and the ACQIRIS Readout Electronics

“…Different intensities of the LED were used leaving the voltage pulse width unchanged, to avoid an increase of the rise-time of the current signal generated by the PMT, whose high- voltage was left to its nominal value 1000 V. Instead, to change the intensity of the LED light output the voltage amplitude of the pulse generator was changed. The pre-amplifier built for the Anger camera project [5] was used here, soon after the PMT, after modifying the RC stage to the following configuration R = 1.5 kΩ , C = 33 pF + 68 pF.…”

“…To investigate the linearity of the system with the frequency filtering stage active a scan is performed, injecting into the WASA system waveforms with different amplitude values for the input voltage pulse, as shown in Tab. 5.…”