Gas tube for background studies
2 inch O.D. copper tube
0.032 inch wall => 2.46 cm inside radius
4 mil BeCu wire
45 cm overall length
0.063 inch single sided circuit board on each end.  Circuit board is recessed about 1 mm inside the
tube.  Copper side of circuit board is on the outside.  Edge of circuit board is soldered to the tube to
make the gas seal.
Effective length of gas volume is about 44.5 cm.
845 cc effective gas volume
Gas is Argon/CO2 (80%/20%)
Fill pressure was about 2 mm of water above ambient pressure.  Ambient pressure was not measured.
Argon is 1.7837 g/l (from CRC)
CO2 is 1.977 g/l
Density of mix is 1.82 g/l => 1.82 g/l * 0.845 l = 1.54 g of gas

1 Gy = 1 J/kg
1 Gy = 100 rads
1 rad = 1E-2 J/kg

26 eV for Argon
33 eV for CO2
(26*0.8) + (33*0.2) = 27.4 eV for the average energy to create an ion pair
1 J = 6.25E18 eV
=> 2.28E17 ion_pairs/kg/Gy
=> 1 Gy = 0.0365 C/kg    for Ar/CO2 (80%/20%) at STP

1 Mrad = 2E4 Gy => 730 C/kg/Mrad
730C/kg/Mrad = 1.33 C/l/Mrad

=> 1.33 C/l/Mrad * 0.845 l = 1.12 C/Mrad   for our tubes (if gain of tube equals 1)



100k ohm resistor on the high voltage line going to the car.
10uA = 10E-5 Amps
10E-5 Amps * 10E5 ohms = 1V
1uA => 1 rad => 0.1V => 6.25E12 e-/sec