Digital Signal Processing for Particle Detectors in Front-End Electronics (original) (raw)

A Digital Signal Processing Module for Ge Semiconductor Detectors

IEEE Transactions on Nuclear Science, 2011

We have developed a digital signal processing module (APV7109) for a germanium semiconductor detector. The benchmark test of this module has shown good energy resolution and high throughput compared with conventional analog modules. By adding an extension module, the APV7109 can perform more advanced on-line calculations using the pulse shapes delivered by the on-board programmable logic. Therefore, user defined algorithms for pulse shape analysis can be used to adapt this module to various applications. Tests have demonstrated the feasibility of this extensible design.

Super-Altro 16: A Front-End System on Chip for DSP Based Readout of Gaseous Detectors

IEEE Transactions on Nuclear Science, 2013

This paper presents the architecture, design and test results of an ASIC specifically designed for the readout of gaseous detectors. The primary application is the readout of the Linear Collider Time Projection Chamber. The small area available (4mm 2 /channel) requires an innovative design, where sensitive analog components and massive digital functionalities are integrated on the same chip. Moreover, shut down (power pulsing) features are necessary in order to reduce the power consumption. The Super-Altro is a 16-channel demonstrator ASIC involving analog and digital signal processing. Each channel contains a low noise Pre-Amplifier and Shaping Amplifier (PASA), a pipeline ADC, and a Digital Signal Processor (DSP). The PASA is programmable in terms of gain and shaping time and can operate with both positive and negative polarities of input charge. The 10-bit ADC samples the output of the PASA at a frequency up to 40MHz before providing the digitized signal to the DSP which performs baseline subtraction, signal conditioning, drift correction and zero suppression. The chip has been fabricated in a 130 nm CMOS technology. Test measurements show correct functionality of the full system, and demonstrate that, using appropriate design techniques, the extensive digital circuitries produce little or no degradation of analog performance (particularly noise).

The DAQ and clock distribution system of CMS MIP Timing Detector

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

The Compact Muon Solenoid (CMS) detector at the CERN Large Hadron Collider (LHC) is undergoing an extensive Phase-II upgrade program to cope with the challenging conditions of the High-Luminosity LHC (HL-LHC). A new timing detector is designed to measure minimum ionizing particles (MIPs) with a time resolution of 30-60 ps during the entire HL-LHC phase. A common data acquisition (DAQ) system will collect data from readout chips, reconstruct timing information, and send data to the event builder. The MIP timing detector (MTD) DAQ system is built around the state-of-the-art ATCA-form-factor Serenity board with two high-speed FPGAs. The precision clock is synchronized to the LHC collision rate of 40 MHz and is received at the subsystem and transmitted to the detector via high-speed data links. The detector system with a full-readout chain has been tested using prototypes of the DAQ, on-detector electronics, and sensors, showing that the system can successfully achieve timing resolution below 30 ps.

Energy resolution and throughput of a new real time digital pulse processing system for x-ray and gamma ray semiconductor detectors

Journal of Instrumentation, 2013

New generation spectroscopy systems have advanced towards digital pulse processing (DPP) approaches. DPP systems, based on direct digitizing and processing of detector signals, have recently been favoured over analog pulse processing electronics, ensuring higher flexibility, stability, lower dead time, higher throughput and better spectroscopic performance. In this work, we present the performance of a new real time DPP system for X-ray and gamma ray semiconductor detectors. The system is based on a commercial digitizer equipped with a custom DPP firmware, developed by our group, for on-line pulse shape and height analysis. X-ray and gamma ray spectra measurements with cadmium telluride (CdTe) and germanium (Ge) detectors, coupled to resistivefeedback preamplifiers, highlight the excellent performance of the system both at low and high rate environments (up to 800 kcps). A comparison with a conventional analog electronics showed the better high-rate capabilities of the digital approach, in terms of energy resolution and throughput. These results make the proposed DPP system a very attractive tool for both laboratory research and for the development of advanced detection systems for high-rate-resolution spectroscopic imaging, recently proposed in diagnostic medicine, industrial imaging and security screening.

A Data Processing System for Real-Time Pulse Processing and Timing Enhancement for Nuclear Particle Detection Systems

IEEE Transactions on Nuclear Science, 2013

This paper presents a digital data processing system that allows real-time processing of neutron and gamma-ray pulses. The captured data are processed in real time on a field programmable gate array device. A number of pulse processing algorithms are implemented on this system including correlation-based triggering and on-the-fly pulse shape discrimination. Moreover, a timing enhancement technique using correlations is presented that allows sub-sample timing accuracy of the time-of-arrival of pulses. Finally, simulation and measurement results are presented and discussed in detail to show the system's potential.

A DSP equipped digitizer for online analysis of nuclear detector signals

2007

In the framework of the NUCL-EX collaboration, a DSP equipped fast digitizer has been implemented and it has now reached the production stage. Each sampling channel is implemented on a separate daughter-board to be plugged on a VME mother-board. Each channel features a 12-bit, 125 MSamples/s ADC and a Digital Signal Processor (DSP) for online analysis of detector signals. A few algorithms have been written and successfully tested on detectors of different types (scintillators, solid-state, gas-filled), implementing pulse shape discrimination, constant fraction timing, semi-Gaussian shaping, gated integration. r

Evaluation of digital pulse processing techniques for a β-γ coincidence counting system

Applied Radiation and Isotopes, 2020

Signal processing is a core part of any electronic chain for radioactivity measurement systems and can influence measurement results drastically. A thorough study of the different alternatives for this treatment is especially worthwhile when developing a new digital system. This article describes an evaluation performed to optimize the digital pulse processing stage of the β-γ coincidence counting system at the Institute of Radiation Physics (IRA) designated laboratory for the activity unit. This study is a part of IRA's digitalization project to modernize the aging analog electronic hardware of its primary measurement systems. The β-γ coincidence counting system consists of a plastic scintillation detector in the beta channel and a welltype NaI detector in the gamma channel. Six pulse shaping digital filters along with amplitude calculation algorithms were implemented to obtain beta and gamma pulse amplitude values. In addition, four timing digital filters and time pick-off methods were set up to calculate arrival times (timestamps) for the pulses generated by both detectors. Filter parameters and algorithm settings were adjusted to obtain the best performance. Combination of filters into traditional two channel (fast for timing and slow for shaping) or one channel configuration using dCFD (digital constant fraction discrimination) and LE (leading edge) time pick-off methods were also tested and compared to study the whole digital pulse processing system, using both real measurement signals (241 Am, 137 Cs, 60 Co and 166m Ho) and simulated reference pulses. The results of these tests were quantified by evaluating the following metrics: processing speed, signal-to-noise ratio (SNR) at different energies, gamma energy resolution, time measurement accuracy, time resolution and detection efficiency. The results of this evaluation provide a rational ground to assess the system and help decide which digital pulse processing (DPP) method should be the most appropriate.