1 / 9

Ágúst Valfells Science and Engineering

SIZE MATTERS –ELECTRON BEAMS AT THE MICROSCALE. Ágúst Valfells Science and Engineering. vacuum electronics. solid state integrated circuit. vacuum tubes. high power microwaves. tubes are expensive to make must maintain vacuum conditions. integrated circuits are inexpensive

rosa
Download Presentation

Ágúst Valfells Science and Engineering

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SIZE MATTERS –ELECTRON BEAMS AT THE MICROSCALE Ágúst Valfells Science and Engineering

  2. vacuum electronics solid state integrated circuit vacuum tubes high power microwaves tubes are expensive to make must maintain vacuum conditions integrated circuits are inexpensive solid state electronics put limit on frequency and efficiency 105 Vacuum electronics 104 CW power [W] 103 102 Solid state 101 Frequency[GHz] 100 1 10

  3. vacuum microelectronics Credit: Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley Credit Paul Scherrer Institute nanotube radio field emission array

  4. possible advantages of vacuum microelectronics high efficiency due to limited interaction with bulk structure tolerance of high temperature and radiation short path length decreases vacuum requirements small length scales indicate possible high frequency f ~ 1 / L rapid switching via field emission

  5. electron beams – emission Thermionic emission. Field emission is due to tunneling of electrons through the potential barrier. It is the dominant emission mechanism at high field strength. Local enhancment of the electric field can lead to higher emission density. Photoemission. wikipedia Field emission Accurate assesment of surface field is difficult –much fudging.

  6. surface irregularities Credit JoonilSeog electric field is enhanced at protrusions surface uniformity decreases at shorter length scales variations in composition are also important

  7. electron beams - dynamics electrons in vacuum region interact with surrounding structure electrons interact with each other - nonlinearity THz bunching due to space-charge limited emission. An intriguing possibility for generating radiation. - +

  8. issues of interest at the vacuum scale emission physics: i-v characteristics; energy and angular distribution of electrons from surface; accurate modeling –needs and limitations. beam dynamics: emittance and brightness; long range and short range Coulomb interaction; transit time, frequency response. electron backscattering and secondary electron emission. quantum effects. irregularity of surfaces; shot noise; cavity Q; surface roughness and skin depth

  9. computational vacuum microelectronics at RU Microscale works to our advantage – full fidelity modeling 50 nm 1 nm 10 nm

More Related