Everhart–Thornley detector
Everhart–Thornley detector
The Everhart–Thornley detector (ET detector) is a type of scintillation detector used in scanning electron microscopy (SEM) to collect secondary electrons and produce an image. It was invented by Thomas Everhart and Richard Thornley in the early 1960s.
Principle of Operation[edit | edit source]
The Everhart–Thornley detector operates by attracting secondary electrons emitted from the surface of a specimen when it is bombarded with a focused beam of primary electrons. These secondary electrons are then accelerated towards a scintillator by a positive bias applied to a collector grid or a Faraday cage. The scintillator emits photons when struck by the secondary electrons. These photons are then guided through a light pipe to a photomultiplier tube (PMT), where they are converted into an electrical signal. This signal is amplified and used to modulate the brightness of a display, creating an image of the specimen's surface.
Components[edit | edit source]
The main components of the Everhart–Thornley detector include:
- Scintillator: A material that emits light when struck by electrons.
- Photomultiplier tube (PMT): A device that converts light into an electrical signal and amplifies it.
- Collector grid/Faraday cage: A positively biased component that attracts secondary electrons.
- Light pipe: A medium that guides photons from the scintillator to the PMT.
Advantages[edit | edit source]
The Everhart–Thornley detector is highly efficient in collecting secondary electrons, which makes it ideal for producing high-resolution images of the surface topography of specimens. It also has a fast response time, which is beneficial for dynamic studies.
Applications[edit | edit source]
The ET detector is widely used in various fields, including:
Related Pages[edit | edit source]
- Scanning electron microscope
- Secondary electron
- Scintillation detector
- Photomultiplier tube
- Thomas Everhart
- Richard Thornley
See Also[edit | edit source]
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
|
WikiMD's Wellness Encyclopedia |
| Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Translate this page: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
தமிழ்,
తెలుగు,
Urdu,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
বাংলা
European
español,
Deutsch,
français,
Greek,
português do Brasil,
polski,
română,
русский,
Nederlands,
norsk,
svenska,
suomi,
Italian
Middle Eastern & African
عربى,
Turkish,
Persian,
Hebrew,
Afrikaans,
isiZulu,
Kiswahili,
Other
Bulgarian,
Hungarian,
Czech,
Swedish,
മലയാളം,
मराठी,
ਪੰਜਾਬੀ,
ગુજરાતી,
Portuguese,
Ukrainian
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD
