Rivelatori a induttanza cinetica (KIDs):sensori per la banda mm/FIRideali per applicazioni spaziali
M.G. Castellano3, I. Colantoni1, A. Coppolecchia1, A. Cruciani1,2, A. D’Addabbo4, P. de Bernardis1,2,
S. Masi1,2, A. Paiella1,2, G. Presta1
1 ‐ Dipartimento di Fisica, Università di Roma Sapienza, Roma, Italy2 ‐ INFN, Sezione di Roma 1, Roma, Italy3 ‐ Istituto di fotonica e nanotecnologie (CNR), Roma, Italy4 ‐ Laboratori Nazionali del Gran Sasso (INFN), L’ Aquila, Italy
mm/FIR band ( 100 GHz – 10 THz )• The development of panoramic (many‐pixel) detectors in thisband is important because:
• in the mm/submm range there are important spectral signatures of many molecules and materials.
• This is important in many fields, from remote sensing to astronomy.• Several materials become transparent, allowing for non‐destructive internal inspections.
• Applications (from the literature):• Astronomy: Study of interstellar medium• Cosmology: Study of the Cosmic Microwave Background• Physics: detection of rare events (CUORE)• Medical: Imaging devices to improve detection of some skin cancers• Art/Forensic: Non‐destructive investigation of internal paint layers• Industrial: Detection of hidden objects in manufacturing • Security: Detection of hidden objects in security screening• … and many more
350 GHz VIS Thermal IR
arXiv:1511.06011: A passive THz video camera based on lumped element kinetic inductance detectors
Linear array ofLumpedElementsKineticInductanceDetectors (KID)
cryostat
Optics & scanner
arXiv:1511.06011: A passive THz video camera based on lumped element kinetic inductance detectors
100 GHz – 10 THz : Three detection technologies• Coherent (consolidated, limited to the low‐end of the band)• Transition‐Edge Superconducting bolometers (consolidated)• Kinetic Inductance Detectors (emerging)
meV photons meV photons meV photons
antenna
probe
amplifier
rectifier
antenna
absorber
SuperConductingthermistor
antenna
SuperConductingresonator
W ‐> V
W ‐> R
W ‐> f
Coherent
TES
KID
MMIC LNAs (L‐band to W‐band)NRAO
T operation: 10Kf < 200 GHzFor large arrays:‐ Each pixel requires
one amplifier.‐ Very Expensive‐ Power hungry
Coherent TES
T operation: 0.1KOK at all f. =1 msFor large arrays:‐ Can be replicated in
thousands on the same wafer at negligible cost
‐ Complex production processing
‐ Multiplexing possible butcomplex
‐ Spider‐web absorber veryfragile
KID
T operation: 0.1Kf>60 GHz. =0.01 msFor large arrays:‐ Can be replicated in
thousands on the samewafer at negligible cost
‐ Easier production processing
‐ Easy Multiplexing‐ Robust (no suspended
parts)
The CPs have zero DC resistance, but the reactance is non‐zero and has two distinctcontribution kinetic and magnetic L.
KIDs working principle:
In a superconductor below Tc , electrons can bind to form CPs with binding energy E=2=3.5*kbTc .
The total conductivity of the material can be estimated using the two‐fluid model
CPs
QPs
The values of ss and sn depend on the densities of QPs and CPs. By measuring them, we can get information on nqp .
Js Jn
‐is2nCP ‐is2nQP s1nQP
A better estimate of ss and sn is obtained using the Mattis Bardeen integrals:
A better theory...
Note that:
• Rs decreases exponentially
• Xs becomes constant
• Xs/ Rs grows exponentially
D. C. Mattis and J. Bardeen, in Phys Rev 111 (1958)
How do we actually measure the incoming radiation?
n′CP< nCP
QPs
CPs
• Suppose a photon hits the detector
• If its energy is high enough (h> E) it can break CPs
• The density of CPs therefore changes
• This leads to a variation of Lkin
The same effect can be accomplished by increasing the temperature of the superconductor
The readout is accomplished by monitoring the phase of the transmitted signal
Lf 10
How can we measure the small variations of Lk?The superconductor can be inserted in a resonating circuit with extremely high Q, since:
ss RXQ
The resonator is extremely simple to do, and consists of a shorted length of superconducting line capacitevely coupled to the feedline l/4 resonator
Cc
RQPLkin
Lmag
Cl
KIDs are intrinsicallymultiplexable:
• Unitary transmission off resonance
• Q values very large (104 ‐106)
Multiplexing
Each resonator acts at the same time as detector and filter
Cnc
RnQPLnkin
Lnmag
Cnl
C1c
R1QPL1kin
L1mag
C1l
C2c
R2QPL2kin
L2mag
C2l
RF carrier (f 1 + f 2 + ... + f n )
Pixel 1, f 1 Pixel 2, f 2 Pixel n, f n
Two cables and one amplifier needed in the cryostat.
M. Calvo et al. Development of Kinetic Inductance Detectors for Cosmic Microwave Background experiments, Experimental Astronomy (2010) 28: 185–194
A. Paiella et al. [arXiv:1601.01466].
Cryogenic system overview
SCN‐CN coax
VNA / IQ mixers
2xDC block2xDC block2x10dB atten
1xDC block1xDC block1x10dB atten
KID
300K
30K
2K
300mK
SCN‐CN coax
SS‐SS coax
warm amplifier
cold amplifier
KIDs readout system
0.3K 2K
Re(S21)
Im(S21)
DAQ
fsynt
fsynt
PC
DAC
ADC
fsynt
fsynt ± f0 , fsynt ± f1...
f0, f1...
f0, f1...
fsynt ± f0 , fsynt ± f1...0.3K 2K
Re(S21)
Im(S21)
PC
DAC
ADC
fsynt
fsynt
f0, f1...
f0, f1...
fsynt ± f0 , fsynt ± f1...
KIDs in space ?• Very robust (single wafer, no machining, no membranes, no spider‐web)
• Fast: • Allow for fast scanning of the sky• Cosmic ray events last for tens of s and can be flagged and removed from the datastream, resulting in a negligible data loss
• Low‐power readout: a single FPGA can read 1000• Activities (space‐oriented):
• Space‐KIDs – FP7 (laboratory)• ESA‐ITT 1‐7393 (focal plane arrays)• Tests on stratospheric balloons (Adv.BLASTpol, Plan‐B, OLIMPO)
• ASI proposal KIDS (Kinetic Inductance Detectors in Space), Bando DC‐EOS‐2014‐309