The ALLEGRO Gravitational Wave Observatory

探测引力波将需要具有高灵敏度的探测器，这种探测器可以在多年的观测中保持下去。需要很长的观测时间才能捕捉到引力崩塌带来的罕见而短暂的引力波爆发。路易斯安那州立大学的Allegro探测器在其最佳灵敏度下长时间运行的记录是世界上最好的；它在过去5年中有4年连续运行，是国际引力事件合作组织(IGEC)的唯一美国成员。Allegro的灵敏度将进行升级，以大致赶上IGEC其他地方正在进行的改进。Allegro将在接下来的三年里运行更长的时间，直到低温棒技术完全被LIGO项目的新干涉探测器的全时操作所掩盖。两个独特的实验将与LIGO合作进行，这两个探测器的物理距离很近。一种是利用可忽略的波传播时间来寻找爆发事件，另一种是寻找大爆炸遗留下来的随机无处不在的引力波背景。

The detection of gravitational waves will require detectors with great sensitivity that can be maintained over many years of observation. Long observing times will be needed to catch those few rare and ephemeral bursts of gravitational waves expected from a gravitational collapse.The ALLEGRO detector at Louisiana State University has the best record in the world for long time operation at its best sensitivity; it has been in continuous operation for 4 of the past 5 years, as the only U.S. member of the International Gravitational Event Collaboration (IGEC).The sensitivity of ALLEGRO will be upgraded, to roughly match the improvements underway elsewhere in the IGEC. ALLEGRO will run for extended periods of time over the next three years, until the cryogenic bar technology is fully eclipsed by full time operation of the new interferometric detectors of the LIGO project.Two unique experiments in collaboration with LIGO, enabled by the close physical proximity of the two detectors, will be performed. One is a search for burst events which uses the negligible wave travel time to good advantage, and the other is a search for a random omnipresent gravitational wave background left over from big bang.