T. Lyons

The iron calorimeter and muon identifier for SLD

Abstract The iron flux-return structure for the SLC Large Detector (SLD) has been instrumented with plastic streamer tubes covering an area of about 4500 m 2 , to provide muon identification plus energy measurement of hadron showers. A description is given of the production techniques used to construct this large detector system, with an emphasis on the methods by which high reliability and a small number of defects in the completed assembly were ensured.

The limited streamer tubes of the SLD

Abstract A large hadron calorimeter and muon tracking device using plastic streamer tubes has been constructed in the iron flux-return structure for the SLD detector at SLAC. Various studies of the operating characteristics of the streamer tubes of this system are presented. Emphasis is placed on the tracking capabilities of the device and on the optimization of the high voltage and readout electronics.

A nonflammable gas mixture for plastic limited streamer tubes

Abstract The gas mixtures presently used in plastic limited streamer tubes (“Iarocci tubes” or LSTs) have a high hydrocarbon content and are very flammable when mixed with air, posing a potential safety hazard in modern large underground experiments. The SLD Warm Iron Calorimeter group has therefore made an extensive investigation of nonflammable ternary mixtures based on CO 2 . Ar and various hydrocarbons. We present here brief results of this research. In particular, we describe a detailed study of a nonflammable gas mixture (2.5% Ar: 9.5% iC 4 H 10 : 88% CO 2 ) which indicates that this mixture has properties comparable to those of the two commonly used gases (25% Ar: 75% iC 4 H 10 and 21% Ar: 37% nC 5 H 12 : 42% CO 2 ) and could successfully replace these mixtures in LST-based tracking devices and hadron calorimeters.

Hadron showers in a low-density fine-grained flash chamber calorimeter

Abstract Hadronic showers at six incident particle energies from 33.8 to 415.4 GeV have been studied using the low-density fine-grained flash chamber calorimeter of the Lab C neutrino detector at Fermilab. Transverse distributions of unprecedented fine granularity have been obtained for a range of depths in the shower. Longitudinal energy distributions have been compared with those from iron-scintillator detectors. Some differences are observed which may be attributable to the different relative sensitivity of the two detector types to electromagnetic and hadronic shower components. Both longitudinal and transverse distributions have been parametrized. Fluctuations in energy deposition have been studied. The relative size of the fluctuations is largest near the starting vertex and in the tail of the shower, and falls slowly with increasing beam energy. Correlations between energy deposition in neighboring parts of the shower are observed, and anticorrelation is seen between energy deposition in the peak and in the tail of the shower. Containment lengths and widths have also been measured and parametrized.

The SLD calorimeter system

A brief description is given of the SLD calorimeter system, with emphasis on the iron calorimeter/muon identifier. Design choices and expected performance are summarized.

Erratum to “hadron showers in a low-density fine-grained flash chamber calorimeter”☆

Abstract Our recent paper ∗ described an analysis of the energy deposition in hadronic showers at six incident particle energies from 33.8 to 415.4 GeV using the low-density fine-grained flash chamber calorimeter of the Lab C neutrino detector at Fermilab. More recent work on the subject has led us to revise some of the results presented for energies above 200 GeV. We present here revised results for the longitudinal and transverse energy deposition, and new coefficients for the parametrization of these curves.

The Construction and Performance of Large Flash Chambers

The constuction and performance of 12¿ × 12¿ flash chambers used in a 340 ton neutrino detector under construction at Fermilab is described. The flash chambers supply digital information with a spatial resolution of 0.2¿, and are used to finely sample the shower development of the reaction products of neutrino interactions. The flash chambers are easy and inexpensive to build and are electronically read out.

The pad readout electronics of the SLD warm iron calorimeter

Abstract The design of the pad readout electronics of the Warm Iron Calorimeter for the SLD detector at SLAC, consisting of about 9,000 analog channels, is described. Results of various tests performed during the construction, installation and commissioning of the electronics mounted on the detector are presented.

Construction and Operation of an Electromagnetic Shower Detector

An electromagnetic shower detector consisting of lead glass blocks and scintillator hodoscopes was constructed. During calibration runs detector resolutions were measured for single incident electrons. Performance of the detector for ¿° and multi-photon showers, including sizable backgrounds, was studied during actual data runs.