SearcharxivSearch

arXiv · 1910.00955

An arm length stabilization system for KAGRA and future gravitational-wave detectors

Abstract

Modern ground-based gravitational wave (GW) detectors require a complex interferometer configuration with multiple coupled optical cavities. Since achieving the resonances of the arm cavities is the most challenging among the lock acquisition processes, the scheme called arm length stabilization (ALS) had been employed for lock acquisition of the arm cavities. We designed a new type of the ALS, which is compatible with the interferometers having long arms like the next generation GW detectors. The features of the new ALS are that the control configuration is simpler than those of previous ones and that it is not necessary to lay optical fibers for the ALS along the kilometer-long arms of the detector. Along with simulations of its noise performance, an experimental test of the new ALS was performed utilizing a single arm cavity of KAGRA. This paper presents the first results of the test where we demonstrated that lock acquisition of the arm cavity was achieved using the new ALS and residual noise was measured to be $8.2\,\mathrm{Hz}$ in units of frequency, which is smaller than the linewidth of the arm cavity and thus low enough to lock the full interferometer of KAGRA in a repeatable and reliable manner.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

T. Akutsu, M. Ando, K. Arai, Y. Arai, S. Araki, A. Araya, N. Aritomi, Y. Aso, S. Bae, Y. Bae, L. Baiotti, R. Bajpai, M. A. Barton, K. Cannon, E. Capocasa, M. Chan, C. Chen, K. Chen, Y. Chen, H. Chu, Y-K. Chu, K. Doi, S. Eguchi, Y. Enomoto, R. Flaminio, Y. Fujii, M. Fukunaga, M. Fukushima, G. Ge, A. Hagiwara, S. Haino, K. Hasegawa, H. Hayakawa, K. Hayama, Y. Himemoto, Y. Hiranuma, N. Hirata, E. Hirose, Z. Hong, B. H. Hsieh, G-Z. Huang, P. Huang, Y. Huang, B. Ikenoue, S. Imam, K. Inayoshi, Y. Inoue, K. Ioka, Y. Itoh, K. Izumi, K. Jung, P. Jung, T. Kajita, M. Kamiizumi, S. Kanbara, N. Kanda, G. Kang, K. Kawaguchi, N. Kawai, T. Kawasaki, C. Kim, J. C. Kim, W. S. Kim, Y. -M. Kim, N. Kimura, N. Kita, H. Kitazawa, Y. Kojima, K. Kokeyama, K. Komori, A. K. H. Kong, K. Kotake, C. Kozakai, R. Kozu, R. Kumar, J. Kume, C. Kuo, H-S. Kuo, S. Kuroyanagi, K. Kusayanagi, K. Kwak, H. K. Lee, H. W. Lee, R. Lee, M. Leonardi, L. C. -C. Lin, C-Y. Lin, F-L. Lin, G. C. Liu, L. -W. Luo, M. Marchio, Y. Michimura, N. Mio, O. Miyakawa, A. Miyamoto, Y. Miyazaki, K. Miyo, S. Miyoki, S. Morisaki, Y. Moriwaki. 2019-11-28. An arm length stabilization system for KAGRA and future gravitational-wave detectors. https://doi.org/10.1088/1361-6382%2Fab5c95

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

High-Speed Semi-FE Readout Module for ATLAS MDT at HL-LHC: Design and Production-Level Characterization

The High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) introduces increased demands on the ATLAS Muon Spectrometer, particularly in terms of data throughput, timing distribution and system reliability. The Phase-II Chamber Service Module (CSM) is a key component of the upgraded Monitored Drift Tube (MDT) trigger and readout system, providing a high-speed interface between the front-end electronics and the backend systems. This paper describes the design and implementation of the Phase-II CSM, together with its validation. The results show that the CSM supports two independent optical uplinks, each operating at a line rate of 10.24 Gbps, together with clock distribution and slow control in the expected operating environment. Integration with small-diameter MDT (sMDT) chambers and tests with the prototype L0MDT trigger system are also presented. The CSM boards are now in production and will be used for installation and integration during the upcoming LHC Long Shutdown.

physics.ins-det

Spectral Discrimination of Deposited Gamma-Ray Energies in a Simulated CeBr$_3$ Scintillator

We show that wavelength measurements of individual detected optical photons may provide additional information about gamma-ray energy deposited in a CeBr$_3$ crystal when the detected-photon-count distributions overlap for nearby gamma-ray energies. Monoenergetic 662 and 629 keV gammas are used in a Geant4 simulation of a $25\times25\times20~\mathrm{mm^3}$ CeBr$_3$ crystal. Assuming a light yield of $6.0\times10^4$ photons/MeV, a wavelength-independent photon-detection efficiency of 30%, and a wavelength resolution of $\sigma_{\lambda}=40$ nm, we find that the fraction of photons reconstructed above 385 nm gives an event-level separation of $\sim$ 2 standard deviations between the 662 and 629 keV event populations selected within the same $\sim$ 1%-wide detected-photon-count interval. No timing or reconstructed interaction-position information is used. The result demonstrates, within the present simulation model, that event-dependent optical spectra can retain energy information beyond an undifferentiated photon count.

physics.ins-det

Operation of a negative ion gas time projection chamber without electronegative fill gases

The high fidelity reconstruction of particle tracks in micropatterned gaseous time projection chambers renders this technology ideal for future rare-event searches, including direction-sensitive dark matter experiments. Large drift distances are typically required for such experiments, so that the overall spatial resolution is limited by diffusion. Negative ion drift exhibits lower diffusion than electron drift and is thus an attractive option for realising a large-scale detector. The use of electronegative gases to create negative ions introduces technical challenges, most notably a reduction in gain when compared to conventional gas mixtures. In this study, we demonstrate a new method for negative ion generation via dissociative electron attachment using the conventional molecular fill gas CF$_4$. Our optical measurements of negative ion drift indicate electron attachment lengths of $<$1 mm and comparable gain to electron avalanches. The individual negative ion avalanches were also time-resolved, allowing the number of ions reaching the readout to be counted. We measure an improved energy resolution by single ion counting, relative to an integrated electron avalanche signal measured under identical gain conditions.

physics.ins-det