New Design for a Gas-Flow Proportional Counter

This paper describes a compact design for a gas‐flow proportional counter. Externally adjustable end plates for correcting the electric field allow pulse‐height distribution curves comparable with those from long counters, although the counting volume is 1¼ in. in diameter and $1\frac{1}{16}$ in. long. A transistorized preamplifier inside the counter case provides clear pulses with low background in a low impedance line. The gas‐flow proportional counter described here has three significant features: (1) low noise, approximately 1% of the Fe K_α pulse height; (2) low impedance output from the first preamplifier; (3) energy spread less than 20%, in spite of short length and large diameter.