Thermal Emission of Strontium in a Cryogenic Buffer Gas Beam Source

We demonstrate production of cold atomic strontium (Sr) and strontium-containing molecules (SrOH) in a cryogenic buffer gas beam source via direct heating of strontium oxide (SrO) with 30 mJ laser pulses several milliseconds long. 3.7(2)×10¹⁴ Sr atoms are released, which represents a factor of 7 increase in atomic production per pulse compared to nanosecond-scale ablation laser pulses. A peak atomic density of 1.93(6) × 10¹² atoms/cm³ is achieved, which corresponds to a factor of 2 increase relative to ablation. We further propose methods of extending this method to other atomic and molecular species.