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24 Cards in this Set
- Front
- Back
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First Gen NVG was introduced in the late _____,with the development of the _________ _____ used by snipers in vietnam. |
1950's : Starlight Scope |
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These systems attained high level gains by means of a _____ _____ _____________. |
Three Stage Configuration |
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The _____ ___________ ____ relied solely on a ____________/________ screen stack array to achieve _____________ or ____. |
Image Intensifier Tubes: Photocathode: Phosphor: Amplification, Gain |
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The 3 stage coupling provided gains in the range of _____ times that possible from a single stage tube. |
40,000 |
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First Gen tubes were very durable and had a very long life, well into the _____ hour range. |
10,000 |
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3 major deficiencies of Gen 1 NVG |
1)Extremely susceptible to blooming 2)Required relatively high voltages to attain nessary energy levels for light amplification 3)Size, about a foot long |
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Definition of Blooming |
Tendency for tubes to degain and shut down if a bright light source appears in the devices field of view. |
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An image intensifier tube is an _______-_______ device used to detect and intensify ______ in the _______ and ____ infared region of the ________________ ________. |
Electro-Optical Energy Visible and Near Electromagnetic Spectrum |
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The internal components of an image intensifier tube include what 3 things? |
Photocathode Microchannel Plate Phosphor Screen |
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__________ energy from the terrain enters the NVG and is focused on the _________ _____ on to the ____________. |
Reflective Objective lense Photocathode |
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Photocathode is sensitive to portions of both the _______ and ____ IR spectrum. |
Visible and Near |
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2nd Gen I2 Tubes were developed in the late _____. |
1960's |
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2nd Gen were the first tubes small enough to be ______ _______. |
Head Mounted |
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The ____________ _____ was first introduced with the Gen 2 I2 tube |
Microchannel plate |
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Main differences between Gen 1 and Gen 2 I2 tubes |
Less susceptible to blooming(more concentrated) Smaller in size |
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What are the 2 major changes the defined the transition from Gen 2 to Gen 3 I2 tubes? |
1) Gallium arsenide photocathode 2) Aluminum oxide protective coating on the input side of the microchannel plate. |
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The multi alkali photocathode (S20) has a broadband spectral response range over the visible and near IR spectrum of ___ to ___ __________. |
400 to 900 nanometers |
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The introduction of a GaAs photocathode significantly changed the spectral sensitivity of the NVG to ____ to ____ with a peak sensativity between ____ to _____ nanometers. |
400 - 900 600 - 900 |
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What is the purpose of the aluminum oxide film ? |
To protect the photocathode from ion bombardment created by the MCP |
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The addition of the aluminum oxide film _________ service life of the 3rd Gen I2 tubes to _______ ____ ______ _____. |
Increased Greater than 10,000 hours |
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Only consequence encountered with the introduction of the ________ _____ ____ is a _______ increase between the ____________ and the ____________ _____. |
Aluminum oxide film Voltage Photocathode Micro channel plate |
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The voltage increase requires increased _______ between the Photocathode and Micro channel plate to _______ _______. |
Spacing Prevent arcing |
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Omnibus- VI I2 tubes include a ______ ________ _____ ____ which decreases halo size from ______ to_____ |
Thinner aluminum oxide film 1.25mm to 0.7mm |
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A ___ moon disc positioned at ___ above the horizon is equivalent to ______ lux illumination. |
20% 30° 0.0022 |
