Gas dynamics of pulsed low energy helium beams

• Published in: Journal of low temperature physics Vol. 121; no. 5-6; pp. 351 - 356
• Main Authors: LIDKE, K. A, WILLIAMS, M. C, WYNVEEN, A, HALLEY, J. W
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Heidelberg Springer 01.12.2000
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Other topics in quantum fluids and solids; liquid and solid helium; Physics; Quantum fluids and solids; liquid and solid helium; Helium Atoms; Boltzmann equation; Rotons; Atomic beams; Particle emission; Phonons; Superfluid; Experimental study; Helium; Particule-surface interactions; Pulsed beam
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1023/a:1017537310600

We report data on pulsed atomic helium beams for use in an experiment on atomic reemission of atoms incident on a superfluid helium four sample. We used a gas dynamics code to model these pulsed low energy helium beams and found a good fit with the experimental results at low source power. The fit implies that significant collisional effects occur in these beams. Using the model for the incident pulsed beam which we obtained, we produced simulated signals from the reemitted atoms which we expect to see in the experiment in which we monitor reemission from the sample when these atomic pulses are fired at it. We find that the present experimental could detect the proposed condensate mediated transmission process but that a larger superfluid sample would give a more definitive result.