arXiv subjects

Ian Shipsey

Publications and source records attributed to Ian Shipsey.

14 recordsLinked to original sources

arXiv2025

Bounds on heavy axions with an X-ray free electron laser

We present new exclusion bounds obtained at the European X-ray Free Electron Laser facility (EuXFEL) on axion-like particles (ALPs) in the mass range 10^{-3} eV < m_a < 10^4 eV. Our experiment exploits the Primakoff effect via which photons can, in the presence of a strong external electric field, decay into axions, which then convert back into photons after passing through an opaque wall. While similar searches have been performed previously at a 3^rd generation synchrotron, our work demonstrates improved sensitivity, exploiting the higher brightness of X-rays at EuXFEL.

hep-ph↗

arXiv2024

Dose rate dependence of TID damage to 65 nm CMOS transistors in X-ray irradiations of the ATLAS ITk Pixel ASIC (ITkPix)

The ATLAS Inner Tracker (ITk) upgrade for the High-Luminosity LHC (HL-LHC) requires a radiation-tolerant pixel readout chip, which must withstand a total ionising dose (TID) of up to 1 Grad. The readout ASIC for the ITk upgrade has been designed by the RD53 collaboration using 65 nm CMOS technology. In order to characterise the radiation tolerance of the chip digital logic, the RD53 ASICs include ring oscillators, which can be used to measure gate delay degradation. Extensive X-ray irradiation studies of the ring oscillators have been performed on the ITk Pixel pre-production readout ASIC, ITkPixV1. A dependence of radiation damage on dose rate has been observed in 65 nm CMOS technology. This paper aims to quantify the dose rate dependence of TID damage to the ITkPix ring oscillators and, therefore, the ITkPix ASIC digital logic. X-ray irradiations at different dose rates between 20 krad/h and 30 Mrad/h are compared. A dose rate dependence is observed, with 2-3 times more damage at the lowest dose rate of 20 krad/h, compared to 4 Mrad/h. The dose rate dependence was also observed to be dependent on transistor size and type.

physics.ins-det↗

arXiv2022

Report of the Instrumentation Frontier Working Group for Snowmass 2021

Detector instrumentation is at the heart of scientific discoveries. Cutting edge technologies enable US particle physics to play a leading role worldwide. This report summarizes the current status of instrumentation for High Energy Physics (HEP), the challenges and needs of future experiments and indicates high priority research areas. The Snowmass Instrumentation Frontier studies detector technologies and Research and Development (R&D) needed for future experiments in collider physics, neutrino physics, rare and precision physics and at the cosmic frontier. It is divided into more or less diagonal areas with some overlap among a few of them. We lay out five high-level key messages that are geared towards ensuring the health and competitiveness of the US detector instrumentation community, and thus the entire particle physics landscape.

hep-ex↗

arXiv2021

Matter-wave Atomic Gradiometer Interferometric Sensor (MAGIS-100)

MAGIS-100 is a next-generation quantum sensor under construction at Fermilab that aims to explore fundamental physics with atom interferometry over a 100-meter baseline. This novel detector will search for ultralight dark matter, test quantum mechanics in new regimes, and serve as a technology pathfinder for future gravitational wave detectors in a previously unexplored frequency band. It combines techniques demonstrated in state-of-the-art 10-meter-scale atom interferometers with the latest technological advances of the world's best atomic clocks. MAGIS-100 will provide a development platform for a future kilometer-scale detector that would be sufficiently sensitive to detect gravitational waves from known sources. Here we present the science case for the MAGIS concept, review the operating principles of the detector, describe the instrument design, and study the detector systematics.

physics.atom-ph↗

arXiv2019

Measurement of the relative response of TowerJazz Mini-MALTA CMOS prototypes at Diamond Light Source

This paper outlines the results of investigations into the effects of radiation damage in the mini-MALTA prototype. Measurements were carried out at Diamond Light Source using a micro-focus X-ray beam, which scanned across the surface of the device in 2 $\mathrm{μm}$ steps. This allowed the in-pixel photon response to be measured directly with high statistics. Three pixel design variations were considered: one with the standard continuous $\mathrm{n^-}$ layer layout and front-end, and extra deep p-well and $\mathrm{n^-}$ gap designs with a modified front-end. Five chips were measured: one unirradiated, one neutron irradiated, and three proton irradiated.

physics.ins-det↗

arXiv2019

Automatic Selection of CDS Timing Parameters

CDS is a process used in many CCD readout systems to cancel the reset noise component that would otherwise dominate. CDS processing typically consists of subtracting the integrated video signal during a "signal" period from that during a "reset" period. The response of this processing depends therefore on the shape of the video signal with respect to the integration bounds. In particular, the amount of noise appearing in the final image and the linearity of the pixel value with signal charge are affected by the choice of the CDS timing intervals. In this paper, we use a digital CDS readout system which highly oversamples the video signal (as compared with the pixel rate) to reconstruct pixel values for different CDS timings using identical raw video signal data. We use this technique to develop insights into optimal strategy for selecting CDS timings both in the digital case (where the raw video signal may be available), and in the general case where it is not. In particular, we show that the linearity of the CDS operation allows subtraction of the raw video signals of pixels in bias images from those in illuminated images to directly show the effects of CDS processing on the final (subtracted) pixel values.

astro-ph.IM↗

arXiv2018

Quantum Sensing for High Energy Physics

Report of the first workshop to identify approaches and techniques in the domain of quantum sensing that can be utilized by future High Energy Physics applications to further the scientific goals of High Energy Physics.

hep-ex↗

arXiv2017

An Electro - Optical Test System for Optimising Operating Conditions of CCD sensors for LSST

We describe the commissioning of a system which has been built to investigate optimal operation of CCDs for the LSST telescope. The test system is designed for low vibration, high stability operation and is capable of illuminating a detector in flat-field, projected spot, projected pattern and Fe-55 configurations. We compare and describe some considerations when choosing a gain calibration method for CCDs which exhibit the brighter-fatter effect. An optimisation study on a prototype device of gain and full well with varying back substrate bias and gate clock levels is presented.

astro-ph.IM↗

arXiv2017

Vision and Outlook: The Future of Particle Physics

As a community, our goal is to understand the fundamental nature of energy, matter, space, and time, and to apply that knowledge to understand the birth, evolution and fate of the universe. Our scope is broad and we use many tools: accelerator, non-accelerator & cosmological observations, all have a critical role to play. The progress we have made towards our goal, the tools we need to progress further, the opportunities we have for achieving transformational paradigm-altering scientific advances: great discoveries, and the importance of being a united global field to make progress toward our goal are the topics of this talk.

hep-ex↗

arXiv2015

Curvature Wavefront Sensing for the Large Synoptic Survey Telescope

The Large Synoptic Survey Telescope (LSST) will use an active optics system (AOS) to maintain alignment and surface figure on its three large mirrors. Corrective actions fed to the LSST AOS are determined from information derived from 4 curvature wavefront sensors located at the corners of the focal plane. Each wavefront sensor is a split detector such that the halves are 1mm on either side of focus. In this paper we describe the extensions to published curvature wavefront sensing algorithms needed to address challenges presented by the LSST, namely the large central obscuration, the fast f/1.23 beam, off-axis pupil distortions, and vignetting at the sensor locations. We also describe corrections needed for the split sensors and the effects from the angular separation of different stars providing the intra- and extra-focal images. Lastly, we present simulations that demonstrate convergence, linearity, and negligible noise when compared to atmospheric effects when the algorithm extensions are applied to the LSST optical system. The algorithm extensions reported here are generic and can easily be adapted to other wide-field optical systems including similar telescopes with large central obscuration and off-axis curvature sensing.

astro-ph.IM↗

arXiv2015

Exclusive $D_s$ semileptonic branching fraction measurements

We measure absolute branching fractions for six exclusive $D_s$ semileptonic decays. We use data collected in the CLEO-c detector from $e^+e^-$ annihilations delivered by the Cornell Electron Storage Ring with a center-of-mass energy near 4170 MeV. We find $\mathcal{B}(D_s \to ϕe ν)~= (2.14 \pm 0.17 \pm 0.09)$%, $\mathcal{B}(D_s \to ηe ν)~= (2.28 \pm 0.14 \pm 0.20)$%, and $\mathcal{B}(D_s \to η' e ν)~= (0.68 \pm 0.15 \pm 0.06)$% for the largest modes, where the first uncertainties are statistical and the second are systematic. We also obtain $\mathcal{B}(D_s \to K^0 e ν)~= (0.39 \pm 0.08 \pm 0.03)$%, $\mathcal{B}(D_s \to K^* e ν)~= (0.18 \pm 0.04 \pm 0.01)$%, and $\mathcal{B}(D_s \to f_0 e ν, f_0 \to ππ)~= (0.13 \pm 0.02 \pm 0.01)$% for $f_0$ masses within 60 MeV of 980 MeV. We use our results to determine the $η-η'$ and $f_0$ mixing angles with $s\bar{s}$, and we combine our results with lattice calculations to estimate $|V_{cs}|$. This measurement improves upon the $D_s$ semileptonic branching ratio precision and provides a new approach for future work that eliminates the $D_s^*$ daughter photon reconstruction.

hep-ex↗

arXiv2003

$D^0-\bar{D^0}$ Mixing and Rare Charm Decays

We review the current status of flavor-changing neutral currents in the charm sector. We focus on the standard-model predictions and identify the main sources of theoretical uncertainties in both charm mixing and rare charm decays. The potential of these observables for constraining short-distance physics in the standard model and its extensions is compromised by the presence of large nonperturbative effects. We examine the possible discovery windows in which short-distance physics can be tested and study the effects of various extensions of the standard model. The current experimental situation and future prospects are reviewed.

hep-ph↗

arXiv2002

CLEO-c and CESR-c: Allowing Quark Flavor Physics to Reach its Full Potential

We report on the physics potential of a proposed conversion of the CESR machine and the CLEO detector to a charm and QCD factory: ``CLEO-c and CESR-c'' that will make crucial contributions to quark flavor physics this decade, and may offer our best hope for mastering non-perturbative QCD, which is essential if we are to understand strongly coupled sectors in the new physics that lies beyond the Standard Model.

hep-ex↗

arXiv2002

Precision Determination of V_ub at an e+ e- B Factory

Current methods of determining V_ub are dominated by theoretical uncertainties. We present Monte Carlo simulations of three promising methods of determining V_ub with small theoretical and experimental errors. We find that with data samples of order 1,000 fb-1 the B factories will attain combined experimental errors of a few % on V_ub, much smaller than the theoretical errors associated with new inclusive methods. Lattice QCD offers the promise of rate calculations of exclusive semileptonic decays with errors of a few %. A data sample of order 10,000 fb-1, beyond the capabilities of the current B factories, may be required to achieve an experimental error on the exclusive rate comparable to the theoretical error.

hep-ex↗