physics

Kinetic inductance detector

Kinetic inductance detector is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Kinetic inductance detector rather than just read about it. In short: The kinetic inductance detector (KID) — also known as a microwave kinetic inductance detector (MKID) — is a type of superconducting photon detector capable of counting single photons whilst simultaneously measuring their energy and arrival time to high precision. They were first developed by scientists at the California Institute of Technology and the Jet Propulsion Laboratory in 2003.

Key takeaways

Kinetic inductance detector belongs to physics; place it in that map before memorising details.
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Connect Kinetic inductance detector to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kinetic inductance detector from memory before moving on to harder problems.

Reference excerpt

The kinetic inductance detector (KID) — also known as a microwave kinetic inductance detector (MKID) — is a type of superconducting photon detector capable of counting single photons whilst simultaneously measuring their energy and arrival time to high precision. They were 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. KIDs are notable as photosensors that can differentiate incident photon energies, though they are limited by quantum uncertainty to an approximate spectral resolution of R≈100.

Principle of operation Photons incident on a strip of superconducting 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. This shift in resonant frequency also causes a phase shift proportional to the incident photon energy which is the primary way in which detections are identified.

Applications KIDs are being developed for a range of astronomy applications, including millimeter and submillimeter wavelength detection at the Caltech Submillimeter Observatory, the Atacama Pathfinder Experiment (APEX) on the Llano de Chajnantor Observatory, the CCAT Observatory, the Large Millimeter Telescope, and the IRAM 30-m telescope. They are also being developed for optical and near-infrared detection at the Palomar Observatory. KIDs have also flown on two balloon-borne telescopes, OLIMPO in 2018 and BLAST-TNG in 2020. They are also foreseen for the spectrometers of the planned PRobe far-Infrared Mission for Astrophysics (PRIMA) telescope, which NASA selected as one of two potential future space telescopes. They are also the basis for a new class of multi object high resolution spectrometer which would replace the second dispersive element of an echelle spectrograph and the photosensor with a linear KID array. KIDs have also gained popularity as a more compact, lower cost, and less complex alternative to transition edge sensors.

See also Kinetic inductance Cryogenic particle detectors

References

External links SRON website on kinetic inductance detectors Research group of Prof. B. Mazin at UC Santa Barbara Archived 2010-12-03 at the Wayback Machine YouTube video on kinetic inductance from MIT Champlin, K.S.; Armstrong, D.B.; Gunderson, P.D. (1964). "Charge carrier inertia in semiconductors". Proceedings of the IEEE. 52 (6). Institute of Electrical and Electronics Engineers (IEEE): 677–685. Bibcode:1964IEEEP..52..677C. doi:10.1109/proc.1964.3049. ISSN 0018-9219.

Illustrations

Worked examples

Example 1 — a first encounter with Kinetic inductance detector

Start with the simplest possible case. Write down what Kinetic inductance detector claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Kinetic inductance detector before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Kinetic inductance detector ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Kinetic inductance detector

In research: Kinetic inductance detector appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Kinetic inductance detector in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Kinetic inductance detector is common in secondary-school and first-year university syllabi. It links to neighbouring topics Particle detectors, Radiometry, Sensors, so understanding it makes those chapters shorter.
In everyday life: Look for Kinetic inductance detector outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Kinetic inductance detector in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kinetic inductance detector means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
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Frequently asked questions

What is Kinetic inductance detector in simple terms?

Why does Kinetic inductance detector matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Kinetic inductance detector?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Kinetic inductance detector.