Search

Galactic (GCR) and solar cosmic rays with energies larger than 100 MeV(/n) penetrate and charge the test masses of the LISA missions. Spurious forces between the test-masses and the surrounding electrodes might be mistaken for genuine gravitational wave signals. In this paper, we report about galactic and interplanetary cosmic rays charging the LISA test-masses as a function of the solar activity level and Global Solar Magnetic Field (GSMF) polarity. The simulation work has been carried out with the use of the Fluka Monte Carlo program (2005 release) and completes our previous results on galactic cosmic rays. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

With data analysis preparations for LISA underway, there has been renewed interest in studying solar, cosmic ray and environmental physics for, and using LISA. The motivation for these studies is two fold. The primary incentive is to predict and consequently minimize the impact of disturbances associated with these factors, to maximize LISA’s gravitational wave scientific yield. The second stimulus is the unique opportunity that is afforded by LISA’s long-baseline 3-spacecraft configuration for studies of solar, cosmic ray and environmental physics. Here we present an overview of recent progress in these studies. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

On-ground tests are required to study the couplings between LISA test masses and the spacecraft that host them. In order to study couplings that might act between two ore more degrees of freedom in measuring the position and acting on the position of each test mass, a many degrees of freedom facility is needed. Here we present the status of our new 2 DoF double torsion pendulum, that will be used to test LISA Gravitational Reference Sensor (GRS) on the ground. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

LISA PathFinder (LPF) will be flown with the objective to test in space key technologies for LISA. However its sensitivity goals are, for good reason, one order of magnitude less than those which LISA will have to meet, both in drag-free and optical metrology requirements, and in the observation frequency band. While the expected success of LPF will of course be of itself a major step forward to LISA, one might not forget that a further improvement by an order of magnitude in performance will still be needed. Clues for the last leap are to be derived from proper disentanglement of the various sources of noise which contribute to the total noise, as measured in flight during the PathFinder mission. This paper describes the principles, workings and requirements of one of the key tools to serve the above objective: the diagnostics subsystem. This consists in sets of temperature, magnetic field, and particle counter sensors, together with generators of controlled thermal and magnetic perturbations. At least during the commissioning phase, the latter will be used to identify feed-through coefficients between diagnostics sensor readings and associated actual noise contributions. A brief progress report of the current state of development of the diagnostics subsystem will be given as well. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]