1. Michael Niemack, Cornell University for the CCAT-prime Collaboration
CCAT-Prime 6 meter aperture extreme field-of-view  sub-millimeter telescope on Cerro Chajnantor at 5600m, Chile
Michael Niemack, Cornell University
for the CCAT-prime Collaboration
CCAT-prime Director: Martha Haynes, Project Scientist: Gordon Stacey
28 February 2017
CMB-S4 Meeting, SLAC

2. CCAT-Prime Telescope & Site
6m aperture crossed-Dragone design delivers large, flat 8 degree focal plane
Can illuminate ~10 times more detectors than Stage III telescopes
Surface accuracy ~10 um at an outstanding sub-mm site with access to 350um – 3mm
Plan to start building this year
(Niemack, Applied Optics 2016)
CCAT site has better optical depth
majority of time
Median simultaneous PWV:
ALMA = 1.0 mm
Chajnantor = 0.6 mm
(Consistent with Grace et al. 2014)
Cumulative fraction
(Radford & Peterson, arXiv: )
28 February 2017
CMB-S4 Meeting, SLAC

3. CCAT-Prime Science Potential CMB-S4 platform
Multiple mm/sub-mm science goals
Galactic Ecology: tracing gas flows into cores and young stars in Milky Way and Nearby Galaxies
Galaxy Cluster Machine:
high S/N measurements of individual cluster kSZ, rSZ, dust, and foregrounds
Polarized dust foregrounds
[CII] Intensity Mapping: Measure star forming galaxies at reionization z=5-9, complement 21cm obs.
Potential CMB-S4 platform
submm galaxies
radio sources
rSZ
kSZ
(Stacey et al. 2015)
Simultaneous bands
350 m – 3 mm
(Figure from Mike Zemcov)
28 February 2017
CMB-S4 Meeting, SLAC

4. CCAT-prime: CMB-S4 Considerations
Large ~8 degree diameter FOV
Can host up to ~ 3m diameter CMB-S4 receiver with ~105 CMB detectors
Natural baffle around telescope to help control far sidelobes
Partial boresight rotation => separate ground pickup from sky
Studying monolithic mirror options with telescope vendors
2.5m diameter receiver design
(by Shawn Henderson)
CCAT-prime Engineering Design (by Steve Parshley)
28 February 2017
CMB-S4 Meeting, SLAC

5. CCAT-prime Status CCAT-prime Collaboration:
6m aperture with excellent potential for CMB-S4
Completed telescope design studies with two vendors, and internal reviews are underway
Aim to sign contract in March and start telescope build in 2017
Exploring partnerships with additional collaborators
CCAT-prime Collaboration:
Cornell, U. Cologne, U. Bonn, AUI, 10 Canadian University consortium, and other institutions in Chile, Germany, and elsewhere TBD
28 February 2017
CMB-S4 Meeting, SLAC