Abstract - A technique for creating microgravity conditions during free fall (GIZERO project) is described. GIZERO consists of a vacuum capsule released from balloon altitude (40 km) which is used to shield a payload with an experimental apparatus free falling inside. The expected residual acceleration is 10^−12 g/√Hz for about 20–25 seconds (50–60 seconds with a propelled capsule). The GIZERO facility provides opportunities for accurate experiments in gravitational physics. Among others, two experiments of our particular interest are: testing and calibration of a high sensitivity gravity gradiometer and a test of the Equivalence Principle (the gravity level can be reduced down to 10^−15 g/√Hz using cryogenic techniques). It is expected that a triaxial gravity gradiometer prepared for a future space mission can be tested at the sensitivity level of 10^−2 E/√Hz. The estimated accuracy in testing the Equivalence Principle is 5x10^−14 at the liquid nitrogen temperature of 77 K and 5x10^−15 at the liquid helium temperature of 4 K. This is the intermediate accuracy between ground-based and expected space experiments. The results of design and experimental study of a prototype of the gravity gradiometer are reported.

Gizero: New Facility for Gravitational Experiments in Free Fall

LORENZINI, ENRICO;
1997

Abstract

Abstract - A technique for creating microgravity conditions during free fall (GIZERO project) is described. GIZERO consists of a vacuum capsule released from balloon altitude (40 km) which is used to shield a payload with an experimental apparatus free falling inside. The expected residual acceleration is 10^−12 g/√Hz for about 20–25 seconds (50–60 seconds with a propelled capsule). The GIZERO facility provides opportunities for accurate experiments in gravitational physics. Among others, two experiments of our particular interest are: testing and calibration of a high sensitivity gravity gradiometer and a test of the Equivalence Principle (the gravity level can be reduced down to 10^−15 g/√Hz using cryogenic techniques). It is expected that a triaxial gravity gradiometer prepared for a future space mission can be tested at the sensitivity level of 10^−2 E/√Hz. The estimated accuracy in testing the Equivalence Principle is 5x10^−14 at the liquid nitrogen temperature of 77 K and 5x10^−15 at the liquid helium temperature of 4 K. This is the intermediate accuracy between ground-based and expected space experiments. The results of design and experimental study of a prototype of the gravity gradiometer are reported.
1997
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/152307
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