D. Przyborowski

Forward instrumentation for ILC detectors

Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10?3 and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised.

A general purpose multichannel readout system for radiation detectors

The design and performance of a multichannel readout system for radiation detectors are presented. The developed 32-channel prototype system comprises fast, low-noise, front-end followed by a 10-bit multichannel digitizer and on-board FPGA data concentrator, processing the stream of digitized data with up to 6.4 Gbps rate. The operation of the whole system is managed by a microcontroller. The system can work in self-triggering mode or can be triggered externally. The implemented trigger mechanism allows for elaborate event filtering and selection of data to be transmitted to the host through the USB interface. A wide spectrum of measurements showing and quantifying the key system parameters like data transmission rate and event rate, noise, and gain are presented to prove the correct system performance. To increase the power efficiency in experiments with a non-continuous beam structure, a power pulsing mechanism is implemented and verified experimentally.

A 10-Bit Multichannel Digitizer ASIC for Detectors in Particle Physics Experiments

The design and measurement results of a multi-channel power scalable 10-bit digitizer ASIC developed for the luminosity detector at the future linear colliders (ILC/CLIC) are discussed. The 8 channel prototype with different modes of output data serialization was designed and fabricated in a 0.35 μm CMOS technology. The ASIC works for sampling rates from about 10 kS/s to 25 MS/s (50 MS/s in single channel mode) allowing linear scaling of ADCs and serializer power consumption (0.8 mW/MS/s ADC core, 1.2 mW/MS/s total per channel). A wide spectrum of static and dynamic measurements confirm very good ADC resolution (ENOB = 9.7 bits), excellent channel uniformity and negligible crosstalk. To profit from non-continuous detector operation in linear collider experiments and to save power consumption, fast periodic power pulsing is implemented.

A 10-bit Low-Power Small-Area High-Swing CMOS DAC

The design and measurements of a prototype general purpose digital to analog converter for readout systems in high energy physics experiments are presented. The main goals for the proposed DAC are low power consumption, small die area and high-swing voltage output. The 10-bit DAC design is based on a current steering architecture which includes a high-swing class AB output amplifier. The prototype ASIC is fabricated using 2P-4M 0.35- ¿m technology. Measurements of maximum differential (DNL) and integral (INL) nonlinearity both show 0.42 LSB. The total power consumption is below 0.6 mW while the core area is 0.18 mm2.

Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e- collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

Architecture of the upgraded BCM1F backend electronics for Beam Conditions and Luminosity measurement

The Beam Radiation Instrumentation and Luminosity Project of the CMS experiment consists of several beam monitoring systems and luminometers. The upgraded Fast Beam Conditions Monitor is based on 24 single crystal diamond sensors with a two-pad metallization and a custom designed readout. Signals for real time monitoring are transmitted to the counting room, where they are received and processed by new back-end electronics designed to measure count rates on LHC collision, beam induced background and activation products to be used to determine the luminosity and the machine induced background. The system architecture and the signal processing algorithms will be presented.

Design and Performance of the BCM1F Front End ASIC for the Beam Condition Monitoring System at the CMS Experiment

We present the design and the test results of the BCM1F front end ASIC designed for readout of diamond sensors used in the Beam Condition Monitoring system at the Compact Muon Solenoid (CMS) experiment built in the European Organization for Nuclear Research (CERN) in Geneva. The design comprises a fast transimpedance preamplifier with active feedback, a shaper stage and high-performance differential output buffer. The front end amplifier shows good linearity for input charges below 7 fC, signal gain of about 50 mV/fC, equivalent noise charge (ENC) around 400 e- for 2 pF and less than 700 e- for 5 pF input capacitance. The measured peaking time (Tp) is in the range from 6.6 to 9.4 ns depending on the applied bias conditions and the input capacitance. The full-width-at-half-maximum (FWHM) of the response is kept below 10 ns, which allows for efficient beam halo detection. The return time after the detector signal overdrive is maintained below 25 ns. These two latter parameters make the presented circuit compatible with high data rate applications.

Design of the forward straw tube tracker for the PANDA experiment

The design of the Forward Tracker for the Forward Spectrometer of the PANDA experiment is described. The tracker consists of 6 tracking stations, each comprising 4 planar double layers of straw tube detectors, and has a total material budget of only 2% X0. The straws are made self-supporting by a 1 bar over-pressure of the working gas mixture (Ar/CO2). This allows to use lightweight and compact rectangular support frames for the double layers and to split the frames into pairs of C-shaped half-frames for an easier installation on the beam line.

Development of radiation-hard bandgap reference and temperature sensor in CMOS 130 nm technology

A stable reference voltage (or current) source is a standard component of todays microelectronics systems. In particle physics experiments such reference is needed in spite of harsh ionizing radiation conditions, i.e. doses exceeding 100 Mrads and fluences above 1e15 n/cm2. After such radiation load a bandgap reference using standard p-n junction of bipolar transistor does not work properly. Instead of using standard p-n junctions, two enclosed layout transistor (ELTMOS) structures are used to create radiation-hard diodes: the ELT bulk diode and the diode obtained using the ELTMOS as dynamic threshold transistor (DTMOS). In this paper we have described several sub-1V references based on ELTMOS bulk diode and DTMOS based diode, using CMOS 130 nm process. Voltage references the structures with additional PTAT (Proportional To Absolute Temperature) output for temperature measurements were also designed. We present and compare post-layout simulations of the developed bandgap references and temperature sensors, which show correct operation (<;1mV bandgap stability, linear PTAT) in teperature range -20 to 100 celsius degree.

The fast beam condition monitor BCM1F backend electronics upgraded MicroTCA-based architecture

The Beam Radiation Instrumentation and Luminosity Project of the CMS experiment, consists of several beam monitoring systems. One system, the upgraded Fast Beams Condition Monitor, is based on 24 single crystal CVD diamonds with a double-pad sensor metallization and a custom designed readout. Signals for real-time monitoring are transmitted to the counting room, where they are received and processed by new back-end electronics designed to extract information on LHC collision, beam induced background and activation products. The Slow Control Driver is designed for the front-end electronics configuration and control. The system architecture and the upgrade status will be presented.