M1: Search for third generation gravitational waves detector possible implementation sites
The Virgo gravitational wave detector, installed in Pisa, operates on the principle of a laser interferometer with 3 km long arms. In 2017, the first joint observation by the LIGO (in the United States) and Virgo detectors of gravitational waves from a coalescence of neutron stars and a gamma-ray burst, followed by that of an optical signal, opened up a whole new chapter in multi-messenger astronomy. Two periods of observation by the LIGO and Virgo detectors followed from April 2019 to March 2020, and from May 2023 to November 2025 enabling the weekly detection of coalescences of compact binary systems (black holes and neutron stars). These detectors will enter a phase of modifications and improvements in order to improve their sensitivity and start a new observing run in 2028. At the same time, preparations are under way in Europe and in the US to prepare the third generation of gravitational waves detectors, known as Cosmic Explorer and Einstein Telescope. These detectors are expected to be able to detect all binary black holes and most of binary neutron stars mergers across the Universe with 105 to 106 events per year. In order to reach such a sensitivity the arm length of these interferometers will need to reach 20 to 40 kilometers. With such a length, finding a location on the earth surface is a challenge. An alternative is to locate the detector underground but the cost of the infrastructure becomes very high due to the excavation works required. In addition, these detectors should be placed in a quiet seismic environment as ground motion directly impacts their sensitivity and duty cycle.
The proposed work consists in exploring the earth surface in order to find the best possible locations for the third generation gravitational waves detectors. The main criteria to be considered in this search are the earth surface geometry (in order to minimize the excavation needs), the land use, and the seismic activity of the site (in order to achieve the best sensitivity and duty cycle). The work will consist in two parts: the first one will be to identify and exploit the appropriate data sets and the second one will be to adapt and optimize an existing software tool (in Python) which had been developed under Python for a similar use case. A good knowledge of Python is necessary.
Informations:
Expérience: Virgo/ET
Responsable de stage: Edwige Tournefier
Email: edwige.tournefier@lapp.in2p3.fr