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Néel people involved in NIKA

Néel people involved in NIKA. Researchers: Engineers/Technicians: Alain Benoit Gregory Garde (mechanics) Aurelien Bideaud Julien Minet (FPGA) Philippe Camus Henri Rodenas (cryogenics) Xavier Desert (LAOG) Christian Hoffmann Alessandro Monfardini Markus Roesch (IRAM PhD)

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Néel people involved in NIKA

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  1. Néel people involved in NIKA Researchers:Engineers/Technicians: Alain Benoit Gregory Garde (mechanics) Aurelien Bideaud Julien Minet (FPGA) Philippe Camus Henri Rodenas (cryogenics) Xavier Desert (LAOG) Christian Hoffmann Alessandro Monfardini Markus Roesch (IRAM PhD) Loren Swenson Coming soon (PhD): A. Cruciani (now at Roma)

  2. NIKA is for 2mm ! Credit: S. Leclercq 94±18 GHz, 146±20 GHz, 240±45 GHz, 345±12 GHz 3mm2mm1.25mm0.85mm

  3. Cardiff Filters Credit: C. Tucker Band: 125-170GHz

  4. 2.5 arc-min DCMB+NIKA for IRAM Dilution Cryostat built at Institut Nèel as a test bench for different focal planes. Telecentric in image space feff = 51.6m

  5. Horizontal dilution cryostat views • - LHe and PT versions • - Tbase < 100mK • - LN2-free • - Horizontal • Large cooling-power • Fast cool-down (12h) Baffle + detectors box All at < 100mK Mixing Chamber

  6. 300K 0.1K 150K 80K 4K NIKA optics 1K

  7. NIKA datasheet M7 • On the cryostat (horizontal): • - M7 (flat) • M8 (x-y 2nd degree polyn.) • at the IRAM focal plane (f/10) • In the cryostat: • 4 K HDPE lens • - 100 mK HDPE lens M8 Cryostat window Pixel pitch: 1.6 mm ( = 2.05mm, f/1.7 optics  Nyquist) Array dimensions: 3232 mm2 Number of pixels: up to 2020 (2.42.4arc-min, pixels spacing 7.2 arc-sec) 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.

  8. Cryostat 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)

  9. IN OUT Home-made feedthroughs (no UHV) 300K Stainless Steel 2.2mm semirigid cables External conductor thermalisation (soldered) 150K Stainless Steel 2.2mm semirigid cables 80K External conductor thermalisation (soldered) Stainless Steel 2.2mm semirigid cables 4K External conductor thermalisation (soldered) + 2 DC blocks for inner conductor + LNA NbTi 1.6mm semirigid cables 1K External conductor thermalisation (glued) NbTi 1.6mm semirigid cables 50mK 2 (inner) DC blocks Copper 2.2mm semirigid cables (10-20cm) External conductor thermalised one last time (soldered) KIDs KIDs cabling

  10. High-Q resonators Example of high-Q measured in this environment Measured 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.

  11. 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 Tbase= 75mK we see that: • if 77K at cryostat input Tbolos= 95mK  P1=2.4 pW • if 300K at cryostat input Tbolos= 110mK  P2=5 pW • In the ideal World P1P2/4=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 window • 2) In any case the 300K HDPE window is emitting • Let see with the new filters…

  12. LEKIDs 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.

  13. BIG HORIZONTAL VERTICAL POLARIZATION HORIZONTAL POLARIZATION SMALL HORIZONTAL NO ANTENNA BIG VERTICAL Making 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. Polarization response is reasonable

  14. New multi-antennas design In fabrication in Orsay (IEF and CSNSM)

  15. Electronics for NIKA

  16. FPGA prototype ALTERA evaluation board (STRATIX-II) 2 ADC 12-bit 125 MSPS + 2 DAC 14-bit 160MSPS

  17. FPGA multiplexing I-Q mixers for UP/DOWN CONVERSION DDC CONVERSION IN FPGA

  18. FPGA Multiplexing • 8 channels have been recently • demonstrated. • Full chain: • - tones generation • UP/DOWN conversions • Real high-Q resonators seeing • light (no antennas !) • FPGA ressources occupation • around 24%. 32 channels are • in principle feasible on the • small board (requiring some • optimisation probably).

  19. Plans for MUX readout • Bonn 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 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 board is under • development at LPSC Grenoble. Will work for 64-128 channels. Fully • designed and realised in-house, so potentially allows to be adapted for any • new application we might imagine in the future (and open to hardware • improvements). • IRAM is participating to the Mazin Open Source project for • developing a 128 channels module. Expected in Autumn 2009.

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