LISA and LISA PathFinder, the endeavour to detect low frequency GWs

This is a review about LISA and its technology demonstrator, LISA PathFinder. We first describe the conceptual problems which need to be overcome in order to set up a working interferometric detector of low frequency Gravitational Waves (GW), then summarise the solutions to them as currently conceived by the LISA mission team. This will show that some of these solutions require new technological abilities which are still under development, and which need proper test before being fully implemented. LISA PathFinder (LPF) is the the testbed for such technologies. The final part of the paper will address the ideas and concepts behind the PathFinder as well as their impact on LISA.Comment: 25 pages, 21 figures, presented at the Spanish Relativity Meeting, Mallorca September 2006. Will be published in Journal of Physics: Conference Series, IOP. To be published in Journal of Physics: Conference Series, IO

High-Energy Proton Testing of Sensitive Electronics for use on Modular Infrared Molecules and Ices Sensor (MIRMIS) Instrument

The Comet Interceptor (CI) mission is ESA\u27s first F class mission, selected in June 2019. This mission consists of three spacecraft: Spacecraft A (main spacecraft), Spacecraft B1 (supplied by the Japanese space agency JAXA), and Spacecraft B2. In this paper, we highlight the Modular Infrared Molecular and Ices Sensor (MIRMIS) instrument, which is integrated into the CI Spacecraft A\u27s scientific payload. In addition to hardware contributions from Finland (VTT Finland) and the UK (University of Oxford), the MIRMIS instrument team includes members from the University of Helsinki and NASA\u27s Goddard Space Flight Centre. MIRMIS covers the spectral range of 0.9 to ~25 μm. This paper presents the preliminary high-proton-energy radiation test results of MIRMIS’ near-infrared detector arraysensitive electronic components. Proton beam testing is performed to estimate Single Event Effects (SEE) on the PCB boards and SEE and Total Non-Ionizing Dose (TNID)/ Displacement Damage (DD) on the detectors. The tests were conducted at the Paul Scherrer Institute (PSI) Proton Irradiation Facility (PIF), Villigen, Switzerland. The levels for the tests were based on the mission requirements for the ESA Comet Interceptor mission: 3 years (at 1 AU- Segment 1) and 2 years (at 0.9 AU- Segment 2). The DD levels from the analysis were equivalent to 1e11 protons/cm2 with an energy of 50 MeV. The electronics are exposed to high-energy protons causing Single Event Effects (SEE) which may induce potentially destructive and non-destructive effects. The test items primarily included the InGaAs image sensors (SCD Cardinal640, standard and low noise), Xilinx Spartan-6 FPGAs (Field Programmable Gate Arrays), and other proximity electronics. The proton energies were varied from 50 to 200 MeV, at fluxes of 106 to 108 particles/cm2/s. No events were observed on the standard Cardinal640 sensor at target fluences between 1.00E+10 to 1.00E+11 particles/cm2. FPGAs did not show any susceptibility to TNID at fluences up to 1.00E+11 (particles/cm2)

Contenidos de isomeros trans de los acidos grasos en productos carnicos. (III) Tejido adiposo y grasa intramuscular de vacuno

Se presentan los resultados obtenidos para la determinación de ácidos grasos en una serie de muestras de tejidos subcutáneo y muscular, procedentes de canales de vacuno, por aplicación de la cromatografía en fase gaseosa, para los que se obtuvieron unos valores medios de 58.7% de ácidos saturados, 39.1 % de monoinsaturados y 2.7% de polinsaturados, en el tejido adiposo, y de 44.7% de saturados, 46.1% de monoinsaturados y 9.4% de polinsaturados, en el tejido muscular. Los contenidos de ácidos grasos trans muestran diferencias significativas entre ambos tejidos (medias del 7% de ácidos trans totales en grasa intramuscular y 10.5% en grasa de depósito). El C18: 1t presenta una distribución paralela a la del total de ácidos trans, mientras que para el C16: 1 trans se observa un comportamiento claramente diferente, ya que no se presentan estas diferencias significativas entre ambos tejidos. En cuanto a los factores estudiados que pueden influir en el contenido de isómeros trans, cabe destacar que la raza fue aquél que ofrecía más diferencias, mientras que entre los diversos orígenes (explotaciones ganaderas) y entre categorías de canal se presentaron menos diferencias en relación a los contenidos de estos isómeros. También es importante destacar que las correlaciones que se han observado entre los contenidos de ácidos trans y los totales de ácidos saturados, mono y polinsaturados presentan un signo contrario, según el tipo de tejido. Así, un aumento del % de ácidos trans va aparejado con un aumento de saturados y una disminución de polinsaturados en el tejido muscular, mientras que va aparejado con una disminución de saturados y un aumento de mono y polinsaturados en el tejido adiposo

In-flight Diagnostics in LISA Pathfinder

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.Peer Reviewe

In-flight Diagnostics in LISA Pathfinder

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.Peer Reviewe

The diagnostics subsystem on board LISA PathFinder and LISA

The Data and Diagnostics Subsystem of the LTP hardware and software are at present essentially ready for delivery. In this presentation we intend to describe the scientific and technical aspects of this subsystem, which includes thermal diagnostics, magnetic diagnostics and a Radiation Monitor, as well as the prospects for their integration within the rest of the LTP. We also sketch a few lines of progress recently opened up towards the more demanding diagnostics requirements which will be needed for LISA.Comment: 11 pages, 5 figures, pdflatex, prepared for the Proceedings of the 7th International LISA Symposium (Barcelona, Spain, 16-20 June-2008), submitted to Classical and Quantum Gravit

Contenidos de isomeros trans de los acidos grasos en productos carnicos. (III) Tejido adiposo y grasa intramuscular de vacuno

Se presentan los resultados obtenidos para la determinación de ácidos grasos en una serie de muestras de tejidos subcutáneo y muscular, procedentes de canales de vacuno, por aplicación de la cromatografía en fase gaseosa, para los que se obtuvieron unos valores medios de 58.7% de ácidos saturados, 39.1 % de monoinsaturados y 2.7% de polinsaturados, en el tejido adiposo, y de 44.7% de saturados, 46.1% de monoinsaturados y 9.4% de polinsaturados, en el tejido muscular. Los contenidos de ácidos grasos trans muestran diferencias significativas entre ambos tejidos (medias del 7% de ácidos trans totales en grasa intramuscular y 10.5% en grasa de depósito). El C18: 1t presenta una distribución paralela a la del total de ácidos trans, mientras que para el C16: 1 trans se observa un comportamiento claramente diferente, ya que no se presentan estas diferencias significativas entre ambos tejidos. En cuanto a los factores estudiados que pueden influir en el contenido de isómeros trans, cabe destacar que la raza fue aquél que ofrecía más diferencias, mientras que entre los diversos orígenes (explotaciones ganaderas) y entre categorías de canal se presentaron menos diferencias en relación a los contenidos de estos isómeros. También es importante destacar que las correlaciones que se han observado entre los contenidos de ácidos trans y los totales de ácidos saturados, mono y polinsaturados presentan un signo contrario, según el tipo de tejido. Así, un aumento del % de ácidos trans va aparejado con un aumento de saturados y una disminución de polinsaturados en el tejido muscular, mientras que va aparejado con una disminución de saturados y un aumento de mono y polinsaturados en el tejido adiposo

Contenidos de isomeros trans de los acidos grasos en productos carnicos (II). Tejidos adiposo y grasa intramuscular del cerdo

Se presentan los resultados obtenidos en la determinación de ácidos grasos trans en una serie de muestras de tejidos subcutáneo y muscular, procedentes de canales de cerdo, mediante cromatografía en fase gaseosa. Ambos tipos de grasas presentan valores similares y relativamente bajos, con un valor medio del 0.6% de 018:1 t. Se detecta una marcada influencia de la alimentación, puesta de manifiesto por las diferencias significativas obtenidas para los contenidos de C18:1 trans, en función del origen de las muestras. Igualmente, se recogen las correlaciones obtenidas entre los contenidos de C18:1 t. y los de ácidos grasos saturados, monoinsaturados y poliinsaturados, así como con el contenido graso intramuscular

Scientific goals achievable with radiation monitor measurements on board gravitational wave interferometers in space

Cosmic rays and energetic solar particles constitute one of the most important sources of noise for future gravitational wave detectors in space. Radiation monitors were designed for the LISA Pathfinder (LISA-PF) mission. Similar devices were proposed to be placed on board LISA and ASTROD. These detectors are needed to monitor the flux of energetic particles penetrating mission spacecraft and inertial sensors. However, in addition to this primary use, radiation monitors on board space interferometers will carry out the first multipoint observation of solar energetic particles (SEPs) at small and large heliolongitude intervals and at very different distances from Earth with minor normalization errors. We illustrate the scientific goals that can be achieved in solar physics and space weather studies with these detectors. A comparison with present and future missions devoted to solar physics is presented

On the role of radiation monitors on board LISA Pathfinder and future space interferometers

LISA (Laser Interferometer Space Antenna) and its precursor mission LISA Pathfinder (LISA-PF) will carry particle monitors for noise diagnostics. It was proposed to build and place radiation detectors on board the ASTROD missions as well. We present here a study of the solar energetic particle (SEP) events that the LISA-PF radiation monitors are able to detect above the galactic cosmic-ray (GCR) background predicted at the time of the mission data taking in 2015. In order to optimize the correlation between radiation monitor measurements and gravitational sensor test-mass charging, the energy threshold for particles traversing both detectors should be approximately the same. In LISA-PF, the radiation monitor particle energy cut-off was conservatively set at 75 MeV per nucleon (MeV/n) for protons and ion normal incidence, while the minimum energy of the same particles reaching the test masses is 100 MeV/n. We find that SEP events detectable on LISA-PF are characterized by peak fluxes and fluences at energies >75 MeV/n larger than about 45%, on average, with respect to those at energies >100 MeV/n. We conclude that for an accurate correlation between radiation monitor count rates and test-mass charging, it is mandatory to benefit from absolute flux measurements of both galactic and high-energy solar particles provided by experiments carrying magnetic spectrometers in space at the time of LISA-PF (PAMELA, AMS). On the other hand, the role of the radiation detectors on board LISA-PF is crucial allowing for SEP event onset and dynamics monitoring