Abstract
The drift velocity, w, of excess electrons as a function of the applied uniform electric field, E, in liquid tetramethylsilane (TMS), 2,2,4,4-tetramethylpentane (TMP), tetramethyltin (TMT), and in mixtures of TMS with TMP (molar ratio, M = 1.31/1) and n-pentane (M = 102/1; 17/1; 5.6/1) has been measured up to E-values of ∼ 105 V cm-1 or density (N)-reduced ele ctric held E/N-values of ∼ 3 × 10-17 V cm2. The maximum w attained for these liquids, and the corresponding values of E are: 7.2 × 106 cm s-1 at 125 kV cm-1 for TMS, 6.0 × 106 cm s-1 at 75 kV cm-1 for TMS, 2.6 × 106 cm s-1 at 115 kV cm-1 for TMP, 3.2 × 106 cm s-1 at 105 kV cm-1 for TMS/TMP (M = 1.31/1), 6.8 × 106 cm s-1 at 105 kV cm-1 for TMS/n-pentane (M = 102/1), 6.8 × 106 cm s-1 at 145 kV cm-1 for TMS/n-pentane (M = 17/1), and 4.9 × 106 cm s-1 at 145 kV cm-1 for TMS/n-pentane (M = 5.6/1). The thermal-electron mobilities in the above liquid media are respectively 119.3, 85.7, 31.8, 39.1, 118, 85, and 47.6 cm2 s-1 V-1. Also, w was measured as a function of E/N for TMS, TMP, and neopentane vapors at room temperature and is compared with that in the corresponding liquids. Properties of these media which make them desirable for radiation detectors are discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 575-582 |
| Number of pages | 8 |
| Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
| Volume | 294 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 15 1990 |
Funding
Hydrocarbon liquids and gases (and their mixtures with rare gases) are increasingly used as detector media in high-energy-physics radiation detectors (e.g. calorimeters and muon chambers) . Room-temperature liquids, suitable for calorimeter detectors [1-41 (especially those for the superconducting super collider, SSC), should be fast (have short electron collection times) and sensitive (have good energy resolution and particle identification properties) [5,61, while the hydrocarbon/ rare-gas mixtures used in gas-filled drift chambers [71 should have electron transport parameters (electron drift velocity, w, and longitudinal, D L , and transverse, Dr , electron diffusion coefficients) which optimize the operating characteristics of the detector [8-101 . In order for the response of the detector to be fast, the excess electrons in these detector media must be either free, as in gases, or s a" " s c a_ " ~ quasifree, as in dense gases and liquids lor wrucn thhee Research sponsored by the C ffice of Naval Research and the U.S . Department of Energy under, respectively, Contracts no. N00014-89-J-1990 and DE-AS05-76ER03956 with the University of Tennessee, and by the Office of Health and Environmental Research, U .S. Department of Energy, under Contract no . DE-ÁC05-840821 with Martin Marietta Energy Systems, Inc. Also, Dept . of Physics, University of Tennessee, TN 37996, USA .