GATE- Galileo Airbone Test of Equivalence

GG Home	GATE-"Galileo Airbone Test of Equivalence" A differential Galileo mass-dopping experiment to test the Equivalence Principle to 10^-13 in parbolic flight on board Airbus A300 zero-g aircraft What is GATE A differential Galileo-type mass dropping experiment named GAL was proposed at the University of Pisa in 1986 (PLA 116, 157, 1986) and completed at CERN in 1992 (PRL 69, 1722, 1992 in order to test the equivalence principle by testing the universality of free fall. The free falling mass was a disk made of two half disks of different composition; a violation of equivalence would produce an angular acceleration of the disk around its symmetry axis, which was measured with a modified Michelson interferometer. GATE -“Galileo Airborne Test of Equivalence” is a variant of that experiment to be performed in parabolic flight on-board the “Airbus A300 Zero-g” aircraft of the European Space Agency. The main advantages of GATE with respect to GAL are the longer time of free fall and the absence of weight in the final stage of unlocking. The longer time of fall makes the signal almost 500 times stronger and allows a spurious linear growth of the rotation angle to be separated out. More importnatly, unlocking at zero-g can significantly reduce spurious angular accelerations of the disk due to inevitable imperfections in the locking/unlocking mechanism which turned out to be the limiting factor in GAL [2]. A preliminary estimate indicates that GATE should be able to achieve a sensitivity of 1 part in 1013, an improvement by about 3 orders of magnitude with respect to GAL and by about 1 order of magnitude with respect to the best result obtained with a slowly rotating torsion balance. Ground tests of the read-out and of the locking/unlocking disturbances can be carried out prior to the aircraft experiment. Draft paper as of March 2004: "Galileo Airborne Test of Equivalence"-GATE, by A.M. Nobili, C.S. Unnikrishnan and Suresh D. Application to the Italian Ministry of University and Research for 2-yr co-funding of GATE as a project of national interest, March 2004 anna nobili Last edited: 2004-04-01

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GATE-"Galileo Airbone Test of Equivalence"

A differential Galileo mass-dopping experiment to test the Equivalence Principle to 10^-13 in parbolic flight on board Airbus A300 zero-g aircraft

What is GATE

A differential Galileo-type mass dropping experiment named GAL was proposed at the University of Pisa in 1986 (PLA 116, 157, 1986) and completed at CERN in 1992 (PRL 69, 1722, 1992 in order to test the equivalence principle by testing the universality of free fall. The free falling mass was a disk made of two half disks of different composition; a violation of equivalence would produce an angular acceleration of the disk around its symmetry axis, which was measured with a modified Michelson interferometer. GATE -“Galileo Airborne Test of Equivalence” is a variant of that experiment to be performed in parabolic flight on-board the “Airbus A300 Zero-g” aircraft of the European Space Agency. The main advantages of GATE with respect to GAL are the longer time of free fall and the absence of weight in the final stage of unlocking. The longer time of fall makes the signal almost 500 times stronger and allows a spurious linear growth of the rotation angle to be separated out. More importnatly, unlocking at zero-g can significantly reduce spurious angular accelerations of the disk due to inevitable imperfections in the locking/unlocking mechanism which turned out to be the limiting factor in GAL [2]. A preliminary estimate indicates that GATE should be able to achieve a sensitivity of 1 part in 1013, an improvement by about 3 orders of magnitude with respect to GAL and by about 1 order of magnitude with respect to the best result obtained with a slowly rotating torsion balance. Ground tests of the read-out and of the locking/unlocking disturbances can be carried out prior to the aircraft experiment.

Draft paper as of March 2004: "Galileo Airborne Test of Equivalence"-GATE, by A.M. Nobili, C.S. Unnikrishnan and Suresh D.

Application to the Italian Ministry of University and Research for 2-yr co-funding of GATE as a project of national interest, March 2004

anna nobili
Last edited: 2004-04-01