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Simons Observatory Large Aperture Telescope Receiver Design Overview SPIE Austin, June 2018, Paper 10708-79 Ningfeng Zhu a , John Orlowski-Scherer a , and Zhilei Xu a et al. for the Simons Observatory Collaboration a University of Pennsylvania Optics Tube The Simons Observatory (SO) will include a 6 m Cross-Dragone large aperture telescope (LAT) coupled to the large aperture telescope receiver (LATR), which will be the largest CMB receiver to date. The LAT is designed to have a large field of view capable of supporting a cryostat with up to 19 optics tubes having an aperture of 35 cm. To reduce the development risk of a 3+ meter cryostat, the LATR is being designed to accommodate 13 optics tubes. During the initial deployment, we plan to deploy seven optics tubes with three detector wafers in each, for a total of approximately 35,000 detectors (primarily at 90/150 GHz). It should be noted that each optics tube could be upgraded to support about ~50% more detectors. With this upgrade and the deployment of 19 optics tubes, the LAT could field approximately 145,000 detectors at 90/150 GHz. In this paper, we present the current design of the LATR. Manufacture of this exciting, yet challenging, instrument is expected to commence this calendar year. Acknowledgement Telescope LATR Design Overview Cross-section showing how the LATR couples to the SO 6-m telescope. In the orientation shown, light enters the telescope from the top, reflects off of the 6 m primary (M1) and 6 m secondary (M2) mirrors, and is then directed to the LATR receiver. A separate mechanism is used to rotate the receiver about its long axis as the telescope elevation structure, which is independent, rotates M1 and M2. The LATR team and the SO collaboration would like to thank the CCAT-prime team and Vertex group for working closely with us to develop the telescope design. Meyer Tool, Dynavac, PVeng, and Fermilab have provided a number of helpful suggestions regarding the cryostat design and fabrication process. This work was supported in part by a grant from the Simons Foundation (Award #457687, B.K.). Introduction Cross-section showing the major components of the LATR. In the orientation shown, light from the telescope enters from the left, passes through a 300 K window and filter stack, an 80 K filter stack, and a 40 K filter stack before being directed to an optics tube (right panel), which houses additional filters, three reimaging silicon lenses, and the detector array package (see Dicker et al., poster 10700-122, for details on optics design, and see Healy et al., poster 10708-126, for details on the detector array package). Detectors Cross-section showing the internal structure of an optics tube and the projected light path between the 4 K lens and the 100 mK focal plane array. The LATR bolometers are coupled to either feedhorns or lenslets. To maximize the sensitivity of the detector arrays and achieve photon-limited noise over all optical frequency bands, we cool down the array modules to ~100 mK. To achieve our science goals, our transition edge sensor bolometers are split into three categories: LF (27 GHz & 39 GHz), MF (93 GHz & 145 GHz), and UHF (225 GHz & 280 GHz), with each optics tube housing one dichroic pair for ease of filter and lens optimization. lenslet + sinuous antenna feedhorn + orthomode transducer Visit our website: https://simonsobser vatory.org/ For more details on detector fabrication, see Duff et al., poster 10708-76. Send correspondence to Ningfeng Zhu E-mail: [email protected] Contact Information
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Simons Observatory Large Aperture Telescope Receiver Design OverviewSPIE Austin, June 2018, Paper 10708-79
Ningfeng Zhua, John Orlowski-Scherera, and Zhilei Xua et al. for the Simons Observatory Collaboration aUniversity of Pennsylvania
Optics TubeThe Simons Observatory (SO) will include a 6 m Cross-Dragone large aperture telescope (LAT) coupled to the large aperture telescope receiver (LATR), which will be the largest CMB receiver to date. The LAT is designed to have a large field of view capable of supporting a cryostat with up to 19 optics tubes having an aperture of 35 cm. To reduce the development risk of a 3+ meter cryostat, the LATR is being designed to accommodate 13 optics tubes. During the initial deployment, we plan to deploy seven optics tubes with three detector wafers in each, for a total of approximately 35,000 detectors (primarily at 90/150 GHz). It should be noted that each optics tube could be upgraded to support about ~50% more detectors. With this upgrade and the deployment of 19 optics tubes, the LAT could field approximately 145,000 detectors at 90/150 GHz. In this paper, we present the current design of the LATR. Manufacture of this exciting, yet challenging, instrument is expected to commence this calendar year.
AcknowledgementTelescope
LATR Design Overview
Cross-section showing how the LATR couples to the SO 6-m telescope. In the orientation shown, light enters the telescope from the top, reflects off of the 6 m primary (M1) and 6 m secondary (M2) mirrors, and is then directed to the LATR receiver. A separate mechanism is used to rotate the receiver about its long axis as the telescope elevation structure, which is independent, rotates M1 and M2.
The LATR team and the SO collaboration would like to thank the CCAT-prime team and Vertex group for working closely with us to develop the telescope design. Meyer Tool, Dynavac, PVeng, and Fermilab have provided a number of helpful suggestions regarding the cryostat design and fabrication process.
This work was supported in part by a grant from the Simons Foundation (Award #457687, B.K.).
Introduction
Cross-section showing the major components of the LATR. In the orientation shown, light from the telescope enters from the left, passes through a 300 K window and filter stack, an 80 K filter stack, and a 40 K filter stack before being directed to an optics tube (right panel), which houses additional filters, three reimaging silicon lenses, and the detector array package (see Dicker et al., poster 10700-122, for details on optics design, and see Healy et al., poster 10708-126, for details on the detector array package).
Detectors
Cross-section showing the internal structure of an optics tube and the projected light path between the 4 K lens and the 100 mK focal plane array.
The LATR bolometers are coupled to either feedhorns or lenslets. To maximize the sensitivity of the detector arrays and achieve photon-limited noise over all optical frequency bands, we cool down the array modules to ~100 mK. To achieve our science goals, our transition edge sensor bolometers are split into three categories: LF (27 GHz & 39 GHz), MF (93 GHz & 145 GHz), and UHF (225 GHz & 280 GHz), with each optics tube housing one dichroic pair for ease of filter and lens optimization.
lenslet + sinuous antenna feedhorn + orthomode transducer
Visit our website: https://simonsobservatory.org/
For more details on detector fabrication, see Duff et al., poster 10708-76.
Send correspondence to Ningfeng ZhuE-mail: [email protected]
Contact Information
