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K inetic I nductance D etectors for CoRE-like applications. Potentially involving (from the technical point-of-view): Grenoble (Néel, LPSC, IRAM, IPAG, CEA-LETI) Cardiff (others in UK ?) The Netherlands (SRON, Delft) Paris (APC, CSNSM, IAS, SaP) Roma Spain .. others ?. f.
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Kinetic Inductance Detectors for CoRE-like applications • Potentially involving (from the technical point-of-view): • Grenoble (Néel, LPSC, IRAM, IPAG, CEA-LETI) • Cardiff (others in UK ?) • The Netherlands (SRON, Delft) • Paris (APC, CSNSM, IAS, SaP) • Roma • Spain • .. others ? A. Monfardini, IAP 26/06/2012
f Light: increase in Lk Change in phase () A Light: increase in R Change in amplitude (A) KIDs working principle The incoming photons break Cooper pairs (supercurrent carriers) in a superconducting LC resonator measurable signals Dark, T << Tc IN-OUT transmission (amplitude) From the theory : f LK P f = frequency shift P = incoming power IN-OUT transmission (phase) f fi A. Monfardini, IAP 26/06/2012
Intrinsic linearity demonstrated Measured using the NIKA Sky Simulator f0 2 GHz ( h· << k·T ) A. Monfardini, IAP 26/06/2012
KIDs: multiplexing principle IN from DAC and UPCONVERTER OUT to DOWNCONVERTER and ADC f0 f1 fN-2 fN-1 …… Lumped Element KID design : High-Q superconducting (R 0) LC resonator : Feedline 50 Inductance LK + LG • One of the C lines is modulated by lithography to • adjust every resonance (e.g. fres 1.5 0.2 GHz) • natural f-domain multiplexing • since f/f 105 high MUX factor is possible Capacitor C A. Monfardini, IAP 26/06/2012
State-of-the-art A. Monfardini, IAP 26/06/2012
Snapshot taken today • ACHIEVED (mm and sub-mm applications): • Background limited (best pixels) for ground-based applications (150-350 GHz) • Electrical NEPs in the low 10-19 W/Hz0.5 • Optical NEPs under small loading (0.1pW) in the low 10-18 W/Hz0.5 (in Al and TiN) • Full system (hundreds pixels) up and running on a big telescope (NIKA) • Fundamental solutions found for photometric calibration (modulated read-out) • larger interest in the Community getting exponential • ONGOING: • kilo-pixels arrays uniformity to be investigated (e.g. NIKA, MUSIC, AMKID ...) • space-adapted configurations (main problem: cosmic-rays interaction) • ...... HUGE evolution from the last « BPol » meeting A. Monfardini, IAP 26/06/2012
NIKA run 3 – October 2011 150 GHz & 240 GHz – 132+132 pixels LEKIDs One week « mostly nights » run at the 30-m IRAM telescope NEFD 20 mJys0.5 Design: Grenoble Fabrication: Grenoble Electronics: Grenoble-US NEFD 100 mJys0.5 Design: Grenoble Fabrication: Grenoble Electronics: Grenoble-US • NIKA 2011 : • cryogen-free cryostat • magnetic screening • improved photometry (< 10%) • dual polarisation Sensitivity at 2 mm is now comparable to state-of-the-art TES (e.g. NASA Goddard). NEP 10-16 W/Hz0.5 A. Monfardini, IAP 26/06/2012 DR21(OH) star-forming region
NIKA run 4 First permanent KID camera - 06/2012 Available for Science until 2015.. waiting for the big (6.5’) Camera Sensitivity improved at 1.25mm, more pixels (132+224) A couple of dedicated observational runs (open to IRAM Community) per year. A. Monfardini, IAP 26/06/2012
1,020 pixels (150 GHz) • 2,000 pixels (240 GHz) 80 mm Kilo-pixels arrays: NIKA v0 3/4 feedlines OK (750 pixels). Resonances OK, Optical response OK. For detailed testing (e.g. noise, cross-talk) need 4 final NIKA electronics boards (NIKEL v1) A. Monfardini, IAP 26/06/2012
TiN LEKID optical sensitivity Design « NITA 1.2»: classical LEKID meander – not particularly optimised. Films: TiN JPL (H.G. Leduc) Way too sensitive. Must mount a diaphragm at the cold (0.1K) pupil to reduce the optical loading by a factor 60-70 with respect to the NIKA standards ( 10 pW per pixel). Power per pixel: << 1pW (band 125-170GHz). Example (7/2/2012 optical measurements): P = 0.04pW per pixel (80K vs. 0K on focal plane) is detected, on 64 typical pixels, with a S/N per unit band of 2000 8000 Hz0.5 (median 4000) Means, for this loadings, an opticalNEP of 5·10-18 to 2·10-17 W/Hz0.5, constant in the range 0.1 10 Hz ! Caution 1: to be confirmed by further measurements ! Caution 2: changing the T working point we have noticed large variations in the optical response. Must measure again at slightly higher T. Measurements reported here performed at 85 mK (working point not optimized, but since we don’t understand everything .... better being prudent). A. Monfardini, IAP 26/06/2012
Noise decorrelated < 10-17 W/Hz0.5 Credit: Juan Macias-Perez (LPSC Grenoble) Raw frequency noise Decorrelated noise At 80mK ( TcDC/11) still very sensitive to base T (e.g. 1kHz / mK !) A. Monfardini, IAP 26/06/2012
SRON 1 Credit: A. Barishev, J. Baselmans, A. Endo, L. Ferrari, S. Yates A. Monfardini, IAP 26/06/2012
SRON 2 Credit: A. Barishev, J. Baselmans, A. Endo, L. Ferrari, S. Yates A. Monfardini, IAP 26/06/2012
Electronics (example) A. Monfardini, IAP 26/06/2012
NIKEL v1: the future NIKA read-out Power consumption : negligeable at < 4 K 10 W/ch. at 4 K 100 mW/ch. at 300 K No constrains of power for NIKA. Not optimised at all. NIKEL board v1 (2012). 500 MHz, 400 channels (ADC 12 bits, DAC 16 bits) For details see:O. Bourrion et al., Journ. of Instrum. 6, Issue 06, 6012 (2011) O. Bourrion et al., in press, arXiv:1204.1415 (2012) A. Monfardini, IAP 26/06/2012
A quite fundamental problem:the electrical cross-talk A. Monfardini, IAP 26/06/2012
FULL ARRAY (36 PIXELS) SIMULATION Resonators electrical cross-talk Mainly applies to Lumped Element KIDs A. Monfardini, IAP 26/06/2012
Cross-talk hints • Best candidate : • inductive and/or capacitive • coupling between resonators • Testing : • Feedline impedance • New meanders • GND plane influence • Trenches .. A. Monfardini, IAP 26/06/2012
KIDs environmentalneeds A. Monfardini, IAP 26/06/2012
Materials and Environment • Substrates: • Sapphire. At the very beginning it seemed a must to suppress phae noise. • Now demonstrated it’s not necessary. • Silicon. OK if not oxidated and clean dielectric/metal interface. • Superconducting films: • Aluminium (thin, <40nm). Low-frequency cut-off around 100GHz. • TiN. Still tricky and not fully understood. But potential lower f and NEP. • ..... to be studied ... lots of options • Magnetic environment: sensitive (resonances shifting). Much less than SQUIDs, • but more than MIS. Need classical screening (e.g. high- + superconductor). • Temperature environment: much less sensitive than a bolometer. • Optimal base T (e.g. for 150GHz, Al films): 150 mK or lower • Optimal base T (e.g. for 90GHz, TiN films): 100 mK or lower. • Vibrations environment: much less sensitive than a bolometer. • Cosmic hits: fundamentally less sensitive than bolometers (see later). How • better it is in practice still to be demonstrated (e.g. making resonators on the • same suspended structures used for PACS.. CEA-LETI getting involved). A. Monfardini, IAP 26/06/2012
Cosmics Hits A. Monfardini, IAP 26/06/2012
Cosmics HFI Credit: Andrea Catalano – LPSC Grenoble A. Monfardini, IAP 26/06/2012
LEKIDs under cosmic and x-ray irradiation First ever « cosmic hit movie » (NIKA test array) L. Swenson et al., Applied Physics Letters, 96, Issue 26, id. 263511 (2010) Single 6 keV x-ray photon observed on 11 pixels Dedicated 16 pixels LEKIDs array A. Cruciani et al., LTD-14 A. Monfardini, IAP 26/06/2012
ph >> qp Time (s) Over-gap phonons propagation • Propagation speed: 6-9 mm/s • in < 1 s the « wave » reaches closest pixels • in 10 s a big (e.g. 10cm) array is filled • for t > 10 s , phonons decay to thermal and leaks to the housing. At the same time, a part (1-10%) of the energy goes into quasi-particles and produces a signal. After t0+10s equilibrium between phonons decay/leak (green) ph and quasi-particles lifetime (blue) qp. Depending on technology details one effet might dominate and determine the pulse lenght. D.C.Moore et al., APL 100, Issue 23, id. 232601(2012) A. Monfardini, IAP 26/06/2012
Summary: KIDs and Cosmics BASE ASSUMPTION IN ANY CASE SUSPENDED STRUCTURES ARE NEEDED A SMALL LIST OF POINTS (in favour) TO REMEMBER: • suspended structure is for cosmics ONLY. Not needed for sensitivity. • KIDs are relatively fast. Response typically around 0.1ms; maximum not • exceeding 1ms for very low background applications and pure metals. • KIDs are not sensitive (very little in fact) to thermal phonons. Only • high-energy (T > Tc) phonons can produce a signal. • 4) poor efficiency of energy transfer from phonons to quasi-particles. • For a solid wafer only 1-10% of the deposited energy goes into measurable • signal. A. Monfardini, IAP 26/06/2012
THANKS A. Monfardini, IAP 26/06/2012