Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1710.06634

Demonstration of the length stability requirements for ALPS II with a high finesse 9.2m cavity

Jan H. Põld·Aaron D. Spector
View original source ↗Read source document ↗Export metadata ↓

Abstract

Light-shining-through-a-wall experiments represent a new experimental approach in the search for undiscovered elementary particles not accessible with accelerator based experiments. The next generation of these experiments, such as ALPS II, require high finesse, long baseline optical cavities with fast length control. In this paper we report on a length stabilization control loop used to keep a 9.2 m cavity resonant. The finesse of this cavity was measured to be 101,300$\pm$500 for 1064 nm light. Fluctuations in the differential cavity length as seen with 1064 nm and 532 nm light were measured. Such fluctuations are of high relevance, since 532 nm light will be used to sense the length of the ALPS II regeneration cavity. Limiting noise sources and different control strategies are discussed, in order to fulfill the length stability requirements for ALPS II.

Explore related subjects

physics.ins-detphysics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jan H. Põld, Aaron D. Spector. 2019-06-24. Demonstration of the length stability requirements for ALPS II with a high finesse 9.2m cavity. https://arxiv.org/abs/1710.06634

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

KEEP EXPLORING

Related papers

arXiv2026

Kinematic Fitting of electromagnetic calorimeter data - an improved method

Kinematic fitting is widely used in particle physics experiments as a powerful tool to improve experimental resolutions, to suppress background and to provide selection criteria for the identification of specific reactions. Kinematic fitting methods, however, typically assume that the fitted quantities follow Gaussian distributions; an assumption which does not always hold. This is particularly true for energy measurements from electromagnetic calorimeters. This issue can largely be overcome by performing a transformation of the non-Gaussian variables into variables which follow a Gaussian distribution. The new adapted kinematic fitting procedure allows to better account for the non-Gaussian nature of the measured calorimeter energies, at the same time improving the accuracy and robustness of the kinematic fit. This leads to improved pull and confidence-level distributions of the kinematic fit as well as improved invariant mass distributions and signal-to-background ratios in the final event sample.

physics.ins-det↗
arXiv2026

Radiation hardness characterization of SiPM sensors for Low Earth Orbit space missions

This work presents a comprehensive radiation hardness characterization of SiPM devices for space-based applications: FBK NUV-HD-MT and NUV-HD-LowCT (1$\times$1, 3$\times$3, and 6$\times$6~mm$^2$) and Hamamatsu S14160 MPPCs with equivalent active areas. Total Ionizing Dose (TID) tests were performed at the ESA/ESTEC Co-60 facility with a level of dose up to 20~krad in silicon, while displacement damage effects were evaluated using 100~MeV protons with a fluence up to $1.12\times10^{11}$~p/cm$^2$ at the Paul Scherrer Institute. Radiation damage in SiPMs manifests through two main mechanisms: ionizing energy loss and non-ionizing energy loss (NIEL), which increases dark current and dark count rate. In this work, breakdown voltage, dark current, and quenching resistance were systematically measured as functions of accumulated dose and fluence. Gain and dark count rates were indirectly measured from the characterized electrical parameters. Both technologies exhibit remarkable stability of most of the functional parameters across all dose levels, while dark current shows predictable increases significantly more pronounced under proton irradiation due to displacement damage. Based on these results, both FBK and Hamamatsu devices are confirmed suitable for Low Earth Orbit (LEO) mission environment.

physics.ins-det↗
arXiv2026

Characterization of immersed SiPM arrays in liquid scintillator between room temperature and $-30\,^{\circ}\mathrm{C}$

Liquid scintillator detectors instrumented with distributed silicon photomultiplier (SiPM) arrays can be used in compact, topology-sensitive, and low-background experiments, but the temperature dependence of SiPMs immersed directly in the scintillation medium has not been widely characterized. We report the operation of a 125-liter linear-alkylbenzene-based liquid scintillator detector read out by 125 SiPM channels immersed in the active volume, over the range from room temperature to $-30\,^{\circ}\mathrm{C}$. The detector response was measured with cosmic-ray muons, including stopping muons followed by their Michel-electron decay. Cooling from $+15\,^{\circ}\mathrm{C}$ to $-30\,^{\circ}\mathrm{C}$ reduced the SiPM dark-count rate by a factor of 13.5, increased the single-photoelectron response by 49.1%, and increased the cosmic-ray muon light yield by 16.7%. The improved photoelectron separation and baseline stability at low temperature enabled a selection of stopping-muon events, from which the effective muon lifetime was measured to be $1959\pm132\,\mathrm{ns}$, consistent with the value expected for a hydrocarbon scintillator once $μ^{-}$ capture on carbon is taken into account.

physics.ins-det↗