Proportional Wire Chambers Research Articles

Progress report on the SLD cerenkov ring imaging detector

We describe test beam results from a prototype cerenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider (SLC). The system includes both liquid and gas radiators, a long drift box containing gaseous TMAE and a proportional wire chamber with charge division readout. Measurements of the multiplicity and detection resolution of cerenkov photons, from both radiators are presented. Various design aspects of a new engineering prototype, currently under construction, are discussed and recent R&D results relevant to this effort are reported.

X-ray position detection in the region of 6 μm RMS with wire proportional chambers

We have developed a MWPC system for X-ray detection with a position resolution in the region of 6 μm rms (14 μm fwhm). The performance with argon, krypton or xenon at pressures from 1 to 10 atm is explored for the X-ray energy range 5–25 keV. At a resolution of 6 μm rms the effects of photoelectron and Auger electron range, electronic noise, avalanche spread, lateral electron diffusion, as well as X-ray beam collimation, become of comparable magnitude. Their limiting effects on avalanche centroid fluctuation, and hence on position resolution, are investigated. The position resolution achieved in this work compares favorably with that of solid state devices.

Numerical results of calculations in three dimensions of the induced charge in MWPCs

An algorithm has been updated and vectorized for the calculation of induced charge distributions in proportional wire chambers. On a Cyber 205 Supercomputer the algorithm is fast and accurate. Results are in agreement with existing approaches and measurements. New details of the cathode charge distributions and wire signals as a function of the point charge position are presented.

Electron identification up to 100 GeV by means of transition radiation

We report on measurements with different transition radiation detector configurations, which were performed with the aim of pion-electron-discrimination in the momentum range between 1 GeV/ c and 100 GeV/ c. The test set-up consisted of four polypropylene fibre radiators with proportional wire chambers as photon detectors. We tested about 50 combinations varying the diameter of the fibre, the density of the radiators and the thickness of the chambers. Results of measurements performed at a DESY testbeam at energies between 0.6 and 6.6 GeV and of extrapolations to particle momenta up to 100 GeV/ c are discussed. At 95% electron efficiency a pion contamination of a few per cent can be achieved over the full energy range.

Ring Imaging Cherenkov Detector Prototype Results for E665 at Fermilab

A proportional wire chamber (PWC) with cathode pad readout has been used to measure the position of Cherenkov photons produced by the passage of a 100 GeV muon beam in a five meter long radiator at Fermilab. We observe, on average, 6.2 photo-electrons per muon using Tetrakis (Dimethyl Amino) Ethylene (TMAE) as the photo ionizing vapor for detecting Cherenkov photons and 3.5 photo-electrons using triethylamine (TEA). The observed radius resolution was 3mm FWHM for the TEA data and 5mm FWHM for the TMAE data. In both cases a CaF2 window transmitted the Cherenkov light from the radiator into the photon detector. The radiator gas was 20% argon and 80% helium producing Cherenkov rings with an average radius of 70mm. The detector described here offers the advantage of good timing resolution, (less than 100 nsec when using TEA), and high multi photon and multi ring reconstruction capability.

Signal development in wire chambers: The drift velocity of ions in gases

A geometrically simple wire chamber has been built, consisting of a brass tube with a 20 μm wire in its centerline. An analysis of avalanche signals allowed us to determine the position and the spread, due to diffusion of the cloud of positive ions, as a function of time. It was confirmed that the shape of signals from proportional wire chambers can be accurately reconstructed in terms of the linear relation between ion drift velocity ( w ) and the electric field strength ( E ): w = μE , where μ is the mobility of ions. In fact, the ion mobility is measurable with this simple tube.

A Dedicated Line-Processor as Used at the SHF

A hardwired trigger processor was used at the SLAC Hybrid Facility to find evidence for charged tracks originating from the fiducial volume of a 40" rapid-cycling bubble chamber. Straight-line projections of these tracks in the plane perpendicular to the applied magnetic field were searched for using data from three sets of proportional wire chambers (PWC). This information was made directly available to the processor by means of a special digitizing card. The results memory of the processor simulated read-only memory in a 168/E processor and was accessible by it. The 168/E controlled the issuing of a trigger command to the bubble chamber flash tubes. The same design of digitizer card used by the line processor was incorporated into the 168/E, again as read only memory, which allowed it access to the raw data for continual monitoring of trigger integrity. The design logic of the trigger processor was verified by running real PWC data through a FORTRAN simulation of the hardware. This enabled the debugging to become highly automated since a step by step, computer controlled comparison of processor registers to simulation predictions could be made.

A recoil proton detector using cylindrical proportional chambers and scintillator counters

A recoil proton detector consisting of three cylindrical proportional wire chambers and four layers of segmented scintillator counters is described. The device measures the recoil trajectory and energy in the momentum transfer range 0.06 < − t(GeV/c) 2 <1.4 . It has been operated successfully at Fermilab as part of the Tagged Photon Spectrometer, where it was calibrated with protons in the data and was used to form a high mass diffractive trigger.

Recent Results from the Cleo dE/dx System

The installation of the CLEO dE/dx particle identification system was completed last summer. DE/dx measurements are made with a pressurized gas proportional wire chamber system capable of making 117 ionization measurements. We report on measurements of relativistic rise and resolution from data taken on the T resonances and the nearby continuum. We describe the proven capabilities of the device in identifying hadrons in both the low and high momentum regions and electrons above 1 GeV/c.

An Integrated Amplifier and Sample-and-Hold Analog Multiplexer Module

The integrated amplifier and sample-and-hold analog multiplexer-ISHAM, is a proportional wire chamber analog readout module. It includes the front-end am plifier, the gated integrator and the sample-and-hold analog multiplexer. A density of 24 channels per module was achieved in a nonstandard multilayer P.C. board. Besides the above mentioned functions, the module provides: the control circuits for the Read-In and the Read-Out of the wire signals, the control circuits for the calibration of the 24 amplifiers, and the neutral trigger information. As an additional feature, the high voltage required by each wire is also supplied. The gain is 5V output voltage @ 20 pC input signal charge. The equivalent input noise charge is 4 × 10-15 C for the channel only and 6 × 10-15 for the entire system. The nonlinearity is better than 0.1% f.s. and the crosstalk is less than 1%. The Z-position resolution achieved is 1%.

The Application of Resistive Charge Division in Large Proportional Tube Chambers

A proportional tube chamber system has been constructed to instrument a high energy neutrino calorimeter at Fermilab. Each proportional wire chamber consists of a stack of extruded aluminum eight cell 1 × 8 extrusion with a 1/2 cell offset. With these modules 12' × 12', 16' × 16' and 24' × 24' chambers have been constructed. A novel resistive charge division system is used for the position measurement. This system, consists of a number of wires resistively connected in a paralled feeding into two amplifiers, one at each end. From a measurement of the pulse height difference normalized to the pulse height sum, the hit wire is uniquely determined thus giving a lateral position measurement.

Plans for brookhaven FASTBUS during the next π × 1016 nanoseconds

During this period new modules and devices will be built to be used in Experiment 749 at the A.G.S. Included will be /spl I.itilde/200 channels of A-D converters for Pb-Glass Cerenkov counters, 2000 channels of proportional wire chamber readout, cable segments, segment interconnects, a new unibus interface, and a new onsegment processor. These items and perhaps others will be ready by the end of 1981.

A triangular tube proportional wire chamber system

We report on the characteristics of the proportional tube chamber system which has been constructed for muon identification in the PEP-4 experiment at SLAC. The mechanical and electrical properties of the extruded aluminum triangular tubes allow these detectors to be used as crude drift chambers.

Early Operating Experience with the CLEO Detector

The CLEO detector operating at the Cornell Electron Storage Ring (CESR) consists of many elements: Inner Proportional Chamber, Inner Drift Chamber, Endcap Shower Chambers, Outer Drift Chambers, Cerenkov Counters, dE/dx Proportional Wire Chambers, Time-of-Flight Counters, Octant Shower Chambers, and Muon Chambers. We describe the initial performance of CLEO. Also recent physics results will be presented.

The Pressurized dE/dx System in the CLEO Detector at CESR

A unique part of the CLEO Detector at CESR is the pressurized wire proportional chamber system for particle identification using measurements of ionization loss (dE/dx) in gaseous argon. Each particle traverses the ∼ 80 cm thick detector and leaves 117 ionization samples. Data obtained from e+e- collisions at CESR in the 10 GeV center of mass energy region have been analyzed. Initial results showing the most probable ionization loss of hadrons and leptons as a function of their momenta will be presented. Also we describe the geometrical, mechanical and electrical construction of this device.

The Pressurized de/Dx System in the Cleo Detector at Cesr

A unique part of the CLEO detector at CESR is the pressurized wire proportional chamber system for particle identification using measurements of ionization loss (dE/dx) in gaseous Argon. Each particle traversing the ~80 cm thick detector leaves 117 ionization samples. Data obtained from e+e- collisions at CESR in the 10 GeV center-of-mass energy region have been analyzed. Initial results showing the most probable ionization loss of hadrons and leptons as a function of their momenta will be presented. We describe the geometrical, mechanical and electrical construction of this device.

Low Noise Charge Sensitive Amplifier with Low Input Impedance

This amplifier was designed for use in a large array of proportional wire chambers with charge division readout and for cathode readout of proportional chambers. The single stage high gain (104) amplifier with FET input has low component count, low cost, and a high packing density of 32 channels per double-sided P. C. board. Edge connectors are used for input, output, power and calibration signals. The on-board calibration system drives two independent groups of amplifiers through a range which is proportional to a distributed DC level over 3 orders of magnitude. The input and output signals are differentially driven for optimum noise rejection and interchannel isolation.

A Controlled Drift Space in Proportional Wire Chambers for Ionization Loss Measurement

This paper describes the use of cathode-window space of a proportional wire chamber for a better energy resolution. By providing a drift field in this gap, the whole thickness of the chamber was made sensitive. As a result, the pulse height resolution for minimum ionizing particles substantially improved over the conventional results.

Wire chambers

Proportional wire chambers and drift chambers are discussed with respect to their applications to high energy particle physics. Some results from a resistive cathode chamber and new ideas are presented.

An effective mass trigger at the Brookhaven multi-particle spectrometer (MPS)

An effective mass trigger for use at the Brookhaven Multiparticle Spectrometer (MPS) is described. It is a microprocessor based device using extensive fast memory attached to proportional wire chambers in the MPS magnetic field. It will select kinematic quantities unique to the reaction being studied, thereby permitting higher sensitivities and a reduction in data-processing costs for MPS experiments. The principles of operation for this trigger, and the results of simulations to assess its performance, are presented.