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Dive into the research topics where Andrew J. May is active.

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Featured researches published by Andrew J. May.


arXiv: Instrumentation and Methods for Astrophysics | 2018

Cooldown strategies and transient thermal simulations for the Simons Observatory

Gabriele Coppi; Zhilei Xu; Aamir Ali; Nicholas Galitzki; Patricio A. Gallardo; Andrew J. May; Jack L. Orlowski-Scherer; Mark J. Devlin; Simon R. Dicker; Brian Keating; M. Limon; Marius Lungu; Jeff McMahon; Michael D. Niemack; L. Piccirillo; Giuseppe Puglisi; Maria Salatino; Sara M. Simon; Grant Teply; Robert T; Eve M. Vavagiakis; Ningfeng Zhu

The Simons Observatory (SO) will provide precision polarimetry of the cosmic microwave background (CMB) using a series of telescopes which will cover angular scales from arc-minutes to tens of degrees, contain over 60,000 detectors, and observe in frequency bands between 27 GHz and 270 GHz. SO will consist of a six-meter-aperture telescope initially coupled to roughly 35,000 detectors along with an array of half-meter aperture refractive cameras, coupled to an additional 30,000+ detectors. The large aperture telescope receiver (LATR) is coupled to the SO six-meter crossed Dragone telescope and will be 2.4 m in diameter, weigh over 3 metric tons, and have five cryogenic stages (80 K, 40 K, 4 K, 1 K and 100 mK). The LATR is coupled to the telescope via 13 independent optics tubes containing cryogenic optical elements and detectors. The cryostat will be cooled by two Cryomech PT90 (80 K) and three Cryomech PT420 (40 K and 4 K) pulse tube cryocoolers, with cooling of the 1 K and 100 mK stages by a commercial dilution refrigerator system. The secondo component, the small aperture telescope (SAT), is a single optics tube refractive cameras of 42 cm diameter. Cooling of the SAT stages will be provided by two Cryomech PT420, one of which is dedicated to the dilution refrigeration system which will cool the focal plane to 100 mK. SO will deploy a total of three SATs. In order to estimate the cool down time of the camera systems given their size and complexity, a finite difference code based on an implicit solver has been written to simulate the transient thermal behavior of both cryostats. The result from the simulations presented here predict a 35 day cool down for the LATR. The simulations suggest additional heat switches between stages would be effective in distribution cool down power and reducing the time it takes for the LATR to reach its base temperatures. The SAT is predicted to cool down in one week, which meets the SO design goals.


arXiv: Instrumentation and Methods for Astrophysics | 2018

Simons Observatory large aperture receiver simulation overview

John L. Orlowski-Scherer; Ningfeng Zhu; Xhilei Zhu; K. Arnold; Sara M. Simon; Nicholas Galitzki; Simon Dikcer; M. Limon; Mark J. Devlin; Michael D. Niemack; Giuseppe Puglisi; Gabriele Coppi; Eve M. Vavagiakis; Max Silva-Feaver; Brian Keating; Aamir Ali; L. Piccirillo; Adrian T. Lee; Patricio A. Gallardo; Maria Salatino; Peter Ashton; Jeff McMahon; Marius Lungu; Andrew J. May; Robert Thornton

The Simons Observatory (SO) will make precision temperature and polarization measurements of the cosmic microwave background (CMB) using a series of telescopes which will cover angular scales between one arcminute and tens of degrees, contain over 60,000 detectors, and sample frequencies between 27 and 270 GHz. SO will consist of a six-meter-aperture telescope coupled to over 30,000 detectors along with an array of half-meter aperture refractive cameras, which together couple to an additional 30,000+ detectors. SO will measure fundamental cosmological parameters of our universe, find high redshift clusters via the Sunyaev-Zeldovich effect, constrain properties of neutrinos, and seek signatures of dark matter through gravitational lensing. In this paper we will present results of the simulations of the SO large aperture telescope receiver (LATR). We will show details of simulations performed to ensure the structural integrity and thermal performance of our receiver, as well as will present the results of finite element analyses (FEA) of designs for the structural support system. Additionally, a full thermal model for the LATR will be described. The model will be used to ensure we meet our design requirements. Finally, we will present the results of FEA used to identify the primary vibrational modes, and planned methods for suppressing these modes. Design solutions to each of these problems that have been informed by simulation will be presented.


arXiv: Instrumentation and Methods for Astrophysics | 2018

Simons Observatory large aperture telescope receiver design overview

Ningfeng Zhu; John L. Orlowski-Scherer; Zhilei Xu; Aamir Ali; K. Arnold; Peter Ashton; Gabriele Coppi; Mark J. Devlin; Simon R. Dicker; Nicholas Galitzki; Patricio A. Gallardo; Shuay-Pwu P. Ho; J. Hubmayr; Brian Keating; Adrian T. Lee; M. Limon; Philip Daniel Mauskopf; Andrew J. May; Jeff McMahon; Michael D. Niemack; L. Piccirillo; Giuseppe Puglisi; Maria Salatino; Mayuri S. Rao; Max Silva-Feaver; Sara M. Simon; Suzanne T. Staggs; Joel N. Ullom; Eve M. Vavagiakis; B. Westbrook

The Simons Observatory (SO) will make precision temperature and polarization measurements of the cosmic microwave background (CMB) using a series of telescopes which will cover angular scales between one arcminute and tens of degrees and sample frequencies between 27 and 270 GHz. Here we present the current design of the large aperture telescope receiver (LATR), a 2.4m diameter cryostat that will be mounted on the SO 6m telescope and will be the largest CMB receiver to date. The cryostat size was chosen to take advantage of the large focal plane area having high Strehl ratios, which is inherent to the Cross-Dragone telescope design. The LATR will be able to accommodate thirteen optics tubes, each having a 36 cm diameter aperture and illuminating several thousand transition-edge sensor (TES) bolometers. This set of equipment will provide an opportunity to make measurements with unparalleled sensitivity. However, the size and complexity of the LATR also pose numerous technical challenges. In the following paper, we present the design of the LATR and include how we address these challenges. The solutions we develop in the process of designing the LATR will be informative for the general CMB community, and for future CMB experiments like CMB-S4.


Proceedings of SPIE | 2016

Sorption-cooled continuous miniature dilution refrigeration for astrophysical applications

Andrew J. May; Paolo G. Calisse; Gabriele Coppi; Vic Haynes; L. Martinis; M. McCulloch; S. J. Melhuish; L. Piccirillo

A progress report is provided on the development of a tiltable continuous miniature dilution refrigerator and associated 3He/4He sorption coolers. These systems are currently being developed to provide sub-Kelvin cooling of the bolometer arrays for several ground- and balloon-based experiments which aim to measure the polarization of the Cosmic Microwave Background (QUBIC, LSPE and POLARBEAR-2). The novel tiltable miniaturised system benefits from a lack of external circulation pumps and a mechanically simple design. The condenser of the twin-pumped recirculating diluter is cooled continuously by two 3He/4He sorption coolers. The sorption pumps are operated by convective heat switches. The dilution unit features a thermally separated mixing chamber, still and step heat exchangers. The designs and analyses of both the sorption coolers and the diluter are reported; both systems have been manufactured and are presently under test.


arXiv: Instrumentation and Methods for Astrophysics | 2018

The Simons Observatory: instrument overview

Nicholas Galitzki; Taylor Baildon; D. Barron; Jacob Lashner; Adrian T. Lee; Yaqiong Li; M. Limon; Marius Lungu; F. Matsuda; Philip Daniel Mauskopf; Andrew J. May; Nialh McCallum; Jeff McMahon; F. Nati; Michael D. Niemack; John L. Orlowski-Scherer; Stephen C. Parshley; L. Piccirillo; Mayuri S. Rao; Maria Salatino; Joseph Seibert; Carlos Sierra; Max Silva-Feaver; Sara M. Simon; Suzanne T. Staggs; Jason R. Stevens; A. Suzuki; Grant Teply; Robert Thornton; Calvin Tsai

The Simons Observatory (SO) will make precision temperature and polarization measurements of the cosmic microwave background (CMB) using a series of telescopes which will cover angular scales between 1 arcminute and tens of degrees, contain over 40,000 detectors, and sample frequencies between 27 and 270 GHz. SO will consist of a six-meter-aperture telescope coupled to over 20,000 detectors along with an array of half-meter aperture refractive cameras, coupled to an additional 20,000+ detectors. The unique combination of large and small apertures in a single CMB observatory, which will be located in the Atacama Desert at an altitude of 5190 m, will allow us to sample a wide range of angular scales over a common survey area. SO will measure fundamental cosmological parameters of our universe, find high redshift clusters via the Sunyaev-Zeldovich effect, constrain properties of neutrinos, and seek signatures of dark matter through gravitational lensing. The complex set of technical and science requirements for this experiment has led to innovative instrumentation solutions which we will discuss. The large aperture telescope will couple to a cryogenic receiver that is 2.4 m in diameter and over 2 m long, creating a number of interesting technical challenges. Concurrently, we are designing an array of half-meter-aperture cryogenic cameras which also have compelling design challenges. We will give an overview of the drivers for and designs of the SO telescopes and the cryogenic cameras that will house the cold optical components and detector arrays.


arXiv: Instrumentation and Methods for Astrophysics | 2018

Design and characterization of the POLARBEAR-2b and POLARBEAR-2c cosmic microwave background cryogenic receivers

K. Arnold; Brian Keating; Logan Howe; L. Lowry; Calvin Tsai; Gabriele Coppi; Andrew J. May; Grant Teply; N. Stebor; John Groh; Adrian T. Lee; Xiaoyu Guo; L. Piccirillo

The POLARBEAR-2/Simons Array Cosmic Microwave Background (CMB) polarization experiment is an upgrade and expansion of the existing POLARBEAR-1 (PB-1) experiment, located in the Atacama desert in Chile. Along with the CMB temperature and E-mode polarization anisotropies, PB-1 and the Simons Array study the CMB B-mode polarization anisotropies produced at large angular scales by inflationary gravitational waves, and at small angular scales by gravitational lensing. These measurements provide constraints on various cosmological and particle physics parameters, such as the tensor-to-scalar ratio r, and the sum of the neutrino masses. The Simons Array consists of three 3.5 m diameter telescopes with upgraded POLARBEAR-2 (PB-2) cryogenic receivers, named PB-2a, -2b, and -2c. PB-2a and -2b will observe the CMB over multiple bands centered at 95 GHz and 150 GHz, while PB-2c will observe at 220 GHz and 270 GHz, which will enable enhanced foreground separation and de-lensing. Each Simons Array receiver consists of two cryostats which share the same vacuum space: an optics tube containing the cold reimaging lenses and Lyot stop, infrared-blocking filters, and cryogenic half-wave plate; and a backend which contains the focal plane detector array, cold readout components, and millikelvin refrigerator. Each PB-2 focal plane array is comprised of 7,588 dual-polarization, multi-chroic, lenslet- and antenna-coupled, Transition Edge Sensor (TES) bolometers which are cooled to 250 mK and read out using Superconducting Quantum Interference Devices (SQUIDs) through a digital frequency division multiplexing scheme with a multiplexing factor of 40. In this work we describe progress towards commissioning the PB-2b and -2c receivers including cryogenic design, characterization, and performance of both the PB-2b and -2c backend cryostats.


Proceedings of SPIE | 2016

Developing a long duration 3He fridge for the LSPE-SWIPE instrument

Gabriele Coppi; Paolo de Bernardis; Andrew J. May; S. Masi; M. McCulloch; S. J. Melhuish; L. Piccirillo

A 3He sorption cooler design for the Short-Wavelength Instrument for the Polarization Explorer (SWIPE) of the Large-Scale Polarization Explorer (LSPE) balloon-borne experiment is described. The aim of this experiment is the detection of the primordial B-mode polarisation component of the Cosmic Microwave Background. The SWIPE instrument will use Transition-Edge Sensors that are designed to work at temperature of almost 300 mK. Therefore, a 3He sorption cooler has been specifically designed that can reach this temperature with a heat load of up to 25 μW. The fridge is compact in order to be housed inside the SWIPE cryostat and operate vertically. It has been designed to have a cycle duration of at least 7 days. In order to meet these specifications, the fridge will be charged with 0.75 moles of 3He.


17th International Conference on RF Superconductivity (SRF2015), Whistler, BC, Canada, Sept. 13-18, 2015 | 2015

Engineering design and prototype fabrication of HOM couplers for HL-LHC crab cavities

Carlo Zanoni; S. Belomestnykh; Shrikant Pattalwar; Jean-Marie Geisser; Federico Carra; Graeme Burt; Jean Delayen; Raphael Leuxe; Thomas Nicol; S. Atieh; Alessandro Ratti; Marco Garlaschè; Andrew J. May; Leonel Ferreira; Niklas Templeton; HyeKyoung Park; Silvia Verdú-Andrés; Zenghai Li; Ofelia Capatina; Ignacio Aviles Santillana; R. Calaga; Subashini De Silva; Thomas Jones; Qiong Wu; Teddy Capelli; Rocio Olave; Emilien Rigutto; Paula Freijedo Menendez; Binping Xiao


17th International Conference on RF Superconductivity (SRF2015), Whistler, BC, Canada, Sept. 13-18, 2015 | 2015

Design of Dressed Crab Cavities for the HL-LHC Upgrade

Carlo Zanoni; S. Belomestnykh; Shrikant Pattalwar; Federico Carra; Graeme Burt; Raphael Leuxe; Thomas Nicol; S. Atieh; Alessandro Ratti; Marco Garlaschè; Andrew J. May; Jean Delayen; Luca Dassa; Niklas Templeton; Giovanna Vandoni; HyeKyoung Park; Kiril Marinov; Silvia Verdú-Andrés; Stefanie Langeslag; Zenghai Li; Michael Guinchard; Ofelia Capatina; Ignacio Aviles Santillana; R. Calaga; Jean-Pierre Brachet; Kurt Artoos; Subashini De Silva; Gilles Favre; Thomas Jones; Qiong Wu


17th International Conference on RF Superconductivity (SRF2015), Whistler, BC, Canada, Sept. 13-18, 2015 | 2015

Design of the Thermal and Magnetic Shielding for the LHC High Luminosity Crab-Cavity Upgrade

Niklas Templeton; Alessandro Ratti; Shrikant Pattalwar; Andrew J. May; Thomas Jones; Ofelia Capatina; Teddy Capelli; Carlo Zanoni; Federico Carra; Graeme Burt; E Nolan; R. Calaga; Kiril Marinov; Raphael Leuxe; Kurt Artoos

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L. Piccirillo

University of Manchester

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Gabriele Coppi

University of Manchester

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Adrian T. Lee

Lawrence Berkeley National Laboratory

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Brian Keating

University of California

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K. Arnold

University of Wisconsin-Madison

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