NAVAL RESEARCH LABORATORY RESEARCH REACTOR. PART III. AN EIGHT-DECADE LOGARITHMIC AMPLIFIER FOR NUCLEAR REACTOR INSTRUMENTATION

Technical Report · Sun Sep 01 04:00:00 EDT 1957

OSTI ID:4342678

Wall, G F; Young, M P

dynamic range of eight decades of current (10/sup -11/ to 10/sup -3/ amp), good accuracy, a high degree of stability with changes in heater voltages, and requires no range switching. The amplifier will give an output which is proportional to the logarithm of its input current, and the circuit employs a pentode as the logarithmic element. The amplifier has been used satisfactorily in a signal channel which provides power level and period information continuously for the NRL Research Reactor control system. Radiation detector current is fed directly to the control grid of the logarithmic element. A feedback amplifier holds the plate current constant by adjusting the screen grid voltage. The adjusted screen grid voltage is also used to drive a recorder directly. Although designed specirically for the NRL Research Reactor control system, the amplifler should find many uses in the field of nuclear instrumentation. (auth)

• Research Organization: Naval Research Lab., Washington, D.C.
• NSA Number: NSA-12-003256
• OSTI ID: 4342678
• Report Number(s): NRL-5025
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AMPLIFIERS
CONTROL SYSTEMS
ELECTRON TUBES
INSTRUMENTS
PHYSICS
POWER
REACTORS
RESEARCH REACTORS
SIGNALS