Anti-reflection coated vacuum window for the Primordial Inflation Polarization ExploreR (PIPER) balloon-borne instrument
dc.contributor.author | Datta, Rahul | |
dc.contributor.author | Chuss, David T. | |
dc.contributor.author | Eimer, Joseph | |
dc.contributor.author | Essinger-Hileman, Thomas | |
dc.contributor.author | Gandilo, Natalie N. | |
dc.contributor.author | Helson, Kyle | |
dc.contributor.author | Kogut, Alan J. | |
dc.contributor.author | Lowe, Luke | |
dc.contributor.author | Mirel, Paul | |
dc.contributor.author | Rostem, Karwan | |
dc.contributor.author | Sagliocca, Marco | |
dc.contributor.author | Sponseller, Danielle | |
dc.contributor.author | Switzer, Eric R. | |
dc.contributor.author | Taraschi, Peter A. | |
dc.contributor.author | Wollack, Edward J. | |
dc.date.accessioned | 2022-02-08T15:43:02Z | |
dc.date.available | 2022-02-08T15:43:02Z | |
dc.date.issued | 2021-03-12 | |
dc.description.abstract | Measuring the faint polarization signal of the cosmic microwave background (CMB) not only requires high optical throughput and instrument sensitivity but also control over systematic effects. Polarimetric cameras or receivers used in this setting often employ dielectric vacuum windows, filters, or lenses to appropriately prepare light for detection by cooled sensor arrays. These elements in the optical chain are typically designed to minimize reflective losses and hence improve sensitivity while minimizing potential imaging artifacts such as glint and ghosting. The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne instrument designed to measure the polarization of the CMB radiation at the largest angular scales and characterize astrophysical dust foregrounds. PIPER’s twin telescopes and detector systems are submerged in an open-aperture liquid helium bucket dewar. A fused-silica window anti-reflection (AR) coated with polytetrafluoroethylene is installed on the vacuum cryostat that houses the cryogenic detector arrays. Light passes from the skyward portions of the telescope to the detector arrays through this window, which utilizes an indium seal to prevent superfluid helium leaks into the vacuum cryostat volume. The AR coating implemented reduces reflections from each interface to <1% compared to ∼10% from an uncoated window surface. The AR coating procedure and room temperature optical measurements of the window are presented. The indium vacuum sealing process is also described in detail, and test results characterizing its integrity to superfluid helium leaks are provided. | en_US |
dc.description.sponsorship | R. Datta’s research was supported by an appointment to the NASA Postdoctoral Program at the NASA Goddard Space Flight Center (GSFC), administered by the Universities Space Research Association under contract with NASA. K. Helson’s research was supported by NASA under Award No. 80GSFC17M0002. PIPER was supported under Grant No. 13-APRA13-0093. Support for the development of the microwave instrumentation and metrology was provided by the GSFC Internal Research and Development (IRAD) program. The authors acknowledge the collective contributions of the anonymous reviewers, which greatly improved the clarity of the final presentation. | en_US |
dc.description.uri | https://aip.scitation.org/doi/abs/10.1063/5.0029430 | en_US |
dc.format.extent | 12 pages | en_US |
dc.genre | journal articles | en_US |
dc.identifier | doi:10.13016/m2oyoi-po72 | |
dc.identifier.uri | https://doi.org/10.1063/5.0029430 | |
dc.identifier.uri | http://hdl.handle.net/11603/24139 | |
dc.language.iso | en_US | en_US |
dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
dc.relation.ispartof | UMBC Center for Space Sciences and Technology | |
dc.relation.ispartof | UMBC Faculty Collection | |
dc.rights | This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law. | en_US |
dc.rights | Public Domain Mark 1.0 | * |
dc.rights.uri | http://creativecommons.org/publicdomain/mark/1.0/ | * |
dc.title | Anti-reflection coated vacuum window for the Primordial Inflation Polarization ExploreR (PIPER) balloon-borne instrument | en_US |
dc.type | Text | en_US |
dcterms.creator | https://orcid.org/0000-0001-9238-4918 | en_US |