A new wire chamber front-end system, based on the ASD-8 B chip

The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in-total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier front-end board, housing two amplifier-shaper-discriminatorchips ASD-8 B. The main features of this board are a fast single-wire readout, a high integration density, a low power consumption and compatibility to common instrumentation standards;The board represents the first successfully running application of the ASD-8 for wire chamber readout. (C) 1999 Elsevier Science B.V. All rights reserved

A new wire chamber front-end system, based on the ASD-8 B chip.

The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in-total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier front-end board, housing two amplifier-shaper-discriminatorchips ASD-8 B. The main features of this board are a fast single-wire readout, a high integration density, a low power consumption and compatibility to common instrumentation standards;The board represents the first successfully running application of the ASD-8 for wire chamber readout. (C) 1999 Elsevier Science B.V. All rights reserved

Measurement and microscopic analysis of the B-11((p)over-right-arrow,(p)over-right-arrow) reaction at E-p=150 MeV. II. Depolarization in elastic scattering from odd-A nuclei

The polarization-transfer coefficient D-nn(') in the elastic scattering of 150-MeV protons from B-11 has been measured in the angular range 5degree

Measurement and microscopic analysis of the B-11((p)over-right-arrow,(p)over-right-arrow) reaction at E-p=150 MeV. I. Inelastic scattering

Cross sections and analyzing powers for the B-11((p) over right arrow ,p(')) reaction have been measured using a 150-MeV polarized proton beam from the AGOR cyclotron at KVI. For the stronger inelastic transitions, also spin-flip probabilities have been extracted. To predict cross sections and spin observables a microscopic (coordinate space) model of elastic scattering has been used, whereas for inelastic scattering calculations were performed in the distorted-wave approximation. In the model calculations a medium-modified two-nucleon effective interaction was used and nuclear structure information was obtained from shell-model calculations in a complete (0+2)(h) over bar omega model space for parity-conserving transitions and a 1 (h) over bar omega shell-model description in the case of parity-changing transitions. With the help of these model calculations, spin-isovector parts of the M1 strengths for the negative-parity states at excitation energies of 2.125 MeV (J(pi)=1/2(-)), 4.445 MeV (J(pi)=5/2(-)), 5.020 MeV (J(pi)=3/2(-)), and 8.920 MeV (J(pi)=5/2(-)) have been extracted and compared to known Gamow-Teller strengths for the analog transitions to C-11

Performance of an ASD-8 based wire chamber readout system.

For the medium-energy proton polarimeter mounted at the focal-plane of the Big-Bite Spectrometer at Kernfysisch Versneller Instituut Groningen, a new wire-chamber readout has been developed. The charge-sensitive preamplifier is based on the ASD-8 B chip which has an input impedance of 115 Omega. This low impedance and the short integration time of 6 ns at a usable sensitivity of 5 fC allow high readout rates and low gas amplifications. This front-end circuit is mounted on all four multi-wire proportional chambers and on two vertical-drift chambers with 3872 wires in total. Measurements have been made using sources and intermediate energy protons. Special attention was given to determine the time-over-threshold properties of the circuit, The time-over-threshold capabilities of the readout system extend future applications to particle discrimination, or, in connection with other detector types, to energy-resolving readout, The operational performance of the readout system is presented

On the determination of polarization observables in proton-induced reactions using large-acceptance magnetic spectrometers

For proton-induced reactions, a formalism is presented to determine polarization observables using a focal-plane polarimeter in combination with a large-acceptance spectrometer, where also the effect of the scattering in the nondispersive plane of the spectrometer is taken into account. The inclusive proton-carbon analyzing power needed for the determination of spin observables was studied over a wide angular range and a new parameterization for this quantity was deduced. (C) 2003 Elsevier Science B.V. All rights reserved