Preparing for science run 1 of MiniGrail

A. de Waard, A. de Waard, M. Bassan, Y. Benzaim, V. Fafone, Jakob Flokstra, G. Frossati, L. Gottardi, C.T. Herbschleb, A. Karbalai-Sadegh, K.H. Kuit, H. van der Mark, Y. Minenkov, J.B.R. Oonk, G.V. Pallottino, J. Pleikies, A. Rocchi, O. Usenko, M. Visco

Research output: Contribution to journalArticleAcademicpeer-review

20 Citations (Scopus)


We report on the eighth cryogenic run of MiniGRAIL, which is planned to be the first science run. Three new capacitive transducers were mounted on the sphere, all coupled to superconducting transformers and a double-stage SQUID amplifier. All SQUID modules had a noise level between 1 and 2 μΦ0 Hz−1/2 at 4 K in separate test runs. The detector was upgraded with a complete data acquisition and data storage system, and a data analysis program for millisecond burst signals was written using a matched filter. Two cosmic-ray detectors were built and installed on the roof above MiniGRAIL as a veto for cosmic rays. A test run was done, but failed because of bad electrical isolation of the transducer electrode at low temperatures. A new cool-down is currently going on. With an already obtained sphere temperature of 65 mK and a SQUID noise of 100, the expected sensitivity should be 4 × 10−22 Hz−1/2.
Original languageUndefined
Pages (from-to)79-84
Number of pages6
JournalClassical and quantum gravity
Issue number8
Publication statusPublished - 2006


  • METIS-234890
  • IR-61503

Cite this