Joy Didier
A5073084387- Radio Astronomy Observations and Technology
- Superconducting and THz Device Technology
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Scientific Research and Discoveries
- Geophysics and Gravity Measurements
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Inertial Sensor and Navigation
- Planetary Science and Exploration
- Adaptive optics and wavefront sensing
- Spacecraft and Cryogenic Technologies
- Astronomy and Astrophysical Research
- Spacecraft Design and Technology
- Advanced Thermodynamic Systems and Engines
- Ionosphere and magnetosphere dynamics
- Experimental and Theoretical Physics Studies
- Aerospace Engineering and Energy Systems
- Soil Moisture and Remote Sensing
- Galaxies: Formation, Evolution, Phenomena
- GNSS positioning and interference
- Satellite Communication Systems
Columbia University
2010-2019
University of Southern California
2018-2019
Princeton University
2018
The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations the early 2020s. We describe scientific goals of experiment, motivate design, and forecast its performance. SO will measure temperature polarization anisotropy six frequency bands: 27, 39, 93, 145, 225 280 GHz. initial configuration have three small-aperture 0.5-m telescopes (SATs) one large-aperture 6-m telescope (LAT), with total 60,000 cryogenic...
The Probe of Inflation and Cosmic Origins (PICO) is a proposed probe-scale space mission consisting an imaging polarimeter operating in frequency bands between 20 800 GHz. We describe the science achievable by PICO, which has sensitivity equivalent to more than 3300 Planck missions, technical implementation, schedule cost.
EBEX is a NASA-funded balloon-borne experiment designed to measure the polarization of cosmic microwave background (CMB). Observations will be made using 1432 transition edge sensor (TES) bolometric detectors read out with frequency multiplexed SQuIDs. observe in three bands centered at 150, 250, and 410 GHz, 768, 384, 280 each band, respectively. This broad coverage provide valuable information about polarized foreground signals from dust. The sky modulated an achromatic half wave plate...
The Probe of Inflation and Cosmic Origins (PICO) is an imaging polarimeter that will scan the sky for 5 years in 21 frequency bands spread between 799 GHz. It produce full-sky surveys intensity polarization with a final combined-map noise level 0.87 $\mu$K arcmin required specifications, equivalent to 3300 Planck missions, our current best-estimate would have 0.61 (6400 missions). PICO either determine energy scale inflation by detecting tensor scalar ratio at $r=5\times 10^{-4}~(5\sigma)$,...
The E and B Experiment (EBEX) was a long-duration balloon-borne instrument designed to measure the polarization of cosmic microwave background (CMB) radiation. EBEX first implement kilo-pixel array transition edge sensor (TES) bolometric detectors CMB experiment use digital version frequency domain multiplexing system for readout TES array. scan strategy relied on 40 s peak-to-peak constant velocity azimuthal scans. We discuss unique demands design operation payload that resulted from these...
The E and B Experiment (EBEX) was a long-duration balloon-borne cosmic microwave background polarimeter that flew over Antarctica in 2013. We describe the experiment's optical system, receiver, polarimetric approach, report on their in-flight performance. EBEX had three frequency bands centered 150, 250, 410 GHz. To make efficient use of limited mass space we designed 115 cm$^{2}$sr high throughput system two ambient temperature mirrors four anti-reflection coated polyethylene lenses per...
Instabilities and turbulence extending to the smallest dynamical scales play important roles in deposition of energy momentum by gravity waves throughout atmosphere. However, these dynamics their effects have been impossible quantify date due lack observational guidance. Serendipitous optical images polar mesospheric clouds at ~82 km obtained star cameras aboard a cosmology experiment deployed on stratospheric balloon provide new tool, revealing instability structures spatial < 20 m. At 82...
We present the design and measured performance of superconducting magnetic bearing (SMB) that was used successfully as rotation mechanism in half-wave plate polarimeter E B Experiment (EBEX) during its North American test flight. EBEX is a NASA-supported balloon-borne experiment designed to measure polarization cosmic microwave background. In this implementation mounted rotor an SMB operating at sink temperature 4 K. demonstrate robust, remote operation on payload, with angular encoding...
We study the impact of spectral dependence linear polarization rotation induced by an achromatic half-wave plate on measurements cosmic microwave background in presence astrophysical foregrounds. focus systematic effects measurement inflationary gravitational waves uncertainties and index Galactic dust. find that for experimental configuration noise levels balloon-borne EBEX experiment, which has three frequency bands centered at 150, 250, 410 GHz, a crude dust subtraction process mitigates...
EBEX is a balloon-borne telescope designed to measure the polarization of cosmic microwave background radiation. During its eleven day science flight in Austral Summer 2012, it operated 955 spider-web transition edge sensor (TES) bolometers separated into bands at 150, 250 and 410 GHz. This first time that an array TES has been used on balloon platform conduct observations. Polarization sensitivity was provided by wire grid continuously rotating half-wave plate. The implementation bolometer...
Abstract EBEX was a long-duration balloon-borne experiment to measure the polarization of cosmic microwave background. The had three frequency bands centered at 150, 250, and 410 GHz first use kilopixel array transition edge sensor bolometers aboard balloon platform. We describe design characterization readout system. From lowest highest frequency, median measured detectors’ average thermal conductances were 39, 53, 63 pW/K, medians temperatures 0.45, 0.48, 0.47 K, normal resistances 1.9,...
The Simons Observatory (SO) will observe the temperature and polarization anisotropies of cosmic microwave background (CMB) over a wide range frequencies (27 to 270 GHz) angular scales by using both small (0.5 m) large (6 aperture telescopes. SO telescopes target degree where primordial B-mode signal is expected peak. incoming be modulated cryogenic, continuously-rotating half-wave plate (CRHWP) mitigate systematic effects arising from slowly varying noise detector pair-differencing. In this...
We present the results of a feasibility study, which examined deployment ground-based millimeter-wave polarimeter, tailored for observing cosmic microwave background (CMB), to Isi Station in Greenland. The instrument this study is based on lumped-element kinetic inductance detectors (LEKIDs) and an F/2.4 catoptric, crossed-Dragone telescope with 500 mm aperture. mounted inside receiver cooled $<\,4$ K by closed-cycle $^4$He refrigerator reduce loading detectors. Linearly polarized signals...
The E and B Experiment (EBEX) is a balloon-borne telescope designed to probe polarization signals in the CMB resulting from primordial gravitational waves, lensing, Galactic dust emission. EBEX completed an 11 day flight over Antarctica January 2013 data analysis underway. employs two star cameras achieve its real-time post-flight pointing requirements. We wrote software application called STARS operate, command, collect each of cameras, interface them with main computer. paid special...
EBEX (the E and B EXperiment) is a balloon-borne telescope designed to measure the polarisation of cosmic microwave background radiation. During two week long duration science flight over Antarctica, will operate 768, 384 280 spider-web transition edge sensor (TES) bolometers at 150, 250 410 GHz, respectively. The 10-hour engineering in June 2009 New Mexico Arizona provided first usage both large array TES Superconducting QUantum Interference Device (SQUID) based multiplexed readout...
We present the hardware and software systems implementing autonomous operation, distributed real-time monitoring, control for EBEX instrument.EBEX is a NASA-funded balloon-borne microwave polarimeter designed 14 day Antarctic flight that circumnavigates pole.To meet its science goals instrument autonomously executes several tasks in parallel: it collects attitude data maintains pointing order to adhere an observing schedule; tunes operates up 1920 TES bolometers 120 SQUID amplifiers...
We describe the cryostat and supporting electronics for EBEX experiment. is a balloon-borne polarimeter designed to measure B-mode polarization of cosmic microwave background radiation. The instrument includes 1.5 meter Gregorian-type telescope 1432 bolometric transition edge sensor detectors operating at 0.3 K. Electronics monitoring temperatures controlling refrigerators read out over CANbus. A timing system ensures data from all subsystems accurately synchronized. completed an engineering...
We discuss a systematic effect associated with measuring polarization continuously rotating half-wave plate. The was identified the data from E and B Experiment (EBEX), which balloon-borne instrument designed to measure of CMB as well that Galactic dust. show fraction larger than 10\% while less 3\% were expected instrumental polarization. give evidence excess is due detector non-linearity in presence HWP. couples intensity signals into develop map-based method remove Applying this for 150...
The E and B Experiment (EBEX) is a balloon-borne telescope designed to probe polarization signals in the cosmic microwave background. It completed an 11 day flight over Antarctica December 2012 / January 2013. EBEX requires 10 arcsecond accuracy on attitude determination for post-flight data analysis, 30 arcminute real-time control during flight. primary pointing sensors employed achieve these requirements are two redundant star cameras sets of orthogonal gyroscopes. This paper focused...
The E and B experiment (EBEX) is a balloon-borne telescope designed to measure the polarization of cosmic microwave background with 8' resolution employing gondola scanning speeds order degree per second. In January 2013, EBEX completed 11 days observations in flight over Antarctica covering $\sim$ 6000 square degrees sky. payload equipped two redundant star cameras sets three orthogonal gyroscopes reconstruct attitude. science goals require pointing be reconstructed approximately 10" map...