Speaker
Dr
James Booth
(British Columbia Institute of Technology)
Description
Laser cooling and trapping of atoms has created a revolution in physics and technology.
For example, cold atoms are now the standard for time keeping which underpins the GPS network used for global navigation. In this talk, I will describe a research collaboration between BCIT, UBC (Kirk Madison) and NIST (Jim Fedchak - Sensor Science Division) with the goal of creating a cold atom (CA) based primary pressure standard for the high- and ultra-high vacuum regimes: A cold, trapped atom can act as a sensitive detector for a particle that passes through its collision cross-section and imparts momentum to it. The collision event is registered if the sensor atom's momentum gain is high enough to escape the trap. Thus, an ensemble of confined atoms measures the flux of particles via the observed loss rate of sensor atoms from the trap. In short, the particle flux (pressure) passing through the sensor atom volume transduces a timing signal (loss rate). The loss rate is sensitive to the type of collision and to the trap depth confining the atoms [1]. These factors afford an opportunity to study collision physics and the physics of the trap while working towards a new standard. The advantages of a CA standard include the fact the sensor relies on immutable properties of atomic matter and their interactions and that it will be a primary pressure standard, tied directly to the second, a base SI unit. This absolute standard would provide a valuable alternative to gas expansion/orifice flow transfer standards currently in use. In this talk I will review the basic ideas supporting the science and technology, along with an update on our progress. [1] D. Fagnan, J. Wang, C. Zhu, P. Djuricanin, B. G. Klappauf, J. L. Booth and K. W. Madison, Phys. Rev. A 80, 022712, 2009.
Author
Dr
James Booth
(British Columbia Institute of Technology)
Co-authors
Dr
James Fedchak
(Sensor Science Division, NIST)
Dr
Janelle Van Dongen
(University of British Columbia)
Mr
Kais Jooya
(University of British Columbia)
Prof.
Kirk Madison
(University of British Columbia)
