Some practical data on the first Townsend coefficient of organic vapour in avalanche counters
Abstract
The purpose of this investigation is the optimal use of Townsend's formula {α}/{p} = A exp[ {B}/{{(K}/{p)}}] for the estimation of the gas amplification of avalanche counters. The gas constants, A and B, were determined by the parallelplate avalanche counter (PPAC) method (Sernicki, Nucl. Instr. and Meth. A 288 (1990) 555), implemented at pressures ( p) successively increasing by 1 Torr. PPACs, filled with nheptane vapour, were used. The optimal solution was chosen from the three very precisely determined (at different boundary conditions) variants of data on the first Townsend coefficient (α) of nheptane in PPAC detectors. The chosen one is justifiable in the range of reduced electric field intensity ( {K}/{p}) values from 172.2 to 940 V/cm Torr, which includes the largest spans of applicable PPAC operating voltages. The results obtained were compared with the author's previous solutions (Sernicki, Nucl. Instr. and Meth. A 288 (1990) 555; Sernicki, Nukleonika 40 (4) (1995) 67).
 Publication:

Nuclear Instruments and Methods in Physics Research A
 Pub Date:
 February 1997
 DOI:
 10.1016/S01689002(97)009492
 Bibcode:
 1997NIMPA.399..347S