In-depth analysis of LISA Pathfinder performance results: Time evolution, noise projection, physical models, and implications for LISA
Creators: name: Armano, M.
name: Audley, H.
name: Baird, J.
name: Binetruy, P.
name: Born, M.
name: Bortoluzzi, D.
name: Castelli, E.
name: Cavalleri, A.
name: Cesarini, A.
name: Chiavegato, V.
name: Cruise, A. M.
name: Bosco, D. Dal
name: Danzmann, K.
name: Silva, M. De Deus
name: Diepholz, I.
name: Dixon, G.
name: Dolesi, R.
name: Ferraioli, L.
name: Ferroni, V.
name: Fitzsimons, E. D.
name: Freschi, M.
name: Gesa, L.
name: Giardini, D.
name: Gibert, F.
name: Giusteri, R.
name: Grimani, C.
name: Grzymisch, J.
name: Harrison, I.
name: Hartig, M. S.
name: Heinzel, G.
name: Hewitson, M.
name: Hollington, D.
name: Hoyland, D.
name: Hueller, M.
name: Inchauspé, H.
name: Jennrich, O.
name: Jetzer, P.
name: Johlander, B.
name: Karnesis, N.
name: Kaune, B.
name: Korsakova, N.
name: Killow, C. J.
name: Lobo, J. A.
name: Lopez-Zaragoza, J. P.
name: Maarschalkerweerd, R.
name: Mance, D.
name: Martın, V.
name: Martin-Polo, L.
name: Martin-Porqueras, F.
name: Martino, J.
name: McNamara, P. W.
name: Mendes, J.
name: Mendes, L.
name: Meshksar, N.
name: Nofrarias, M.
name: Paczkowski, S.
name: Perreur-Lloyd, M.
name: Petiteau, A.
name: Plagnol, E.
name: Ramos-Castro, J.
name: Reiche, J.
name: Rivas, F.
name: Robertson, D. I.
name: Russano, G.
name: Sala, L.
name: Slutsky, J.
name: Sopuerta, C. F.
name: Sumner, T.
name: Texier, D.
name: Thorpe, J. I.
name: Vetrugno, D.
name: Vitale, S.
name: Wanner, G.
name: Ward, H.
name: Wass, P.
name: Weber, W. J.
name: Wissel, L.
name: Wittchen, A.
name: Zanoni, C.
name: Zweifel, P.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present an in-depth analysis of the LISA Pathfinder differential acceleration performance over the entire course of its science operations, spanning approximately 500 days. We find that: 1) the evolution of the Brownian noise that dominates the acceleration amplitude spectral density (ASD), for frequencies $f\gtrsim 1\,\text{mHz}$, is consistent with the decaying pressure due to the outgassing of a single gaseous species. 2) between $f=36\,μ\text{Hz}$ and $1\,\text{mHz}$, the acceleration ASD shows a $1/f$ tail in excess of the Brownian noise of almost constant amplitude, with $\simeq 20\%$ fluctuations over a period of a few days, with no particular time pattern over the course of the mission; 3) at the lowest considered frequency of $f=18\,μ\text{Hz}$, the ASD significantly deviates from the $1/f$ behavior, because of temperature fluctuations that appear to modulate a quasi-static pressure gradient, sustained by the asymmetries of the outgassing pattern. We also present the results of a projection of the observed acceleration noise on the potential sources for which we had either a direct correlation measurement, or a quantitative estimate from dedicated experiments. These sources account for approximately $40\%$ of the noise power in the $1/f$ tail. Finally, we analyze the possible sources of the remaining unexplained fraction, and identify the possible measures that may be taken to keep those under control in LISA.