Components, Receivers, and Instrumentation for Ground-Based mm/submm Astronomy B.Lazareff, G.Butin, M.Carter, J.Y.Chenu, A.L.Fontana, S.Mahieu, D.Maier,

Components, Receivers, and Instrumentation for Ground-Based

mm/submm Astronomy

B.Lazareff, G.Butin, M.Carter, J.Y.Chenu, A.L.Fontana, S.Mahieu, D.Maier, F.Mattiocco,

P.SerresK.Schuster, N.Krebs, T.Scherer, M.Schicke

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Outline

• Existing facilities• Drivers for development• Component technologies• Ultimate limits

• Device development at IRAM• SIS Mixers• Receiving systems• Instrumentation

• Future prospects

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Present and Future Facilities

• IRAM • ALMA

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Drivers for Receiver Development

• Sensitivity ! Ultimate limit: background limited• Receiver : electronics, optics• Atmosphere• Photon statisitics

• Frequency coverage• Tuning range. All atmospheric windows• Instantaneous. Goal: one atmospheric window, several 10's

of GHz!

• Speed (mapping)• But also:

• Stability: amplitude, phase• Linearity• Polarization purity• Reliability• Cost (hardware and manpower)

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Active Component Technologies

SIS

HEMT HEB

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Active Component Technologies

• HEMT• Direct amplification 115 GHz on telescopes; 200 GHz in the lab• Instantaneous b/w ~ 30%

• SIS• Heterodyne mixing 700GHz (Nb); >1THz (NbTiN)• Instantaeneous b/w 2 x 8 GHz

• HEB• Heterodyne mixing Several THz• Instantaeneous b/w ~ 4 GHz

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Active Component Technologies

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Pushing the Limits of Ground-Based Observing: 1.037 GHz !

Meledin et al 2004

CFA, Cambridge, MA

Moscow State University

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Quantum Limit for SIS mixers(after A.R.Kerr)

Receiver type SSB DSB

Calibration type SSB SSB DSB

Tsys kh / kh / kh 2/

Tmxr kh 2/ 0 0

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Fundamental Limits versusState-of-Art (ALMA specs, SSB)

Quantum

Atm (0.5mm PWV, 1.4 airmass)

ALMA SSB Spec

Practical limit

kh /1

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Devices : SIS Junction Devt & Fab

Area (m2)

Area Tol. (%)

Critical current density (kA/cm2)

Quality RSG[2mV]/RN

Process Yield (%)

1-4 10 6-15 15-30 >60

P2-I1-43.41-3

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5 6

Voltage [mV]

Cu

rren

t [µ

A]

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Devices : SIS Junction Devt & Fab

• PdBI Band 1 (83-116 GHz)junction

• ALMA Band 7 (275-373 GHz)junction

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Devices : HEB Mixer Devt & Fab

Evolution of Tc with NbN film thickness

0

10000

20000,0

4 8 12 16 20

Temperature [K]

R [Ohm] 2.5 nm

3.3 nm

4.2 nm 5.8 nm

8.3 nm 12.5 nm

Optimisation systématique des films minces NbN

Mélangeur NbN : Courbe I/V et puissance IF

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Devices : MEMs : Tunable Capacitors

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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SIS Mixers

• DSB• SSB• 2SB (sideband separating)

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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DSB Mixers : Results

IRAM ALMA B7

Trec = 2 h/k

SRON ALMA B9

Trec = 3 h/k

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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SSB Mixers (PdBI) : Principle of Operation

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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SSB Mixers; Results for PdBI 200-260 GHz

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Sideband Separating (2SB) Mixersfor ALMA Band 7

Band 7 (IRAM)275 – 373 GHz

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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2SB SIS Mixer: Principle of Operation

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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ALMA Band 7 (IRAM) 2SB MixersResults

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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ALMA Band 7 (IRAM) 2SB MixersMore Results

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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ALMA Band 7 (IRAM) 2SB MixersMore Results

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Receiving Systems : PdBI

New generation receivers for PdBI. 4 frequency bands Dual-Pol 4GHz wide IF#1 unit currently undergoing system test

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Receiving Systems Atmospheric Phase Correction

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Receiving Systems : ALMA B7 Cartridge

• 275 – 373 GHz• Dual polarization• Dual sideband

USB+LSB• Four IF outputs

4 – 8 GHz• 147 K SSB

maximum• And many more

specs…

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Instrumentation : Antenna Range

• Herschel B1 horn verification

• 50 dB dynamic range @ 604 GHz

• ALMA B7 cartridge, optics verification

• >50dB dynamic range @ 300 GHz

arg Sbeam( )

20 log Sbeam 0.001( )( )

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Instrumentation : Vector Network Analyzer. 80 – 370

GHz

260 280 300 320 340 360

-60

-50

-40

-30

-20

-10

0

10

260 - 370 GHz MNVA multi holes coupler model and measurement

Leve

l [ d

B ]

Frequency [ GHz ]

Model losses (without conductivity losses) Model coupling Model isolation Measured coupling Measured isolation Measured losses

19-20 Sep 2005 Hunt for Molecules. Rx Devt for IRAM & ALMA Telescopes. B.Lazareff

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Where Do We Go from Here ? Areas for Future Work

• Array receivers for mapping speed• Push the IF b/w of SIS receivers to the limits:

f/f ~ 10% ?• Design integrated pixels• Push HEMT receivers to lower noise and higher

frequencies:• 30K over 85 – 115 GHz ?• ?? over 130 – 170 GHz ?

• Any really new detector around the corner ?• Keep our spectral bands pollution-free !