BiCMOS amplifier–discriminator integrated circuit for gas-filled detector readout

The paper presents a 16-channel amplifier-discriminator designed in BiCMOS technology. It will be used for the binary parallel readout of gas-filled detectors being designed at the European Synchrotron Radiation Facility. The circuit (named AMS211) has been manufactured. The measured transimpedance gain (400 KΩ), bandwidth (25 MHz) and noise (1570 e⁻+95 e⁻/pF ENC) well match the simulated results. The discriminator thresholds are individually controlled by built-in Digital to Analogue Converter. The experience gained with a first prototype of readout electronics indicates that the AMS211 should meet our requirements.     

Energy and spatial response of silicon strip detectors to X-rays

This paper describes an experimental investigation of the energy and spatial response of silicon strip detectors used for X-ray measurements. The measurements of single strip amplitude distributions have been performed for a p⁺–n silicon strip detector irradiated with X-rays for different detector bias voltages and for two measurements geometries (with the detector irradiated from either the strip side or from the ohmic contact side). The measured amplitude distributions have been compared with those obtained from simulations using the developed simulation package. The spatial response of the detector has been measured by scanning an edge across the strips and measuring the corresponding strip count rate. The measured spatial response has been compared with that obtained from simulations.     

Performance of a radiation hard 128 channel analogue front-end chip for the readout of a silicon-based hybrid photon detector

The performance is described of a front-end chip, the SCT128A-LC chip, originally developed for the readout of a silicon based Hybrid Photon Detector (HPD), which is part of an RICH detector to be run in an LHC experimental environment. The relatively low signal charge from single photoelectrons, impinging on the silicon pad sensor, put very stringent requirements on the noise performance of the front-end chip. An absolute noise calibration using X-ray sources and a ²⁴¹Am γ source was performed. It is demonstrated that sufficiently good signal over noise ratio can be obtained to use this chip for the read-out of an HPD in LHC experiments.     

Large area microchannel plate detector with amorphous silicon pixel array readout for fast neutron radiography

Fast neutron radiography is a non-destructive testing technique with a variety of industrial applications and the capability for element sensitive imaging for contraband and explosives detection.

Commonly used position sensitive detectors for fast neutron radiography are based on charge coupled devices (CCDs) and scintillators. The limited format of CCDs implies that complex optical systems involving lenses and mirrors are required to indirectly image areas that are larger than 8.6 cm×11.05 cm. The use of optics reduces the light collection efficiency of the imaging system, while the efficiency of hydrogen rich scintillators exploiting the proton recoil reaction is limited by the hydrogen concentration and the magnitude of the neutron scattering cross-section.

The light conversion step inevitably involves a tradeoff in scintillator thickness between light yield and spatial resolution.

The development of large area amorphous silicon (a-Si) panel flat panel photodiode arrays and direct neutron-to-charge converters based on microchannel plates, provide an attractive new form of high resolution, large area, fast neutron imaging detector for the non-destructive imaging of large structures. This paper describes some recent results of both Monte Carlo simulations and measurements for such a detector.     

CD: A double sided silicon strip detector for radioactive nuclear beam experiments

A very compact double sided silicon strip detector array is described, designed for use in reaction studies involving radioactive nuclear beams. It is small enough to fit inside a large solid angle γ-detector array and will enable Doppler-shift corrections at energies in the vicinity of the Coulomb barrier. The detector provides sufficient energy and time-of-flight resolution for the identification of light reaction products and can be set up to cover a substantial part of the scattering angular distribution with good resolution.

The device is available in thicknesses of up to 500 μm to stop all interesting reaction products. Moreover, a very thin (35–40 μm) variant of this detector is described that can be used as an energy loss detector in a ΔE−E telescope geometry followed by a detector that measures the residual energy. This provides additional particle identification capabilities, e.g. in light exotic nuclei induced reactions. First results from a commissioning run using a post-accelerated radioactive beam are presented.     

High precision axial coordinate readout for an axial 3-D PET detector module using a wave length shifter strip matrix

We describe a novel method to extract the axial coordinate from a matrix of long axially oriented crystals, which is based on wavelength shifting (WLS) plastic strips. The method allows building compact 3-D axial gamma detector modules for PET scanners with excellent 3-D spatial, timing and energy resolution while keeping the number of readout channels reasonably low. A voxel resolution of about 10 mm³ is expected. We assess the performance of the method in two independent ways, using classical PMTs and G-APDs to read out the LYSO (LSO) scintillation crystals and the WLS strips. We observe yields in excess of 35 photoelectrons from the strips for a 511 keV gamma and reconstruct the axial coordinate with a precision of about 2.5 mm (FWHM).