J. Špalek

Multi-hit drift time digitizer with one-nanosecond resolution

Abstract A multi-hit drift time digitizer is described (in the 16 μs range). It measures the time position of signals with an accuracy of 1 ns from a wide-gap drift chamber. A fast MECL memory (256 × 7 bits) in each information channel allows one to register up to 256 signals with a ⩾ 64 ns interval between pulses.

Electrodeless drift chamber in a flux of more than 105 particles per second per wire

Abstract Electrodeless drift chambers with drift lengths of 50 and 100 mm have been tested at a particle flux from 10 3 to 1.5 × 10 5 /s per wire. The efficiency remains high (>99%) up to a flux of 7 × 10 4 /s, but at a rate 1.5 × 10 5 /s it drops to 70%. The space-time linearity and spatial resolution do not change with the count rate. The recovery time after a high particle intensity is about 20 min. The characteristics do not change within many days of operation, even after large changes in the particle flux.

Measurement of electromagnetic shower position with an electrodeless drift chamber

Abstract Spatial resolution of a lead-glass shower detector was considerably improved by means of a converter and an electrodeless drift chamber as a coordinate detector. The coordinate of an electromagnetic shower was measured without a flash ADC; only a multi-hit TDC was used. A spatial resolution of 1.95 mm (r.m.s.) at an energy of 3 GeV was achieved. The efficiency in a relatively high shower count rate was checked.

Time projection chamber for experiments with heavy ions

Performance and characteristics of a large volume electronic track detector, time projection chamber (TPC), are described. The spatial resolution in the Z (vertical) direction is 0.2 mm, in the Y (horizontal) direction is 1 mm and the double track resolution in the Y- and Z-direction is 4.5 mm and 10 mm, respectively. A possible utilization of the TPC for experiments with heavy ions is discussed.

How to use electrodeless drift chambers in experiments at accelerators

Abstract Several types of wide-gap electrodeless drift chambers, including those with dimensions 1×1 m2, have been tested at accelerator beams. The chambers work with high efficiency (>99%), good spatial resolution (σ = 0.2−0.4 mm) and good linearity at flux rates up to 2×105 particles−1 per wire in spill, which corresponds to 3×106 particles/s m2 on colliders. It is shown that at the proper mode of operation beam intensity oscillations within the range of up to 4×105 particles/spill per wire do not affect the chamber efficiency.

Accuracy of electromagnetic shower position determination by a wide-gap drift chamber

The electromagnetic shower position was measured by a wide-gap drift chamber placed behind an active converter. Different methods for the shower-position determination based on MHTDC and flash ADC were used. A spatial resolution of 1.9 mm (rms) at an energy of 3 GeV and a converter thickness of 3X0 was achieved. The transverse charge distribution at different depths of the e.m. shower in the lead-glass was measured.

Tests of a time projection chamber module with delay line readout

The results of TPC tests in an accelerator beam are described. This chamber with a 800 x 350 x 60 mm3 sensitive volume is a module of a large TPC with dimensions 800 x 350 x 1600 mm3. The coordinate along the signal wires is determined by means of electromagnetic delay lines. The chamber operates with a track efficiency of > 90% and a spatial resolution of 0.2∼0.5 mm for the electron drift and 1–1.5 mm for the delay lines. The TPC module operates with high efficiency in the magnetic field with B = 1.5 T as well. The chamber was investigated using beams with intensities up to 106 particles/s. An electric gate, designed for the trigger mode of the chamber operation, was tested in the beam both with and without the magnetic field.