Ludlum Model 43-68 100cm^2 gas proportional detector

APPLICATION: alpha beta radiation survey
RADIATION DETECTOR: rechargeable gas proportional
EFFICIENCY (4π): 20% - ²³⁹Pu; 30% - ⁹⁹Tc; 30% - ⁹⁰Sr/⁹⁰Y; 15% - ¹⁴C; < 1% - gamma

SIMULTANEOUS ALPHA/BETA COUNTING: 17.5% - ²³⁹Pu; 20% - ⁹⁹Tc; 20% - ⁹⁰Sr/⁹⁰Y

WINDOW: 0.8 mg/cm² aluminized mylar (other thickness available)
WINDOW AREA:126 cm² (19.5 in²) active, 100 cm² (15.6 in²) open

RECOMMENDED COUNTING GAS: P-10 (10% methane, 90% argon)

GAS RECHARGE: will operate on a static charge for at least 15 hours with 39 in. (1 m) cable; 5-hour static charge if connected to a simultaneous alpha/beta measuring instrument
GAS CONNECTORS: double end quick disconnect
BACKGROUND: alpha < 7 cpm (when operating on the alpha only plateau region), beta-gamma typically 350 cpm or less (10 microR/hr field)
COMPATIBLE INSTRUMENTS: Ludlum Models 12, 16, 18, 2000, 2200, 2221, 2224-1, 2241-2, 2350-1, 2360
OPERATING VOLTAGE: alpha - typically 1100-1400 volts, beta/gamma - typically 1600-1800 volts
COUNTER THRESHOLD SETTING: typically 2-5 mV
SIZE: 3.9 x 4.6 x 7.8 in. (10 x 11.7 x 19.8 cm) (H x W x L), with handle
WEIGHT: 2 lb (0.9 kg)