11

Néel people involved in NIKANéel people involved in NIKA

Researchers:Researchers: Engineers/Technicians:Engineers/Technicians:

Alain BenoitAlain Benoit Gregory Garde (mechanics)Gregory Garde (mechanics)Aurelien BideaudAurelien Bideaud Julien Minet (FPGA)Julien Minet (FPGA)Philippe CamusPhilippe Camus Henri Rodenas (cryogenics) Henri Rodenas (cryogenics)Xavier DesertXavier Desert (LAOG)(LAOG)Christian HoffmannChristian HoffmannAlessandro MonfardiniAlessandro MonfardiniMarkus Roesch (IRAM PhD)Markus Roesch (IRAM PhD)Loren SwensonLoren Swenson

Coming soon (PhD):Coming soon (PhD): A. Cruciani (now at Roma) A. Cruciani (now at Roma)

22

NIKA is for 2mm !NIKA is for 2mm !

94±18 GHz, 146±20 GHz, 240±45 GHz, 345±12 GHz 3mm3mm 2mm2mm 1.25mm1.25mm 0.85mm0.85mm

Cre

dit

: S

. Lec

lerc

q

33

Cardiff FiltersCardiff FiltersC

red

it:

C. T

uck

er

Band: 125-170GHzBand: 125-170GHz

44

2.5 arc-min DCMB+NIKA for IRAM2.5 arc-min DCMB+NIKA for IRAM

Dilution Cryostat built at Institut NèelDilution Cryostat built at Institut Nèelas a test bench for different focal as a test bench for different focal planes. planes.

ffeffeff = 51.6m = 51.6mTelecentric in image spaceTelecentric in image space

55

Horizontal dilution cryostat viewsHorizontal dilution cryostat views- LHe and PT versions- LHe and PT versions- Tbase < 100mK- Tbase < 100mK- LN2-free- LN2-free- Horizontal- Horizontal- Large cooling-powerLarge cooling-power- Fast cool-down (Fast cool-down (12h)12h)

Mixing Mixing ChamberChamber

Baffle + detectors boxBaffle + detectors boxAll at < 100mKAll at < 100mK

66

NIKA optics NIKA optics

300K

150K

80K 4K

0.1K1K

77

NIKA datasheetNIKA datasheet

Pixel pitch:Pixel pitch: 1.6 mm ( = 2.05mm, f/1.7 optics Nyquist)Array dimensions:Array dimensions: 3232 mm2

Number of pixels:Number of pixels: up to 2020 (2.42.4arc-min, pixels spacing 7.2 arc-sec)Read-outs:Read-outs: FFTS (Bonn): 64 channels (for now)

REALLY low-cost FPGA (up to 24-32 channels)LPSC - US

Number of cables from the cryostat: 2 coax (f < 8 GHz), 3 for preamplifier bias. Number of cables from the cryostat: 2 coax (f < 8 GHz), 3 for preamplifier bias.

On the cryostat (horizontal):On the cryostat (horizontal):- M7 (flat)- M7 (flat)- M8 (x-y 2M8 (x-y 2ndnd degree polyn.) degree polyn.) at the IRAM focal plane (f/10)at the IRAM focal plane (f/10)

In the cryostat:In the cryostat:- 4 K HDPE lens4 K HDPE lens- 100 mK HDPE lens- 100 mK HDPE lens

M7M7

M8M8Cryostat windowCryostat window

88

Cryostat StatusCryostat Status

- Base Temperature 60 mK- Cooling Power at 100 mK 10-100 W- Number of “useful”cooldowns so far 10- To close and start pumping 1 hour- Pumping time (small pump) 3-6 hours- From 300K to 4K 6-7 hours- From 4K to 100mK 4-6 hours- Helium to cool down and refill once 100 liters- Helium consumption at base T 1 liter/h- Total Cool-down time 14-18h

- Cabled for KIDs (LNA at 4K) and Semiconductors (JFETs at 120K)

99

KIDs cablingKIDs cabling

Home-made feedthroughs (no UHV)

External conductor thermalisation (soldered)

Stainless Steel 2.2mm semirigid cables300K

150K

80K External conductor thermalisation (soldered)Stainless Steel 2.2mm semirigid cables

4KStainless Steel 2.2mm semirigid cables

External conductor thermalisation (soldered)+ 2 DC blocks for inner conductor + LNA

1K

50mK

External conductor thermalisation (glued)

NbTi 1.6mm semirigid cables

ININ

KIDs

NbTi 1.6mm semirigid cables

Copper 2.2mm semirigid cables (10-20cm)

External conductor thermalised one last time (soldered)

2 (inner) DC blocks

OUTOUT

1010

High-Q resonatorsHigh-Q resonators

Example of high-Q measured in this environmentMeasured in SRON (not same chip, but same bunch) Qi 3·106 Here we have Qi 2·106 Still not the same, but not even completely off.

1111

Something to discuss ?Something to discuss ?

Waiting for the real filters …. Everything to be measured again. With the old DIABOLO filters + a single layer 2-mm passband mesh we estimate the following.

From a well-known (dark R-T, I-V etc.) NbSi antenna-coupled array:

When TWhen Tbasebase= 75mK we see that:= 75mK we see that:- if 77K at cryostat input Tif 77K at cryostat input Tbolosbolos= 95mK = 95mK PP11=2.4 pW=2.4 pW- if 300K at cryostat input Tif 300K at cryostat input Tbolosbolos= 110mK= 110mK PP22=5 pW=5 pW

In the ideal World P1P2/4=1.25pW. So we have a kind of plateau of 1-1.2pW (absorbed !) that remain somewhat unexplained.

But: 1) The 77K ECOSORB was a bit smaller than the window2) In any case the 300K HDPE window is emitting

Let see with the new filters…

1212

LEKIDs design for IRAMLEKIDs design for IRAM

Samples fabricated by Markus at IRAM in Nb and Al. Tests on Nb samples performed here at 2K. Problems: Cross-talk between resonators (design to be improved); sputtered Al films of poor quality (alternative deposition). But some good news too (see Cardiff, Roma).

A new mask is almost ready to order.

1313

Making progresses on the antennasMaking progresses on the antennas

LN2/300K chopper on focal plane

Optics OK: de-magnification factor 6 (from f/10 to f/1.6); side-lobes not bad.side-lobes not bad.

Polarization response is reasonable

BIG HORIZONTAL

NOANTENNA

SMALLHORIZONTAL

BIG VERTICAL

VERTICAL POLARIZATION

HORIZONTAL POLARIZATION

1414

New multi-antennas designNew multi-antennas design

In fabrication in Orsay (IEF and CSNSM)

1515

Electronics for NIKAElectronics for NIKA

1616

FPGA prototypeFPGA prototype

ALTERA evaluation board (STRATIX-II)ALTERA evaluation board (STRATIX-II)2 ADC 12-bit 125 MSPS + 2 DAC 14-bit 160MSPS2 ADC 12-bit 125 MSPS + 2 DAC 14-bit 160MSPS

1717

FPGA multiplexingFPGA multiplexing

DDC CONVERSION IN FPGA

I-Q mixers for UP/DOWN CONVERSION

1818

FPGA MultiplexingFPGA Multiplexing

8 channels have been recently demonstrated.

Full chain:Full chain:- tones generation- UP/DOWN conversions- Real high-Q resonators seeinglight (no antennas !)

FPGA ressources occupation around 24%. 32 channels are in principle feasible on the small board (requiring some optimisation probably).

1919

Plans for MUX readout Plans for MUX readout

- Bonn FFTS boardBonn FFTS board + new DAC board of course. 64-128 channels are ALREADY feasible. But not available yet in Grenoble for testing and interfacing with the acquisition software. Problem should be fixed in the next month.

- Our small FPGA boardOur small FPGA board should be OK for up to 24 channels at least.Using it also for other resonators applications.

- A similar (but 400MHz and bigger FPGA) custom boardcustom board is under development at LPSC GrenobleLPSC Grenoble. Will work for 64-128 channels. Fully designed and realised in-house, so potentially allows to be adapted for anynew application we might imagine in the future (and open to hardware improvements).

- IRAM is participating to the Mazin Mazin Open Source projectOpen Source project for developing a 128 channels module. Expected in Autumn 2009.