H. Angerer

The PANDA GEM-based TPC prototype

Abstract We report on the development of a GEM-based TPC detector prototype for the PANDA experiment. The design and requirements of this device will be illustrated, with particular emphasis on the properties of the recently tested GEM-detector, the characterization of the read-out electronics and the development of the tracking software that allows to evaluate the GEM-TPC data.

SODA: Time distribution system for the PANDA experiment

The PANDA data acquisition system will operate in trigger-less mode and collect about 100 GBytes of data per second from more than a thousand front-end modules. The information from all detectors is combined into data blocks, every block corresponds to 500 microseconds of beam. The SODA (Synchronization Of Data Acquisition) project aims to develop a versatile optical network system which is, first of all, able to provide a common reference time with a precision better than 20 ps R.M.S. In addition, the system synchronizes data taking with the burst structure and performs monitoring of data acquisition modules. Furthermore, it takes responsibility for data flow control. The core of the system is a point-to-multipoint bidirectional optical link which is able to broadcast information from a master module to few hundred destinations and to acquire information from the destination modules via a passive optical fiber network. The first prototype system has been built and tested. The architecture of the SODA system, the hardware implementation and the performance parameters of the prototype system are discussed.

Fast photon detection for particle identification with COMPASS RICH-1

Particle identification at high rates is an important challenge for many current and future high-energy physics experiments. The upgrade of the COMPASS RICH-1 detector requires a new technique for Cherenkov photon detection at count rates of several

A new multiwire proportional chamber with fast single strip readout and individual analog to digital conversion

10^6

Pattern recognition and PID for COMPASS RICH-1

per channel in the central detector region, and a read-out system allowing for trigger rates of up to 100 kHz. To cope with these requirements, the photon detectors in the central region have been replaced with the detection system described in this paper. In the peripheral regions, the existing multi-wire proportional chambers with CsI photocathode are now read out via a new system employing APV pre-amplifiers and flash ADC chips. The new detection system consists of multi-anode photomultiplier tubes (MAPMT) and fast read-out electronics based on the MAD4 discriminator and the F1-TDC chip. The RICH-1 is in operation in its upgraded version for the 2006 CERN SPS run. We present the photon detection design, constructive aspects and the first Cherenkov light in the detector.

A position sensitive cathode strip detector with single strip readout

Abstract A new precision MWPC with an active length of 400 mm has been built for the Munich Q3D spectrograph. The readout method uses the individual amplitude signals of narrow cathode strips (3 mm width, 0.5 mm spacing). Each of these signals is converted into a digital word by an individual fast ADC. A newly developed hard wired logic calculates the position of the particle event by the center of gravity method with a dead time of about 108 μs. The position resolution in test measurements simulating particle events was better than 0.1 mm.

The universal sampling ADC readout system of the COMPASS experiment

Abstract A package for pattern recognition and PID by COMPASS RICH-1 has been developed and used for the analysis of COMPASS data collected in the years 2002–2004, and 2006–2007 with the upgraded RICH-1 photon detectors. It has allowed the full characterization of the detector in the starting version and in the upgraded one as well as the PID for physics results. We report about the package structure and algorithms, and the detector characterization and PID results.

The fast readout system for the MAPMTs of COMPASS RICH-1

Abstract The detector presented is a special kind of MWPC combined with a scintillator and is used for nuclear spectroscopy at the Munich Q3D magnetic spectrograph. It allows both identification and position determination of the incident particles. The position is derived from the charge distribution influenced on a few neighboring cathode strips which are read out individually. During data acquisition the position is calculated with the center of gravity method. This reduces the dead time per event to about 60 μs but causes a systematic error. This is eliminated later in a replay, which calculates the position by fitting the charge distribution. With this method the position precision is better than 0.1 mm.

First results of the PixelGEM central tracking system of COMPASS

The COMPASS experiment (COmpact Muon Proton Apparatus for Structure and Spectroscopy) is a fixed target experiment located at the CERN Super Proton Synchrotron. The physics program is focused on the study of hadron structure and hadron spectroscopy with high intensity muon and hadron beams, up to 160 GeV/c for muons and 190 GeV/c for hadrons respectively. To allow the tracking of charged particles with very low and as well very high momentum, COMPASS comprises two magnetic spectrometer stages extending to a total length of 60 m. From the data acquisition point of view, about 200000 analog detector channels have to be read along the complete experiment. Depending on the detector signal characteristics and the number of channels, this task is realized by frontend electronics using either dedicated ASICs and/or sampling analog-to-digital (ADC) or time-to-digital (TDC) components. The sampling ADC based readout system of the COMPASS experiment comprises today over 127k channels equipped with the APV25 frontend ASIC and 5728 direct sampling channels. An important feature from the beginning was the combination of data transfer, clock and trigger distribution and configuration access within a standardized serial interface between the different ADC modules and the first stage of data concentrator modules. By choosing between a copper or fiber realization for this interface, either a low cost interconnect or a link with galvanic decoupling can be realized. The ongoing development of the sampling ADC electronics is focused on the migration toward the Advanced Telecom Computing Architecture (ATCA) crate standard, to overcome the backplane bandwidth limitations in VME systems. In addition, the ATCA standard provides better cooling and monitoring capabilities. To simplify the transition to ATCA, the MSADC module was already realized as a mezzanine card, which can be mounted on an ATCA based carrier card as well. In addition, the MSADC card fits also to the MicroTCA form factor, which allows to provide a handy building block for laboratory based data acquisition systems.

Fast photon detection for the COMPASS RICH detector

A fast readout system for the upgrade of the COMPASS RICH detector has been developed and successfully used for data taking in 2006 and 2007. The new readout system for the multi-anode PMTs in the central part of the photon detector of the RICH is based on the high-sensitivity MAD4 preamplifier-discriminator and the dead-time free F1-TDC chip characterized by high-resolution. The readout electronics has been designed taking into account the high photon flux in the central part of the detector and the requirement to run at high trigger rates of up to 100 kHz with negligible dead-time. The system is designed as a very compact setup and is mounted directly behind the multi-anode photomultipliers. The data are digitized on the front-end boards and transferred via optical links to the readout system. The readout electronics system is described in detail together with its measured performances.