Parallel Plate Avalanche Chamber Research Articles

The parallel plate avalanche chamber as an endcap detector for time projection chambers

We have investigated the possibility of using a parallel plate avalanche chamber as endcap detector for the time projection chamber instead of a multiwire proportional chamber. Such a solution has several advantages. The positive ion feedback in the drift volume and the E× B distortions are considerably reduced; moreover, space charge effects in the detector are smaller allowing higher rates and probably higher gains without deterioration of the energy resolution. Detection of the fast electron signal component allows to obtain two-track separation in the drift direction of 1.5–2 mm; the localization in the two other directions can be realized with accuracies better than 100≃m and with typical two-track separations between 1 and 2 mm. The detector is realized exclusively with grids and thick wires, thus eliminating breakdown problems.

High gain multigap avalanche detectors for cerenkov ring imaging

We report on a continuing study of multigap parallel plate avalanche chambers, primarily as photoelectron detectors for use with Cerenkov ring imaging counters. By suitable control of the fields in successive gaps and by introducing screens to reduce photon feedback to the cathode the gain may be increased considerably. We have obtained gains in excess of 6 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> for photoelectrons with a good pulse height spectrum and expect to increase this further. We discuss the use of resistive anodes to give avalanche positions in two dimensions by charge division.