A complete four channel acquisition system for high-resolution spectroscopy has been designed and realized. The analog section is composed of four semi-Gaussian shaping amplifiers with two software-selectable shaping times. The shaping times (150 and 450 ns) were chosen to perform either high rate or best resolution XRF measurements with state-of-the-art multielement silicon drift detector. The pulses' amplitudes are caught by four large-bandwidth peak-stretchers whose outputs are multiplexed into a single 10 MHz 12-bit analog-to-digital converter (ADC). A field-programmable gate array (FPGA) operating at 24 MHz (or 48 MHz) clock frequency controls the whole process and stores the four spectra in the on-chip RAM, thus guaranteeing a maximum counting rate per bin of 332 kcps and an overall counting rate in excess of 4 Mcps. The system interfaces the host PC by means of the enhanced parallel port with a custom made control software for data visualization and analysis as in a conventional MCA system. If more than four channels have to be managed, various boards can be operated in parallel on the same EPP bus.
High-speed FPGA-based pulse-height analyzer for high resolution X-ray spectroscopy
2005
Abstract
A complete four channel acquisition system for high-resolution spectroscopy has been designed and realized. The analog section is composed of four semi-Gaussian shaping amplifiers with two software-selectable shaping times. The shaping times (150 and 450 ns) were chosen to perform either high rate or best resolution XRF measurements with state-of-the-art multielement silicon drift detector. The pulses' amplitudes are caught by four large-bandwidth peak-stretchers whose outputs are multiplexed into a single 10 MHz 12-bit analog-to-digital converter (ADC). A field-programmable gate array (FPGA) operating at 24 MHz (or 48 MHz) clock frequency controls the whole process and stores the four spectra in the on-chip RAM, thus guaranteeing a maximum counting rate per bin of 332 kcps and an overall counting rate in excess of 4 Mcps. The system interfaces the host PC by means of the enhanced parallel port with a custom made control software for data visualization and analysis as in a conventional MCA system. If more than four channels have to be managed, various boards can be operated in parallel on the same EPP bus.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
