Hanford 2-km Detector Retired

The most recent edition of "Listening to the Stars," the e-newsletter issued by the LIGO Hanford Observatory, contains this savory tidbit about the two-kilometer detector in Washington. This smaller cousin to Hanford's four-kilometer detector was nobly retired after a decade of continuous service in Initial LIGO. Get the details below...

"A milestone of sorts occurred at the LIGO Hanford Observatory on May 28 as the two-kilometer interferometer (H2) was operated for the final time in its existing configuration. As reported in our last edition, LIGO's sixth science run (S6) will begin in July 2009. LIGO data collection in S6 will occur on the four-kilometer detectors in Hanford and Louisiana (H1 and L1). The heightened sensitivities of these Enhanced LIGO machines will put them far enough ahead of H2 that the shorter detector will be removed from service. H2 will return in Advanced LIGO as a completely upgraded instrument with four-kilometer arms, rejoining H1 and L1 to provide LIGO with three full-length detectors fully outfitted with new mirrors, mirror suspensions, 180-watt lasers, multi-stage active vibration isolation and advanced signal processing. H2's retirement brings the era of Initial LIGO lasers to a full close as the laser systems in H1 and L1 already have been replaced for the Enhanced LIGO configuration. The H2 10-watt laser ran essentially continuously for more than 10 years, producing 1-micron light at a frequency stability of 1 part in 1010."

Read the entire recent edition of LIGO Hanford's "Listening to the Stars."