Sub-100 fs streak tube: computer-aided design, manufacturing, and testing

Abstract

In the present communication we describe the design of the sub-100 fs streak-tube that may be used for commercial streak cameras manufacturing. Careful attention is paid to preparing of a very smooth input photocathode substrate on which a low surface resistance (1−5 Ohm/ ) photocathode of S-1 type is deposited. Our estimations have shown that the photocathode surface roughness of about tens of nanometers may restrict the ultimate time resolution at the level of 100 fs. This is the reason why the photocathode substrate surface has to be smooth within the units of nanometers. The curvature of the photocathode surface is also very important to compensate the difference in the time-of-flight of electrons emitted from the central and peripheral photocathode areas. Further modernization was conducted with a photocathode -accelerating mesh assembly. The assembly may operate with 2 -3 ns (FWHM) electrical pulses of 12 -15 kV amplitude. In order to improve the S/N ratio in the streaked images, a shuttering system was incorporated inside the tube. As the result, a completely new femtosecond streak tube of PV-FS-M type was designed, manufactured, and tested.

STRUCTURAL DYNAMICS OF FREE MOLECULES AND CONDENSED MATTER. Part I. THEORY AND EXPERIMENTAL TECHNIQUE

“…The development of appropriate experimental facilities for time-resolved electron diffraction and electron microscopy [144] made it possible to combine a spatial resolution on the order of ~ 10 -2 -10 -3 А with pico-and even subpicosecond temporal resolution into a single complex. Some authors have reported the generation of ~ 200-fs electron pulses [145][146][147][148][149][150][151]. The preparation of 10 fs long pulses containing 10 4 -10 6 electrons in future research would be of paramount importance for the observation of fast processes in matter and concomitant changes in its structure.…”