Precision Velocity Measurements of Pulsed Supersonic Jets

Abstract

ARTICLEspatial extent of the electronic excitation. This achievement in kinetic energy resolution permits monitoring the minutest temperature and pressure changes in the reservoir. It thus provides one important prerequisite for precise and reliable studies of fluid-phase transitions using supersonic beams. 18,61

Stationary flow conditions in pulsed supersonic beams

“…[118][119][120][121] In short, it consists of a differentially pumped ultrahigh vacuum set-up with a customer-specific version of the Even-Lavie pulsed valve. The valve control 122 provides two complementary means for adjusting the opening behavior, namely, the maximum solenoid current, I v , and the pulse width of the valve control signal, δt 0 .…”

Probing Phase Transitions with Supersonic Beams – A Joint Experimental and Theoretical Study

“…The experimental design has been described in detail in references [41][42][43][44]. Briefly, it consists of a differentially pumped ultra-high vacuum apparatus with a pulsed jet expansion.…”

Ultra-precise particle velocities in pulsed supersonic beams

“…Increasing the number of recorded spectra it is possible to further reduce their standard deviation, matching a precision of 1 × 10 −4 , thus improving time and velocity reproducibility threefold as compared to our previous report. 61 This advance is due to a new temperature control of the thermocouple signal converter and systematic reference measurements: Timeof-flight spectra are considered sufficiently accurate only if the mean arrival times of the associated reference spectra, recorded at earlier and later times, differ by less than 150 ns.…”

“…[51][52][53][54][55][56][57][58][59][60] Here we describe a universally applicable and exceptionally accurate method to determine the complete velocity distribution of selected particles in a supersonic beam, including its mean flow velocity. It is based on an extraordinarily precise measurement of the arrival time distribution (ATD) of particles, 61 with a repeatability in the mean time-of-flight of a) Electronic mail: christen@wolfgang-christen.net t / t < 10 −4 . Commonly, such an indirect approach involving the conversion of the mean flight time of particles to the mean flow velocity introduces additional uncertainties due to errors in the determination of the flight distance between source and detector.…”