– AstroParticle Phyics

Antares/KM3NeT

Programme Leader

Paul de Jong

Main points: scientific

Antares

  • Point source searches and diffuse flux measurements with cascades and tracks (all neutrino flavors)
  • Limits on neutrino flux from galactic plane
  • Searches for neutrinos from various GW events, black-hole mergers as well as neutron star merger
  • Dark matter searches from center of the earth and from Milky Way

KM3NeT

  • In-situ calibration of the first two ARCA lines, timing calibration, determination of PMT efficiencies, and comparison to atmospheric muons MC

Main points: technical

  • Further improvements in KM3NeT design, a.o. optical system, timing calibration procedure, CLB firmware, PMT bases, penetrators.
  • Construction and tests of more than 90 DOMs, and integration of 2 ORCA DUs
  • Deployment of the first ORCA line

Key positions in collaborations

KM3NeT

  • Deputy spokesperson: Aart Heijboer
  • Technical coordinator: Els Koffeman
  • Optical systems coordinator: Gerard Kieft
  • Mechanics coordinator: Edward Berbee

ANTARES

  • Point sources group convener: Dorothea Samtleben

Main paper in 2017

  • First all-flavor neutrino pointlike source search with the ANTARES neutrino telescope, Phys. Rev. D. 96 (2017) 082001

Cosmic Rays (Pierre Auger Observatory & GRAND)

Programme Leader

Sijbrand de Jong

Main points: scientific

  • Observation of a Large-scale Anisotropy in the Arrival Directions of Cosmic Rays above 8×1018 eV
  • Search for High-Energy Neutrinos from Binary Neutron Star Merger GW170817
  • Inferences on Mass Composition and Tests of Hadronic Interactions from 0.3 to 100 EeV using the water-Cherenkov Detectors of the Pierre Auger Observatory
  • Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

Main points: technical

  • Design of AugerPrime upgrade SSD modules completed under Nikhef leadership
  • Improved arrival time variance model for the surface detector
  • First full fit model for the surface detector time trace, revealing sensitivity to composition and photon identification;
  • Start of SSD module production

Awards, fellowships etc.

  • Physics World Top Ten Breakthrough of 2017 (2x!)

Key positions in collaborations

  • Auger Eengineering Radion Array group leader: Jörg Hörandel
  • Auger outreach co-convenor: Charles Timmermans
  • GRAND technical coordinator: Charles Timmermans

Main paper in 2017

  • Observation of a Large-scale Anisotropy in the Arrival Directions of Cosmic Rays above 8×1018 eV, The Pierre Auger Collaboration, Science 357 (2017) 1266-1270

Dark Matter

Programme Leader

Patrick Decowski

Main points: scientific

  • The XENON1T has become the world’s most sensitive direct detection dark matter experiment
  • First results from the XENON1T experiment. With only 34 days of data, the experiment published some of the world’s most stringent limits on spin-independent WIMP-nucleon cross sections.
  • The experiment has accumulated more than 8x more data compared to the amount used in the first published results. Analysis of this blind data is ongoing.

Main points: technical

  • Stellar performance of the Nikhef-designed trigger and event-builder, with very little down time.
  • SURFsara/Nikhef Grid resources fully integrated in XENON data processing chain

Key positions in collaborations

  • Chair of the XENON1T Editorial Board: Patrick Decowski
  • XENONnT Technical Coordinator : Auke Pieter Colijn

Main paper in 2017

  • XENON Collaboration (E. Aprile et al.), Phys. Rev. Lett. 119, 181301 (2017). arXiv:1605.06655

Gravitational Waves

Programme Leader

Frank Linde

Main points: scientific

  • Jo van den Brand becomes spokesperson Virgo
  • Neutron star merger seen
  • Nobel Prize Grav. Wave Detection
  • Virgo made its first GW observation
  • ET/PR event in Nieuwspoort, Den Haag
  • Appointment Bas Swinkels, Matteo Tacca and Sarah Caudill

Main points: technical

  • Virgo operational in August
  • Deployment + analysis passive seismic sensors in Limburg/Terziet

Key positions in collaborations

  • Spokesperson Virgo: Jo van den Brand
  • Coordinator Suspended Optical Benches subsystem: Alessandro Bertolini
  • Member LIGO-Virgo Collaboration Detection Committee: Alessandro Bertolini
  • Professorship Un. Groningen: Chris Van Den Broeck
  • Co-convenor science case for 3rd generation (GWIC committee): Chris Van Den Broeck

Main paper in 2017

  • Neutron star merger (multi messenger): Phys.Rev.Lett. 119 (2017) no.16, 161101 and Astrophys.J. 848 (2017) no.2, L12