Scientific American - 11.2019

(Nancy Kaufman) #1

TIGHT BEAM


To ensure that KAGRA’s lasers can accurately
register the almost imperceptible distortions
of its mirrors caused by gravitational waves,
scientists must precisely control the location
and brightness of the laser beam. This
requires feeding the laser through what is
effectively a telescope (shown here) mated to
another vibration isolation device and
housed inside a vacuum vessel.

KEEPING COOL


A technician checks a mirror’s suspension
system before its installation inside
KAGRA’s cryogenic containers. Once inside,
the mirror and its mounting are cooled to
almost absolute zero—all in an effort to
minimize the thermal vibrations of their
constituent atoms, allowing signatures of
fainter gravitational waves to be seen.

OPPOSITE PAGE: ENRICO SACCHETTI; THIS PAGE: ROHAN MEHRA


© 2019 Scientific American
Free download pdf