ITT F4000 (S50UVG) Ultra-Fast Vacuum Biplanar Phototube

ITT F4000 (S50UVG) Ultra-Fast Vacuum Biplanar Phototube

ITT F4000 (S50UVG) Ultra-Fast Vacuum Biplanar Phototube

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This is an ITT model 4000 (S50UVG) vacuum biplanar phototube for applications that require fast response monitoring of high intensity radiation. Ultraviolet grade glass entrance window for extended response to the ultraviolet region.

The F4000 model number refers to a family of 2.25 inch diameter high vacuum photodiodes. The plane parallel (biplanar) and coaxial electrode geometry combined with high voltage rating and low dark current make the F4000 series of tubes valuable for detecting and monitoring high intensity radiation. Linear output currents exceeding 5.0 amperes can be delivered to a terminated coaxial cable with a rise time of less than 5x10-10 seconds enabling the F4000 to be used for detailed examination of radiation over a minimum of 9 orders of magnitude in intensity within this gigahertz frequency range. With an S-5 cathode and associated scintillator, the F4000 can be used for monitoring high intensity, short duration gamma radiation.


Effective Photocathode Diameter

44.5 mm

Major Diameter

57.2 mm

Rise Time

500 picoseconds

Effective Photocathode Area

1548 mm2


48.3 mm

Anode Mesh Openings per 25.4 mm


Anode Mesh Optical Transmission

80 %

Resistance of Anode Mesh

0.5 Ω

Photocathode Spectral Response


Typical Operating Voltage

2.5 kV

Typical Photocathode Luminous Sensitivity [µA/lm]


Photocathode Peak Radiant Sensitivity [A/W]


Maximum Peak Current Output

5 A

Maximum Average Current Output

75 μA

Deviation From Linearity

10 %

Interelectrode Capacitance

1 pF

Maximum Dark Current

5 nA


63.8 grams