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The Italian View of B-Pol P. de Bernardis and the Italian team. The Italian HW groups :. Milano (Bersanelli, Mennella et al.) Milano Bicocca (Gervasi, Sironi, et al.) Torino (Tascone et al.) Bologna (Carretti, Cortiglioni, Mandolesi, Valenziano, Villa, et al.) Firenze (Natale et al.) - PowerPoint PPT Presentation
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The Italian View
of B-Pol
P. de Bernardisand the
Italian team
The Italian HW groups :
• Milano (Bersanelli, Mennella et al.)• Milano Bicocca (Gervasi, Sironi, et al.)• Torino (Tascone et al.)• Bologna (Carretti, Cortiglioni, Mandolesi, Valenziano, Villa, et al.)• Firenze (Natale et al.)• Roma La Sapienza (de Bernardis, De Petris, Masi et al.)
Heritage:
BOOMERanG, Planck-HFI, Planck-LFI, SPORT, Bar-SPORT, OLIMPO
All started in the COFIS study of “Themes and Models in Cosmology and Fundamental
Physics”funded in 2004 by the Italian Space Agency
ASI studies• The Italian Space Agency
has supported in 2004 a study on “Themes and Models in Cosmology and Fundamental Physics from Space”.
• All the members of the Italian cosmology community have contributed to this study, which was delivered on Oct. 20, 2004.
• Top priorities resulting from the study:
Piano Aerospaziale Nazionale 2006-2008 Agenzia Spaziale Italiana
http://www.asi.it/html/ita/news/20060124_Executive_Summary.pdf
Orbit L2 (baseline), LEO or MEO
Scanning strategy Spinning at about 1rpm. TBD
Optics 4 small telescopes (aperture of about 60 cm each); large non distorted focal surface; low sidelobes; low spurious polarisation
Angular resolution 10-20 arc min at 100 GHz (typical)
Frequency range 40-120 GHz (HEMT); 60-220 GHz (Bolometers)
Bandwidth 10% (typical)
Number of detectors 100 to 1000 (sensitivity up to 30 times better than Planck)
Detectors HEMT radiometers (at 20 K) or Bolometers (100-300 mK), TBD
Number of frequencies
3 (HEMT); 3 (Bolometers); 6 (HEMT + Bolometers) TBD
Cryogenics Active and Passive techniques TBD
Bus PRIMA
Data rate Compressed, typically 10 GB per day
Carrier VEGA
Tab. 2‑1: Overview of the driving mission requirements for the B-POL satellite .
EXAMPLE
No real instrument study, yet• Many issues require further experimentation -
thinking.• The most important ones are:
– Mass production of detectors (sensitivity)– Knowledge of polarized foregrounds and optimization of
sky coverage / sky scan– Instrumental Systematics– Polarization modulation
• For these reasons we do not have a full proposal• Here we want to give contributions for discussion
• At variance with interferometers, Bolometer technology is easily scalable, and the throughput can be larger than 2.
• Focal planes hosting thousands of bolometers are being developed already.
• Intense activity in this field is ongoing in Berkeley, JPL-Caltech, Cardiff, SRON …
• How many detectors do we really need for a B-modes survey ?
Sensitivity
A. Lee, Berkeley
r = 0.03FWHM = 0.5°, T=1 yearNET = 150 K/sqrt(Hz)
FWHM = 0.5°T=1 yearNET = 150 K/sqrt(Hz)
500 detectors10000 detectors
50%
Cfr. Challinor & ChonAstro-ph/0410097
Analysis by G. Polenta
Mass production of detectors in Italy
Italian TESs :• GASTALDO L., GALLINARO G., GATTI F., PERGOLESI D., RIBEIRO GOMES
M., REPETTO P., DUSSONI S., VALLE R., MANFRINETTI P., CHINCARINI A. (2006). Study of the δ-Al/Ag superconducting alloy for TES applications. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION A, ACCELERATORS, SPECTROMETERS, DETECTORS AND ASSOCIATED EQUIPMENT. vol. 559 pp. 465-467 ISSN: 0168-9002 2.
• GATTI F., PIRO L., PERGOLESI D., COLASANTI L., GASTALDO L., RIBEIRO GOMES M., REPETTO P. (2006). TES microcalorimeter development for future Italian X-ray astronomy missions. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION A, ACCELERATORS, SPECTROMETERS, DETECTORS AND ASSOCIATED EQUIPMENT. vol. 559 pp. 605-607 ISSN: 0168-9002
PRIN 2006• We have setup a national collaboration to develop
a large-format, polarization-sensitive bolometer array camera at 90 GHz.
• This is a collaboration of the following groups– Roma (de Bernardis, Masi, Vittorio, Dall’ Oglio) – Milano (Bersanelli, Gervasi)– Genova (Gatti)– Bologna (Mandolesi)– Padova/Trieste (De Zotti – Pasian)
• The camera, based on Horn-coupled TES bolometers, will fill with 300 detectors the corrected focal plane of a 2.6m telescope (we have one in the Alps (MITO), one in Antarctica (COCHISE) and a balloon-borne one (OLIMPO).
Det. architecture, Cryogenics, ReadoutPassive Frontend
TES, wafer processing
Passive frontend
Analysis, science
RICRivelatori a
Induttanza CineticaLa Sapienza - RomaIRST-ITC – Trento
INFN funds+ Cardiff (Mauskopf)
R C
KIDKinetic Inductance
DetectorsLa Sapienza - RomaIRST-ITC – Trento
INFN funds+ Cardiff (Mauskopf)
R C
R C
Mazin (Caltech)
GHz RF (…+fN-1+fN+fN+1+…)
CMB CMB CMB
Pixel N-1fN-1
Pixel NfN
Pixel N+1fN+1
0.3K - 0.1K R C
RF mux• A KID has high transmission at f away from resonance.
This fact can naturally be used for multiplexing many detectors, tuned at different resonances f, all loading the same transmission line.
• Using excitation in the GHz range:
• high quality wireless components are available
• thousands of detectors can be multiplexed, with a single coax and a single HEMT
R C
Al resonators process (IRST-ITC)
Al resonators (IRST-ITC)
La Sapienza: Measurement Testbed
5-10 GHz
0.3K
Pulse Tube Refrigerator and 3He/4He fridge
Directional DetectorKrytar 1820
Detector Krytar 201
Front-End devices Made in Italy
• Corrugated feed horn at 44 GHz
• Designed, made (by electro-erosion on aluminum) and tested in Italy
•Milano Group (Bersanelli, Mennella et al.)
• Corrugated feed horn at 44 GHz
• Designed, made (by electro-erosion on aluminum) and tested in Italy
•Milano Group (Bersanelli, Mennella et al.)
Riccardo Tascone et al.:Five-Level Waveguide
Correlation Unit (European Patent, 05019553.6)
Ka band
Impressive
Performance:
,
V
IK
U
QH
U
Q
m
m
Figure 4. Spectral distribution of the elements of K
.
Figure 3. Spectral distribution of the elements of H
.
R. Tascone et al.
OMTfor Ka band
28 30 32 34 36-60
-50
-40
-30
-20
-10
0
S33
(meas) S
33 (simul.)
S44
(meas.) S
44 (simul.)
mag
nitu
de [d
B]
f [GHz]
28 30 32 34 36-80
-70
-60
-50
-40
isolation S21
cross-coupling S41
cross-coupling S32
mag
nitu
de [d
B]
f [GHz]
Return Loss at each of the four ports > 30 dB;
Isolation of 70 dB;Cross-couplings of -65 dB;
Group Delay equalization within ± 5 ps;
Insertion Loss < 0.1÷0.2 dB.
• Can all this be extended to higher frequencies, keeping the same performance ?
• Under study.
Cryogenics Made in Italy:
devices and cryostats
FETBOX
CQM
on
Planck
FETBOX Flight Model
The JFET BOX: 72 diff. Channels, < 200mW @ 50K, 5 nV/sqrt(Hz)
130K50K
50K
130K50K
50K
D. Brienza et al., “Cryogenic Preamplifiers for high resistance bolometers”, WOLTE-7 - ESA-WPP-264, pg. 283-288, (2006).
Sun Shield
Ground Shield
Solar Array
Cryostat and
detectors
Primary Mirror
(1.3m)
Differential GPS Array
Star Camera
the BOOMERanG balloon-borne telescope
B03 Sensitive at 145, 245, 345 GHz
S. Masi et al. Cryogenics, 39, 217-224, 1999
The The FridgeFridgeCryopumpIt works with charcoal carbon grains
It adsorbs when T < 12 K (mechanical thermal switch)
It desorbs when T > 20 K (heater)
Condensation pointThermally connected to the 4He bath with 2 gold plated high purity copper rods
Pumping tubesThin wall stainless steel tubes
Liquid 3He evaporatorT = 0.280 K
Volume = 130 cm3
34 STP liters of 3He gas
Holding time: 14 days
S. Masi et al. Cryogenics, 38, 319-324, 1998
ASI-OLIMPOCryostat for 130 bolometric detectors (both TESs and Semiconductors)
• PILOT - CNES
Cryostat for large bolometer arrays (1024@240m + 1024@550m)Main challanges: • Radiation shields • Thermalization of bolo cables• Weight & Size
Industrial support for Cryogenics
• In Italy:
– Alenia– CECOM– Galileo Avionica– LMP– RIAL– ….
Calibration DevicesMade in Italy
S. Masi et al. 2006, A&A, 458, 687-716 , astro-ph/0507509
The “Paolorizer” for BOOMERanG-B03
XPol<1x10-3
• We also had a calibration lamp in the Lyot stop of BOOMERanG and..
• … surprise surprise, it is polarized !
Cal Lamp
The LFI calibrationThe LFI calibration
BB calibrator
LFI cold loads
RCA AIV (2/2)RCA AIV (2/2)
Inputs for discussion(from recent Italian brain-storming)
• Scientific Objectives:– E–modes free from systematic effects– B– modes at the best we can do– lmax = ~ 500 for distinguish primordial B mode from lensing B
mode– Precise polarized foreground maps (~ 0.1 uK) for systematics and
astrophysics
• 1st Level Requirements:– L2 orbit (for systematic effects)– Frequency Coverage: 20 GHz to 500 GHz would be ideal for
accurate cleaning of the various classes of foregrounds and astrophysical studies. Low end difficult due to telescope size.Feasibility of a strictly linked ground based program ?
– Sky coverage: Full sky– Detector Technology: different technologies exist. It would be
good to crosscheck systematics with at least one frequency band with different technology
– Polarimetry needed
• 2nd Level Requirements– Sensitivity: < 0.1 mK * sec^(-1/2). See note (*)– FWHM: depends on science. See note (**)– Lifetime: 4 full sky surveys 2 years– Number of detectors: few 103 / frequency. See note (***)– Technology: HEMT from 20 to 100; Bolometers from 70 to 500 GHz. – Cryogenics: Depending on the detectors used (type, number,
dissipation) and mission requirements (lifetime, spacecraft size etc.), the mission cryo chain could be a combination of the following possible systems:
• From 300K to ~50K, ~3 passive radiators (V-Grooves?) in L2; or their combination with active coolers, mechanical (low vibration) or sorption, to reduce number/dimensions of passive stages
• Below ~50K – sorption/JT cooler with H2 or Ne + sorption/JT He – mechanical cooler (pulse tube, vibration level?)– Liquid/solid cryogens
• From ~5K to 0.1K, – dilution cooler– ADR
– OMT based architecture for high purity polarization measurements.
Frequency (GHz)
lmax Required Diameter (meter)
20
500 3.5
1000 6.5
1500 10
100
500 0.7
1000 1.3
1500 2.0
500
500 0.1
1000 0.3
1500 0.4
30 dB taper
Separate telescopes for different bands ?
• Appealing option because– It allows to mazimize the size of polarization-pure focal
planes– It reduces integration complexity
• If on two separate satellites: easier optimization of scan strategy (4 Planck satellites can be fitted inside the ARIANE V) .
• Moving bands to GND and Balloons will help with budget !