4 results about "Electron pulse" patented technology

This invention belongs to the field of precision scientific instruments and vacuum technology, and discloses a liquid ultrafast electron diffraction experimental station integrating a THz diagnostic structure. The station includes a vacuum chamber, a double-sided flange arranged upstream of the liquid film location along the electron beam transmission path, a position adjustment structure, a vacuum differential pipe, and a THz diagnostic structure. The double-sided flange is fixed between the vacuum pipe flange outside the vacuum chamber and the vacuum chamber itself. The position adjustment structure is axially and adjustablely fixed coaxially within the double-sided flange. The vacuum differential pipe is coaxially fixed within the position adjustment structure and passes through the sidewall of the vacuum chamber. The THz diagnostic structure is positioned between the vacuum differential pipe and the liquid film location. This invention integrates a vacuum differential system and a THz electron beam diagnostic system in situ within a single vacuum chamber, achieving synchronous compatibility between liquid-phase ultrafast electron diffraction and electron pulse time-domain diagnostics, ensuring the accuracy of time-resolved assessment of liquid-phase structure dynamics.

An electron beam source includes a vacuum chamber containing a cathode and an anode separated by a vacuum gap forming a local full-voltage capacitive structure storing electrical energy at an operating voltage. A high-voltage power supply charges the capacitive structure without an intervening Marx generator, linear transformer driver, Tesla transformer, pulse-forming network, or pulse-forming transmission line. A triggering arrangement initiates electron emission to produce electron pulses traversing the vacuum gap, with discharged electrical energy transferred predominantly to electrons crossing the gap. In some embodiments, the local capacitive structure stores a majority of total electrical energy stored at the operating voltage in capacitances directly coupled between conductors at cathode and anode potentials. Multi-beam configurations, beam steering, passive synchronization, and contamination management features may be included.

The application aims at solving the technical problem that the time resolution of the system is difficult to break through the technical barrier of 100 femtoseconds due to the phase jitter between the radio frequency field and the pump laser in the prior art, and providing an ultrafast electron pulse non-jitter static magnetic time compression device and compression method; the device comprises a femtosecond laser, an ultrafast electron gun, an electron beam collimation transmission assembly, an Omega type static magnetic time compression assembly, an electron beam aberration correction and final stage focusing assembly and a sample cavity which are sequentially arranged on the light output path of the femtosecond laser; the Omega type static magnetic time compression assembly is used for introducing an energy related time delay to the ultrafast electron pulse, compensating the initial time chirp of the electron pulse, and compressing the pulse width of the ultrafast electron pulse to below 100 femtoseconds. In the process of electron pulse acceleration and pulse compression, the device does not need to consider the time jitter between the radio frequency field and the femtosecond laser, and can maximize the time resolution of the ultrafast characterization instrument.

An electron beam pulser suitable for SEM systems directs ≤30 keV electrons through a stripline kicker. RF waves or voltage pulses deflect the beam to periodically impinge on an aperture, thereby creating electron pulses from 100 fs to 100 ns in width. In RF embodiments, the RF frequency is tuned to provide 180-degree phase slippage between the RF and the electron beam, thereby generating pulse repetition rates up to 20 GHz without divergence. The RF can be reverse propagated through the kicker to reduce kicker size and / or increase the maximum pulse repetition rate. Voltage pulse embodiments provide flexible pulse widths and timing with repetition rates up to 1 GHz. A DC bias is applied to enable electron transit only during the voltage pulses, or offset voltage pulses of opposite sign can produce narrow electron pulses only during voltage pulse overlap. The EMMP can be synchronized for pump-probe experiments.