A buffer-gas cooled BEC of metastable $^4$He

We report the first creation of a BEC (of metastable helium, $^4$He$^*$) using buffer-gas cooling, without the use of laser cooling. $10^{11}$ $^4$He $^*$ atoms are produced via RF-discharge and magnetically trapped at an initial temperature of 400 mK in an anit-Helmholtz quadrupole field. These atoms are evaporatively cooled into the ultracold regime and transferred to a tightly confining superconducting QUIC trap with trap frequencies $\omega_{axial}$ = 2$\pi$ x 210 Hz and $\omega_{radial}$ = 2$\pi$ x 2500 Hz. Further cooling is achieved by driving transitions with resonant RF radiation. The transition temperature is reached at $\sim$ 5 $\mu$K with approximately $10^6$ atoms. The cloud is detected via phase-contrast imaging at 1083 nm, either in-situ or in time-of-flight.