We cool our experiment to 10 K in the hope that the plasmas will also reach this temperature eventually. But the final temperature Tf of any cooled body also depends on the ratio of cooling rate Γ to heating power H:
To reach the lowest plasma temperatures, we need to minimize H and maximize Γ. We have successfully increased Γ
by over an order of magnitude by coupling the electron cyclotron motion to a microwave cavity.
The microwave cavity traps a set of electromagnetic modes, each with a characteristic frequency. When we tune the magnetic field B so that the electron cyclotron frequency eB/m matches the frequency of a cavity mode, the cavity can absorb cyclotron energy from the electrons, and the plasmas cool more quickly.
See our latest publication in Physical Review Letters on the publications page.