Study of Photocathode Properties in Ultra-High Speed Systems for Registration of the Short-Time Processes
Tech Area / Field
- INF-ELE/Microelectronics and Optoelectronics/Information and Communications
3 Approved without Funding
Kurchatov Research Center / Institute of Nuclear Fusion, Russia, Moscow
- VNIIEF, Russia, N. Novgorod reg., Sarov\nResearch Institute of Optical and Physical Measurements, Russia, Moscow
- Lawrence Livermore National Laboratory / University of California, USA, CA, Livermore\nCNRS / Ecole Polytechnique, France, Palaiseau
Project summaryElectron-optical registration method is widely used in the molecular physics, plasma physics, quantum electronics, biology, etc.
The technical possibilities of photography with time resolution significantly better than 10-12 s have virtually been exhausted. The further advance into the femtosecond region requires overcoming some principal physical constraints.
This proposal concerns the study of standard photocathode (silver-oxygen-cesium), multialkaline) parameters, which influences the time resolution of the photoelectron devices. These are: velocity distribution of photoelectrons at a photocathode-vacuum boundary in presence of a strong electric field, electric strength of photoemission layers in steady and impulsive electric fields, influence of intense electric field on the photoeffect threshold.
The earlier studies of photocathode parameters have been carried out by the braking potential method at electrical field intensity of 30 V/mm; at the same time electrical field intensity near a photocathode reaches 3 kV/mm in the real time-analyzing systems.
We propose to develop special vacuum devices, where photoelectrons first are accelerated by 3 kV/mm electric field, acquire parameters of typical time-analyzing ICT, and then decelerated to the suitable for measurements energies.
In order to avoid photocurrent measurements errors, caused by photoemission from photocathode nonoperating parts and structural elements of vacuum devices, so called "clean technology" of a photocathode manufacturing will be used.
It is expected that the time-analyzing tube with slit sweep and time resolution of 100 femtoseconds or less will be created in the future on a basis of the proposed research project. Such ultimate parameters have not yet been reached in the world.