Gas dynamic virtual nozzle for generation of microscopic droplet streams

Abstract

As shown by Gañán-Calvo and co-workers, a free liquid jet can be compressed in diameter through gas-dynamic forces exerted by a co-flowing gas, obviating the need for a solid nozzle to form a microscopic liquid jet and thereby alleviating the clogging problems that plague conventional droplet sources of small diameter. We describe in this paper a novel form of droplet beam source based on this principle. The source is miniature, robust, dependable, easily fabricated, and eminently suitable for delivery of microscopic liquid droplets, including hydrated biological samples, into vacuum for analysis using vacuum instrumentation. Monodisperse, single file droplet streams are generated by triggering the device with a piezoelectric actuator. The device is essentially immune to clogging.

Ceramic micro-injection molded nozzles for serial femtosecond crystallography sample delivery

“…16 This led to the development of flowfocusing nozzles, which rely on a coaxial focusing gas to produce the micrometer-diameter liquid jet. 17,18 Early experimental and theoretical investigations of flowfocusing were carried out by the group of Gañán-Calvo. [19][20][21][22][23] In many of their studies, flow-focusing was achieved by drawing air through a small orifice in a flat metal plate (flat-plate apparatus), and forming a jet from a capillary precisely positioned above the orifice.…”

Fluid sample injectors for x-ray free electron laser at SACLA

“…The basic structure and working principle of GDVN are found in Refs. [46][47][48]. experiments [45] .…”

Expansion-maximization-compression algorithm with spherical harmonics for single particle imaging with x-ray lasers

“…Let us consider a shell of radius q s , and that detector coordinates on this shell are given by equation (4). We note that the number of pixels on the detector N s scales with the radius q s , given the pixel spacing ∆q.…”

“…To overcome low signal-to-noise, the experiment involves a large number of diffraction measurements (10 4 -10 6 ) and each measurement must be of a new copy of the particle, which is assumed to have an identical structure. Such datasets are achievable because XFELs have high repetition rates (> 100 Hz [3]) and serial injection technology has been developed to continuously deliver fresh sample into the beam path [4,5]. A consequence of this experimental approach is that particle orientation is not measured and must be determined by analyzing the diffraction data [6].…”