Method and apparatus for fast laser pulse detection using gaseous plasmas

Patent · Tue May 08 04:00:00 EDT 1984

OSTI ID:6456712

McLellan, E J; Webb, J A

The method and device of the instant invention is a detector of pulsed laser radiation which utilizes the electromotive force generated by the plasma formed when such radiation is focused onto a surface (1). Measurements are made with a 10.6..mu..m CO/sub 2/ laser capable of producing peak intensities of 10/sup 13/W/cm/sup 2/ when directed through a converging lens (2). Evacuated detector response to such laser intensity is 1 kV signal peak amplitude and subnanosecond risetimes into a 50..cap omega.. load (3). Detector performance is found to be greatly altered with the introduction of a background gas (4). For example, with one atmosphere of air, the detector produces prompt signals of the order of 1 V with subnanosecond response for pulse trains lasting 100 ns. With argon, krypton, or zenon at pressures of the order of 10 torr, the detector generates ''trigger pulses'' of about 250 V amplitude and 0.2 ns risetimes. Such detectors are quite robust when irradiated with high intensity laser radiation and are useful for qualitative laser beam monitoring.

• Assignee: Dept. of Energy
• Patent Number(s): US 4447151
• OSTI ID: 6456712
• Country of Publication: United States
• Language: English

Related Subjects

440101* -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ARGON
BEAM MONITORING
DESIGN
ELECTROMAGNETIC RADIATION
ELECTROMOTIVE FORCE
ELEMENTS
FLUIDS
FUNCTIONS
GASES
KRYPTON
LASER RADIATION
LASERS
MEASURING INSTRUMENTS
MONITORING
NONMETALS
PLASMA
PULSE RISE TIME
PULSE TECHNIQUES
RADIATION DETECTORS
RADIATIONS
RARE GASES
RESPONSE FUNCTIONS
SIGNALS
TIMING PROPERTIES
XENON