Title Here
Experimental Probe of Inflationary Cosmology (EPIC)
Jamie BockJPL / Caltech
U Chicago John Carlstrom Clem Pryke
U Colorado Jason Glenn
UC Davis Lloyd Knox
Dartmouth Robert Caldwell
Fermilab Scott Dodelson
IAP Ken Ganga Eric Hivon
IAS Jean-Loup Puget Nicolas Ponthieu
The EPIC ConsortiumCaltech/IPAC Charles Beichman Sunil Golwala Marc Kamionkowski Andrew Lange Tim Pearson Anthony Readhead Jonas Zmuidzinas
UC Berkeley/LBNL Adrian Lee Carl Heiles Bill Holzapfel Paul Richards Helmut Spieler Huan Tran Martin White
Cardiff Walter Gear
Carnegie Mellon Jeff Peterson
JPL Peter Day Clive Dickenson Darren Dowell Mark Dragovan Todd Gaier Krzysztof Gorski Warren Holmes Jeff Jewell Bob Kinsey Charles Lawrence Rick LeDuc Erik Leitch Steven Levin Mark Lysek Sara MacLellan Hien Nguyen Ron Ross Celeste Satter Mike Seiffert Hemali Vyas Brett Williams
UC Irvine Alex Amblard Asantha Cooray Manoj Kaplinghat
U Minnesota Shaul Hanany Tomotake Matsumura Michael Milligan
NIST Kent Irwin
UC San Diego Brian Keating Tom Renbarger
Stanford Sarah Church
Swales Aerospace Dustin Crumb
TC Technology Terry Cafferty
USC Aluizio Prata
Title HereUS Activities and Opportunities
NASA funded 3 mission studies for the Einstein “Inflation Probe” in 2003• Envisioned as $350-$500M mission, launch 2010 & every 3 years• Since 2003 there have been some programmatic changes at NASA…• Oral reports were given at NASA HQ this month• Written reports are still being drafted
Task Force For CMB Research (Weiss Committee) in 2005• Programmatic and technical roadmap to a 2018 launch for US agencies• Two mission options described• Sets mission guidelines: r = 0.01 is science goal
NRC panel to recommend first Beyond Einstein mission to NASA• First Beyond Einstein mission funding is to turn on 2008-9• CMBPOL, Con-X, LISA, JDEM (aka SNAP), and Black Hole Finder• Recommendation based on “scientific merit and technical readiness”• NRC also to recommend areas for technology funding for next 4 BE missions• Three CMBPOL study teams will organize a single presentation to NRC
MIDEX call expected in October 2007• Expected cap $220 - $260M including launch vehicle and 30 % cost reserve• Launch 2013 - 2015• International participation in MIDEX’s limited in the past (~30 %)• Unknown if NASA would change the rules for this AO... probably unlikely
Title HereTwo Mission Scenarios for CMBPOL
Gravitational-Wave BB Polarization Clear Justification for Space Mission - Large angular scales required
Modest Mission Parameters - Enough sensitivity to hit lensing limit - Angular resolution to probe ℓ = 100 - Broad frequency coverage
High-ℓ Science Lensing BB signal - How deeply can we remove lensing? - Will foregrounds limit us first? - How much more science do we get? - Do we need to go to space for this?
EE power spectrum to cosmic variance - Much will be done from the ground
T
E
B
B
Scalars
IGWs
r = 0.01
Dust
Synchr = 0.3
Cosmic Shear
Title Here
FUTUREPLANNEDACTIVE
EPIC is a Scan-Imaging Polarimeter
Scan detectors across sky to build CMB map Simple technique. Established history in CMB. Scaling to higher sensitivity → Only need better arrays Adapt this technique for precision polarimetry
Two mission concepts* Low Cost: High-TRL, low-resolution, sufficient capability Comprehensive Science: Larger aperture, new arrays
*See Weiss Committee TFCR Report: astro-ph 0604101
Planck
Boomerang
BICEP
QUaD
Polarbear
Maxipol
PAST
EBEX Spider
Title Here
Spin A
xis
(~1
rpm
)
Sun-Spacecraft Axis (~1 rph)
Op
tica
l Axi
s
Sun Earth
Moon
SE L2
45°55°
Orbit
Why Space?
- All-Sky Coverage - High Sensitivity - Systematic Error Control - Broad Frequency Coverage
Title Here
Title HereScan Strategy
Sun-Spacecraft Axis
45˚
DownlinkTo Earth
Precession(~1 rph)
55˚
1 m
inu
te3
min
ute
s1
ho
ur
Scan Coverage
Title HereScan Strategy
Sun-Spacecraft Axis
45˚
DownlinkTo Earth
Precession(~1 rph)
55˚
1 Day Maps
Spatial Coverage
Angular Uniformity
More than half the sky in a single day!
Title HereRedundant & Uniform Scan Coverage
Planck
WMAP
EPIC
N-hits (1-day) Angular Uniformity* (6-months)
*<cos 2>2 + <sin 2>2 0 1
Title Here
DeployedSunshield
Solar Panels
Liquid Helium Cryostat (450 ℓ)
Six 30 cm Telescopes
CommercialSpacecraft
Toroidal-Beam Antenna
Half-Wave Plate
Absorbing Forebaffle
2 K Refracting Optics
100 mK Focal Plane Array
3-Stage V-Groove Radiator8 m
Delta 2925H 3-m
EPIC Low Cost Mission Architecture
155 K
100 K
40 K
295 K
30/40 GHz 60 GHz 2 x 90 GHz 135 GHz200/300 GHz
Title HereLow-Cost Sunshield Deployment Sequence
Title HereLow-Cost Sunshield Deployment Sequence
Title HereLow-Cost Sunshield Deployment Sequence
Title HereLow-Cost Sunshield Deployment Sequence
Title HereLow-Cost Sunshield Deployment Sequence
Title HereLow-Cost Sunshield Deployment Sequence
Title HereComprehensive Science Mission Architecture
Atlas V 551
LHe Dewaror Cryocooler
3-Stage SunshieldWrap-Rib Deployment
3-Axis S/C
3-Stage V-Groove
Passively Cooled Mirrors
40 K
293 K
155 K
85 K
Gimballed AntennaSolar Panels
20 m
2.8 m
Receiver & Lenses
Title HereSensitivity with Existing Detector Arrays
AbsorbingBaffle (40 K)
Half-WavePlate (2 K)
PolyethyleneLenses (2 K)
TelecentricFocus
ApertureStop (2 K)
Focal Plane Bolometer Array
(100 mK)
Freq[GHz]
FWHM[arcmin]
NTD Ge Bolometers Planck
#[det’s]
NET/det*[Ks]
NET*[Ks]
NET/det†
[Ks]
30 155 8 69 24.5
40 116 54 60 8.2
60 77 128 49 4.4
90 52 256 42 2.6 102
135 34 256 38 2.4 83
200 23 64 41 5.1 134
300 16 64 95 11.8 404
Total 830 1.5
*De
sig
n S
ensi
tivity
†G
oal S
ensi
tivity
Instrument Technology NET [Ks] Value
HFI100 – 850 GHz
NTD Ge
Bolometer
20.3 Design Goal
< 16.7 Measured
LFI30 – 70 GHz
HEMT 68.9 Req’t
EPIC Projected Bands and Sensitivities
Planck Projected Sensitivities
Note modest detector improvement over Planck dueto relaxed time constant specification & 2 K optics
30 cm
Title HereNTD Bolometers for Planck & Herschel
SPIRE Low-power JFETs
143 GHz Spider-web Bolometer
Herschel/SPIRE Bolometer Array
NTD Germanium
Planck/HFI focal plane (52 bolometers)
Title Here
8 mm
Antenna-Coupled Bolometers for EPIC
Single Pixel – Dual Pol at 150 GHz (JPL/CIT)
Advantages
Small active volume.. 30 – 300 GHz operationBeam collimation…... Eliminates discrete feeds
Reduced focal plane massIntrinsic filters…….... No discrete components
Y-polarizationX-polarization
High OpticalEfficiency!
Measured Spectral Response
Kuo et al. SPIE 2006
Measured Beam Patterns
Title Here
New technologies bring enhanced capabilities…
Antenna-Coupled TES / MKID detectors Higher sensitivity, less mass & power Continuously rotating waveplate Better beam control Continuous ADR Less mass, no interruptions
…but we have the technology to do this mission today
Low-Cost Mission: High Technology Readiness
Technology TRL Heritage
Focal Plane Arrays (NTD Ge bolometers)
NTD thermistors and readouts
Antennas
8
4
Planck & Herschel
Wide-Field Refractor 6 BICEP
Waveplate (stepped every 24 hours)
Optical configuration
Cryogenic stepper drive
6
9
SCUBA, HERTZ, etc.
Spitzer
LHe Cryostat 9 Spitzer, ISO, Herschel
Sub-K Cooler: Single-shot ADR 9 ASTRO-E2 (single-shot)
Deployable Sunshield 4-5 TRL=9 components
Toroidal-Beam Downlink Antenna 4-5 TRL=9 components
Title HereTES Bolometer Arrays
Freq. Domain (UCB/LBNL) Time Domain (NIST)
SQUID Multiplexing
Antenna-Coupled TES Bolometers (UCB/LBNL)SCUBA2 Focal Plane (10,000 TES Bolometers)
Advantages
Multiplexing……. Larger array formatsHigher sensitivityFewer wires to 100 mKLow cryogenic power disp.
Faster response... Useful for larger aperture
Title HereLow-Cost Mission Focal Plane Options
TES Bolometer Option
Freq[GHz]
FWHM
[′]Nbol3
[#]
Required Sensitivity1 Design Sensitivity2
NET4 [Ks] T-5
[K ′]Tpix6
[nK]NET4 [Ks] T-5
[K ′]Tpix6
[nK]bolo band bolo band
30 155 8 87 30.8 66.7 560 62 22 33.4 280
40 116 54 77 10.4 22.7 190 54 7.4 11.3 95
60 77 128 66 5.8 12.7 107 47 4.1 6.3 53
90 52 512 59 2.6 5.6 47 41 1.8 2.8 24
135 34 512 59 2.6 5.7 48 42 1.9 2.8 24
200 23 576 72 3.0 6.5 55 51 2.1 3.2 27
300 16 576 145 6.0 13.0 110 100 4.2 6.5 55
Total7 2366 1.5 3.2 27 1.0 1.6 13
NTD Bolometer Option
Freq[GHz]
FWHM
[′]Nbol3
[#]
Required Sensitivity1 Design Sensitivity2
NET4 [Ks] T-5
[K ′]Tpix6
[nK]NET4 [Ks] T-5
[K ′]Tpix6
[nK]bolo band bolo band
30 155 8 98 34.6 106 630 69 24.5 53.1 315
40 116 54 85 11.5 35.4 210 60 8.2 17.7 105
60 77 128 70 6.2 18.9 110 49 4.4 9.5 56
90 52 256 59 3.7 11.3 67 42 2.6 5.6 34
135 34 256 53 3.3 10.2 61 38 2.4 5.1 30
200 23 64 58 7.2 22.1 130 41 5.1 11.0 66
300 16 64 135 16.7 51.4 310 95 11.8 25.7 150
Total7 830 2.1 6.5 39 1.5 3.3 19
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Input AssumptionsFractional bandwidth / = 30 % Optical efficiency = 40 %Focal plane temperature = 100 mK Optics temperature = 2 K, with 10 % couplingWaveplate temperature = 20 K, with 2 % coupling Baffle at 40 K with 0.3 % coupling (measured)Psat/Q = 5 for TES bolometers G0 = 10 Q / T0 for NTD bolometers
Title Here
Instrument Design Goal Instrument Requirement
Suppress raw systematic effect below statistical noise level
Suppress systematic errorsbelow r = 0.01 after correction
Systematic Effect Design Goal Mitigations Heritage
Main
Be
am E
ffects
Beamsize 1e-4
• Refracting telescope
• Waveplate before telescope
• Scan crossings & CMB dipole
BICEP†
SPIDER‡
---
Gain 8e-5
Beam Offset 5e-5Ellipticity 1e-3
Pol. Beam Rot’n 3e-4
Polarized Sidelobes 1 nKrms • Refractor + baffle BICEP*
1/f Noise 16 mHz
• Drift-scanned NTD bolometers
• Or TES + modulator
• Scan crossings
BOOMERANG*
EBEX/SPIDER/POLARBEAR‡
---
Scan-Synch Signals 1 nKrms • Scan redundancy ---
Optics Temp. Stability10 Krms s/s300 K/Hz
• Dual analyzers
• Temperature monitoring & control of all critical stages
Planck*
Planck*Focal PlaneTemp. Stability
3 nKrms s/s150 nK/Hz * = Already demonstrated to EPIC requirement
† = Proof of operation but needs improvement‡ = Planned demonstration to EPIC requirement
Systematic Error Mitigation Strategy
Title Here
BICEP
Wide-Field Refracting Optics
• Wide unaberrated FOV
• Excellent main beams
• Telecentric focus
• Waveplate = first optic
• Ultra-low sidelobes
• Field tested in BICEP
Title HereWide-Field Refracting Optics
Freq Band[GHz]
FWHM[arcmin]
FOV*[deg]
30 / 40 155 / 116 28
60 77 25
90 52 22
135 34 19
200 / 300 23 / 16 17
*Strehl ratio > 0.95
BICEP
Title HerePolarization Systematics: Main Beams
Differential FWHM
Differential Beam Offset Differential Ellipticity
Differential Gain, Rotation
Main Beam Instrumental Polarization Effects
Calculation- Difference PSB beam pairs- Parameterize main beam effects- Convolve w/ scan pattern- Calculate resulting power spectrum
Caveats- Calculation is conservative → single pixel- We can always apply post facto correction- Waveplate eliminates these effects
Title HereMain Beam Systematic Errors - Requirement
Title HereMain Beam Systematic Errors - Goal
Title HereMain Beam Properties at 135 GHz
PSF
Systematic Goal* Req’t* Calc† Meas‡
Gain (g1-g2)/g 8e-5 3e-4 2e-4 < 5e-3
Beam Size (1-2)/ 1e-4 3e-4 1e-4 < 2e-3
Beam Offset /2 5e-5 2e-4 4e-6 6e-3
Ellipticity (e1-e2)/2 1e-3 3e-3 1e-4 < 1e-3
Pol. Rotation 3e-4 1e-3 5e-6 8e-4 *Goal: Suppress effect without correction below noise**Req’t: Suppress effect with correction below r = 0.01 †Calc: Worst performance over the FOV at 135 GHz‡Meas: Median value measured in BICEP receiver
Difference BeamPSF Difference Beam
Performance at FOV Center
Performance at FOV Edge
Title HereMeasured Beam Offsets in BICEP
Title Here
BICEP Measurements Sky at 100 GHz
Levels below 3 nK for most of the sky!
Far-Sidelobe Performance
~ 20% polarized
3nK
10
100
30
1 K
10
100
1e3
1e4
1e5
Sidelobe Map at 100 GHz
Title HereForegrounds - What We Know Today
75% of sky 75% of sky
2% patch 2% patch
3. Results• Removal gives a modest sensitivity loss• Better sensitivity → better subtraction (model is linear)
4. Conclusion: FGs Look Manageable!• Preliminary. We might find a new component tomorrow• We don’t know where a linear model fails
Sensitivity per 14′ Pixel
EPICWMAP-8Planck
Case Required Sens. Design Sens.
No foregrounds 35 12
s and d fixed 50 17
s and d fitted
in 30˚ patches55 18
s and d fitted
in 30˚ patches70 22
ComponentSpectrum
(I )Amplitude (Stokes I)
Pol. fraction
CMB =0 70K 1%
Synchrotron =-3.0 40K @ 23GHz 10%
Free-free =-2.15 20K @ 23GHz 1%
Thermal DustFDS model 8
(~+1.7)10K @ 94GHz 5%
Spinning Dust DL98 (WNM) 50K @ 23GHz 2%
nKCMB in 2˚ pixels
2. Multi-band Removal• Fit only synch & thermal dust• Fit components spectrally• Let indicies float spatially
Eriksen et al. 2006
Input Sky Model
Resulting Sensitivity After Subtraction
1. Input Sky Model• All components we know about today
Title HereConclusions
Exciting CMB science in the post-Planck era § Clear role for gravitational-wave polarization science in space § High-ℓ science compelling but need for space is less robust
Imaging polarimeter approach § Technically and scientifically feasible § Simple technique, established history. § Simple scaling to higher sensitivity: improve the focal plane. § Design in extensive control of systematics from the beginning § Low-Cost option → meets Weiss Committee guidelines for GW science § Comprehensive Science option → more capable, more science, more $
Foregrounds § What we know today about polarized foreground shows they can be subtracted below r = 0.01
Technologies § We can build a very capable mission today with existing technology § New technologies will improve the mission & reduce technical risk