THE MANSON ABSOLUTE PHOTON COUNTING SYSTEM FOR ULTRASOFT X-RAYS The Manson Model 04 Gas Flow Proportional Counter is shown below in its standard form, mounted on the Manson Model PAL-01 Pulse Amplifier. This combination may be mounted directly on the exit flange of a spectrometer by pressing the window mount against a size 2-014 O-ring set in an adapter flange, around the exit port. The output of the Model PAL-01 will drive a 50 ohm coax cable with a nominal termination of 1000 ohms. The combination shown is also vacuum-compatible. The counter is shown with 3/8" end shields, through one of which it is mounted on the amplifier. Optionally, one end may be terminated in a 3/4" shield which will provide a mounting surface for a standard MHV or SHV connector, for remote amplifier use.

SPECIFICATIONS

MODEL 04 PHOTON COUNTER CATHODE (BODY): Nickel plated brass. 1.95 cm ID, cylindrical interna1 symmetry. OA length: 7.3 cm. ANODE: 50 micron diem stainless steel. WINDOW: VYNS, 27 ugms cm-2, on 60% transmission 400 mesh screen. Apertures 1.5mm x 10mm, 3mm x 10mm & 4.5mm x 10mm, for maximum diff. pressures of 800, 400, and 200 Torr, respectively. Interna1 pressure must exceed pressure outside the window. GAS ABSORPTION PATH: 2.05 cm max. MODEL PAL-0lB PULSE AMPLIFIER The input stage is a JFET-bipolar cascode, followed by quasi-Gaussian double diff. and integrating filters with 0.75 usec time constants. A 20:1 variable attenuator into a gain-of-20 line driver provides direct-coupled output to customer's circuits. CHARGE SENSITIVITY: -2 x 10+14 V Coul.-1 NOISE REFERRED TO INPUT: 650 e , rms, with photon counter attached. PULSE SHAPE: Bipolar, positive lobe leading, 6 usec pulse duration. POWER REQ'D: 35 ma at +15V, 25 ma at -15V. LINEAR OUTPUT RANGE: 0 to 8 V into 1000 ohm load.

MODEL 2 GAS FLOW CONTROL SYSTEM GENERAL CONSTRUCTION: Mounted on a standard 19" x 7"- aluminum panel, with brass valves and compression fittings, and 1/4" OD polyethylene and rubber tubinq. The rear panel is punched for alternate mountinq of tubinq connections to the gas supply, exhaust pump, and experiment. INPUT FLOW RATE: A fixed capillary flow restrictor limits the flow to 5 cc min-1 at NTP from customer's reqglator set at 1 PSI gauge, with the system at 100 Torr. PRESSURE CONTROL AND EXHAUST: Very fine needle valve in exhaust line establishes stable pressure, balanced against the fixed input flow. System internal volume of 76 cc, including 6' lines and counter, allows rapid equilibration of pressure when re-setting a new value. Exhaust is to customer's small mechanical pump. When using methane or propane, or other explosive gas, the usual precautions must be taken to vent the exhaust line. PRESSURE INDICATION: Panel mounted modified vacuum gauge. Scale is manually set to zero indicated absolute pressure, referenced to the atmospheric pressure, with the counter and system evacuated. Scale is calibrated to 400 Torr, +/- 5% of readinq above 40 Torr. Photo of gas system.