2 results about "Drift velocity" patented technology

This invention discloses a plasma local current measurement device and method based on optical methods, belonging to the field of optical measurement technology. The device includes: a high-energy pulsed laser, a beam splitter, a photodiode for triggering an ICCD camera, a beam sampling mirror for providing optical signals to the photodiode, a focusing lens for focusing the high-energy pulsed laser, a pulsed power device for generating Z-pinch plasma, a beam collector, an achromatic lens for collecting scattered light, a reflective grating spectrometer, an ICCD camera, and a Mach-Zehnder interferometer. Electron density distribution, electron temperature, ion temperature, plasma velocity, and relative electron-ion drift velocity can be simultaneously obtained through plasma interference fringe images and Thomson scattering spectra. The local current at the measurement point is obtained by multiplying the electron density, electron charge, and relative electron-ion drift velocity at the measurement point.

This invention proposes a velocity-controlled graphene non-reciprocal near-field thermal radiation measurement device and method, belonging to the fields of nanoscale thermal management and photonics technology. A first graphene plate and a second graphene plate are placed parallel to each other in a high-vacuum cavity, with a nanoscale vacuum gap between them. A macroscopic displacement platform is connected to the first graphene plate to control its macroscopic movement velocity along the interface direction. A precision DC power supply is connected to the second graphene plate to inject current to induce microscopic drift velocity of its internal charge carriers. A high-precision temperature sensor is in contact with both graphene plates to monitor their temperature. A near-field heat flux meter is located on the back side of the second graphene plate to measure the radiative heat flux passing through the gap. A calculation and control unit is connected to the macroscopic displacement platform, the precision DC power supply, the high-precision temperature sensor, and the near-field heat flux meter to coordinate and control the velocity parameters and collect and process heat flux data.