Calorimeter R&D for the SuperNEMO Double Beta Decay Experiment

SuperNEMO is a next-generation double beta decay experiment based on the successful tracking plus calorimetry design approach of the NEMO3 experiment currently running in the Laboratoire Souterrain de Modane (LSM). SuperNEMO can study a range of isotopes, the baseline isotopes are 82Se and possibly 150Nd. The total isotope mass will be 100-200 kg. A sensitivity to neutrinoless double beta decay half-life greater than 10e26 years can be reached which gives access to Majorana neutrino masses of 50-100 meV. One of the main challenges of the SuperNEMO R&D is the development of the calorimeter with an unprecedented energy resolution of 4% FWHM at 3 MeV (Qbb value of 82Se).Comment: Presented at 13th International Conference on Calorimetry in High Energy Physics (CALOR08), Pavia, Italy, 26-30 May 200

Measurement of geophysical effects on the large-scale gravitational-wave interferometer

Geophysical application of large free-mass laser interferometers, which had been designed merely for the detection of gravitational radiation of an astrophysical nature, are considered. Despite the suspended mass-mirrors, these interferometers can be considered as two coordinate meters even at very low frequency ([Formula: see text][Formula: see text]Hz) are rather accurate two-coordinate distance meters. In this case, the measurement of geodynamic deformations looks like a parallel product of long-term observations dictated by the task of the blind search for gravitational waves (GW) of extraterrestrial origin. Compared to conventional laser strain meters, gravitational interferometers have the advantage of an increased absolute value of the deformation signal due to the 3–4[Formula: see text]km baseline. The magnitude of the tidal variations of the baseline is 150–200[Formula: see text]microns, leading to conceive the observation of the fine structure of geodynamic disturbances. This paper presents the results of processing geophysical measurements made on a Virgo interferometer during test (technical) series of observations in 2007–2009. The specific design of mass-mirrors suspensions in the Virgo gravitational interferometer also creates a unique possibility of separating gravitational and deformation perturbations through a recording mutual angular deviations of the suspensions of its central and end mirrors. It gives a measurement of the spatial derivative of the gravity acceleration along with the geoid of the Earth. In this mode, the physics of the interferometer is considered with estimates of the achievable sensitivity in the application to the classical problem of registration of oscillations of the inner Earth's core

Evaluation of heat extraction through sapphire fibers for the GW observatory KAGRA

Currently, the Japanese gravitational wave laser interferometer KAGRA is under construction in the Kamioka mine. As one main feature, it will employ sapphire mirrors operated at a temperature of 20K to reduce the impact from thermal noise. To reduce seismic noise, the mirrors will also be suspended from multi-stage pendulums. Thus the heat load deposited in the mirrors by absorption of the circulating laser light as well as heat load from thermal radiation will need to be extracted through the last suspension stage. This stage will consist of four thin sapphire fibers with larger heads necessary to connect the fibers to both the mirror and the upper stage. In this paper, we discuss heat conductivity measurements on different fiber candidates. While all fibers had a diameter of 1.6mm, different surface treatments and approaches to attach the heads were analyzed. Our measurements show that fibers fulfilling the basic KAGRA heat conductivity requirement of $\kappa\geq$5000W/m/K at 20K are technologically feasible.Comment: 11 pages, 4 figure

Cryogenic payloads for the Einstein Telescope -- Baseline design with heat extraction, suspension thermal noise modelling and sensitivity analyses

The Einstein Telescope (ET) is a third generation gravitational wave detector that includes a room-temperature high-frequency (ET-HF) and a cryogenic low-frequency laser interferometer (ET-LF). The cryogenic ET-LF is crucial for exploiting the full scientific potential of ET. We present a new baseline design for the cryogenic payload that is thermally and mechanically consistent and compatible with the design sensitivity curve of ET. The design includes two options for the heat extraction from the marionette, based on a monocrystalline high-conductivity marionette suspension fiber and a thin-wall titanium tube filled with static He-II, respectively. Following a detailed description of the design options and the suspension thermal noise (STN) modelling, we present the sensitivity curves of the two baseline designs, discuss the influence of various design parameters on the sensitivity of ET-LF and conclude with an outlook to future R&D activities.Comment: 20 pages, Article to be published/submitted in Physical Review D - Journa

The Archimedes project: a feasibility study for weighing the vacuum energy

Archimedes is a feasibility study to a future experiment to ascertain the interaction of vacuum fluctuations with gravity. The future experiment should measure the force that the Earth's gravitational field exerts on a Casimir cavity by using a balance as the small force detector. The Archimedes experiment analyses the important parameters in view of the final measurement and experimentally explores solutions to the most critical problems