A high current focused electron ring-beam column design
| العنوان: | A high current focused electron ring-beam column design |
|---|---|
| المؤلفون: | Pranesh Balamuniappan, Anjam Khursheed, Wei Kean Ang |
| المصدر: | International Journal of Modern Physics A. 34:1942002 |
| بيانات النشر: | World Scientific Pub Co Pte Lt, 2019. |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | Physics, Accelerator physics, 0303 health sciences, Nuclear and High Energy Physics, business.industry, Astronomy and Astrophysics, 02 engineering and technology, Electron, 021001 nanoscience & nanotechnology, Ring (chemistry), Electron spectroscopy, Atomic and Molecular Physics, and Optics, law.invention, 03 medical and health sciences, Optics, law, Beam column, Cathode ray, Physics::Accelerator Physics, Electron microscope, Current (fluid), 0210 nano-technology, business, 030304 developmental biology |
| الوصف: | There are many applications in electron microscopy, electron spectroscopy, as well as accelerator physics that require the combination of minimizing a focused electron beam’s probe size while maximizing its beam current. This paper describes how this can be done through the use of annular focused electron beam column designs, where an electron beam is propagated and focused in the form of a ring beam. For probe semi-angles of [Formula: see text] radians, a column consisting of two identical electric sectors and two identical focusing lenses functioning with odd symmetry will be presented, together with a wide-angle cold field emission gun design. The column is designed to cancel energy dispersion while limiting geometric aberrations to the third order at the point of final focus. This design is predicted to have over two orders of magnitude higher beam current than the corresponding conventional on-axis focused electron beam columns for the same final probe size. For a 1.2 keV annular electron beam, simulation results predict a spot radius of 4.8 nm at a working distance of 3.4 mm, final beam angle of [Formula: see text] mrad, and energy spread of [Formula: see text] eV. |
| تدمد: | 1793-656X 0217-751X |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_________::1d9ce65bd303e37814659b240c218382Test https://doi.org/10.1142/s0217751x19420028Test |
| رقم الانضمام: | edsair.doi...........1d9ce65bd303e37814659b240c218382 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 1793656X 0217751X |
|---|