  Compact ultra-high vacuum systems are key enabling components for cold atom
technologies, facilitating extremely accurate sensing applications. There has
been important progress towards a truly portable compact vacuum system, however
size, weight and power consumption can be prohibitively large, optical access
may be limited, and active pumping is often required. Here, we present a
centilitre-scale ceramic vacuum chamber with He-impermeable viewports and an
integrated diffractive optic, enabling robust laser cooling with light from a
single polarization-maintaining fibre. A cold atom demonstrator based on the
vacuum cell delivers $10^7$ laser-cooled $^{87}$Rb atoms per second, using
minimal electrical power. With continuous Rb gas emission active pumping yields
a $10^{-7}\,$mbar equilibrium pressure, and passive pumping stabilises to
$3\times 10^{-6}\,$mbar, with a $17\,$day time constant. A passively-pumped
vacuum cell, with no Rb dispensing, has currently kept a similar pressure for a
year. The passive-pumping vacuum lifetime is several years, estimated from
short-term He throughput, with many foreseeable improvements. This technology
enables wide-ranging mobilization of ultracold quantum metrology.
