Slashdot Mirror

← Back to Stories (view on slashdot.org)

MiniGRAIL Online

Posted by michael on from the castle-of-aaaauuuggghhhh dept.

An anonymous reader writes "MiniGRAIL - the first spherical resonant mass gravitational wave detector in the world - is now taking data!!! The MiniGRAIL (Gravitational Radiation Antenna In Leiden) detector is located at the Kamerlingh Onnes Laboratory of the Leiden University (The Netherlands). The MiniGRAIL detector is a cryogenic 68 cm diameter spherical gravitational wave antenna made of CuAl(6%) alloy with a mass of 1400 Kg, a resonance frequency of 2.9 kHz and a bandwidth around 230 Hz, possibly higher. The quantum-limited strain sensitivity dL/L would be ~4x10-21. The antenna will operate at a temperature of 20 mK. An other similar detector is being built in São Paulo, which will strongly increase the chances of detection by looking at coincidences. The sources we are aiming at are for instance, non-axisymmetric instabilities in rotating single and binary neutron stars, small black-hole or neutron-star mergers etc."

3 of 24 comments (clear)

  1. What's the frequency, Kenneth? by __aavljf5849 · · Score: 2, Interesting

    So, the gravitational waves has to have a frequency pretty close to 2.9kHz to be detected, then? Why that specific frequency? The site seems to offer no clues. Is it just random? It seems awfully high to me...

  2. Detection parameters? by david.given · · Score: 5, Interesting
    Since this thing is fundamentally a gravity wave antenna, what's the range of frequencies it can usefully detect? Is it just limited to 2.9kHz waves (plus or minus 115Hz)? What about harmonics? Could it be tuned for other frequencies or would that require a redesign?

    The reason I ask is that not only does this thing have immense cool value, similar detectors might be very handy for SETI. We know practically nothing about the gravity wave spectrum; it's perfectly possible that the reason we can't find any alien communications with radio telescopes is because everybody's communicating with gravity waves.

    So I'm eager to find out what this thing is capable of seeing.

    Incidentally, I'm getting slightly disturbed how similar modern gravity wave detectors are getting to those described in David Brin's Earth. If anyone invents a strange new form of physics for manipulating singularities called cavitronics, I for one wish to emigrate to Mars.

  3. Re:What? by Compuser · · Score: 2, Interesting

    Hate to reply to myself but my first post was before
    I RTFA'ed.
    Looks like for some frequencies they will be in the
    same ballpark of sensitivity as GEO which is nice
    since I always doubted theoretical estimates from
    GEO and LIGO as being too optimistic. If they can
    get to these sensitivities then maybe the big boys
    can get there too.
    Oh, and given what I heard about Kadel (their dewar
    maker of choice) I reiterate my doubts about He 3
    leaks. Why not Oxford? And how much does their
    setup cost to run continuously?