Kinetic inductance detector
Encyclopedia
The kinetic inductance detector (KID) — also known as a microwave kinetic inductance detector (MKID) — is a type of superconducting
photon
detector first developed by scientists at the California Institute of Technology
and the Jet Propulsion Laboratory
in 2003. These devices operate at cryogenic
temperatures, typically below 1 kelvin
. They are being developed for high-sensitivity astronomical
detection for frequencies ranging from the far-infrared
to X-rays.
material break Cooper pairs and create excess quasiparticles. The kinetic inductance
of the superconducting strip is inversely proportional to the density of Cooper pairs, and thus the kinetic inductance increases upon photon absorption. This inductance is combined with a capacitor
to form a microwave
resonator
whose resonant frequency changes with the absorption of photons. This resonator-based readout is useful for developing large-format detector arrays, as each KID can be addressed by a single microwave tone and many detectors can be measured using a single broadband microwave channel, a technique known as frequency-division multiplexing
.
applications, including millimeter and submillimeter wavelength detection
at the Caltech Submillimeter Observatory
, the Atacama Pathfinder Experiment
(APEX) on the Llano de Chajnantor Observatory
, and the IRAM 30-m
telescope. They are also being developed for optical and near-infrared detection at the Palomar Observatory
.
Superconductivity
Superconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum...
photon
Photon
In physics, a photon is an elementary particle, the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force...
detector first developed by scientists at the California Institute of Technology
California Institute of Technology
The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...
and the Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...
in 2003. These devices operate at cryogenic
Cryogenic particle detectors
Cryogenic particle detectors operate at very low temperature, typically only a few degrees above absolute zero. These sensors interact with an energetic elementary particle and deliver a signal which can be related to the type of particle and the nature of the interaction...
temperatures, typically below 1 kelvin
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
. They are being developed for high-sensitivity astronomical
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
detection for frequencies ranging from the far-infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
to X-rays.
Principle of operation
Photons incident on a strip of superconductingSuperconductivity
Superconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum...
material break Cooper pairs and create excess quasiparticles. The kinetic inductance
Kinetic inductance
Kinetic inductance is the manifestation of the inertial mass of mobile charge carriers in alternating electric fields as an equivalent series inductance. Kinetic inductance is observed in high carrier mobility conductors Kinetic inductance is the manifestation of the inertial mass of mobile charge...
of the superconducting strip is inversely proportional to the density of Cooper pairs, and thus the kinetic inductance increases upon photon absorption. This inductance is combined with a capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
to form a microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
resonator
Resonator
A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical...
whose resonant frequency changes with the absorption of photons. This resonator-based readout is useful for developing large-format detector arrays, as each KID can be addressed by a single microwave tone and many detectors can be measured using a single broadband microwave channel, a technique known as frequency-division multiplexing
Multiplexing
The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...
.
Applications
KIDs are being developed for a range of astronomyAstronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
applications, including millimeter and submillimeter wavelength detection
at the Caltech Submillimeter Observatory
Caltech Submillimeter Observatory
The Caltech Submillimeter Observatory is a diameter submillimeter wavelength telescope situated alongside the James Clerk Maxwell Telescope at Mauna Kea Observatory. It is engaged in submillimeter astronomy, of the terahertz radiation band.The CSO and JCMT were combined to form the first...
, the Atacama Pathfinder Experiment
Atacama Pathfinder Experiment
The Atacama Pathfinder Experiment is a radio telescope located at 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert, in northern Chile, 50 kilometers to the east of San Pedro de Atacama. The main dish has a diameter of 12 meters and consists of 264...
(APEX) on the Llano de Chajnantor Observatory
Llano de Chajnantor Observatory
Llano de Chajnantor Observatory is an astronomical observatory located at an altitude of 5,104 m in the Chilean Atacama desert, 50 kilometers to the east of San Pedro de Atacama. It is a very dry site - inhospitable to humans - but an excellent site for submillimetre astronomy...
, and the IRAM 30-m
IRAM 30-m
The IRAM 30-m Millimeter Radio Telescope is a radio telescope for astronomical observations in the millimeter range of wavelengths, operated by the Institute for Radio Astronomy in the Millimeter Range ) and located on the Sierra Nevada, in Spain, close to the Pico Veleta peak. It is the largest...
telescope. They are also being developed for optical and near-infrared detection at the Palomar Observatory
Palomar Observatory
Palomar Observatory is a privately owned observatory located in San Diego County, California, southeast of Pasadena's Mount Wilson Observatory, in the Palomar Mountain Range. At approximately elevation, it is owned and operated by the California Institute of Technology...
.