Current-biased Kinetic Inductance Detector Research Articles

Neutron detection using a current biased kinetic inductance detector

We demonstrate neutron detection using a solid state superconducting current biased kinetic inductance detector (CB-KID), which consists of a superconducting Nb meander line of 1 μm width and 40 nm thickness. 10B-enriched neutron absorber layer of 150 nm thickness is placed on top of the CB-KID. Our neutron detectors are able to operate in a wide superconducting region in the bias current–temperature diagram. This is in sharp contrast with our preceding current-biased transition edge detector, which can operate only in a narrow range just below the superconducting critical temperature. The full width at half maximum of the signals remains of the order of a few tens of ns, which confirms the high speed operation of our detectors.

20 ps Pulsed Laser Irradiation to Current-Biased Kinetic Inductance Detector Made of Nb Nanowires

A current-biased kinetic inductance detector (CB-KID) is a new type of superconducting detector and senses a change in kinetic inductance in the superconducting nanowire biased by weak dc current I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</sub> . Kinetic inductance depends on the density of Cooper pairs. Therefore, when Cooper pairs are broken by local energy dissipation, a change in kinetic inductance ΔLk can be obtained by monitoring a voltage V across the CB-KID sensor. The CB-KID has a wide operating temperature regime in the superconducting state whereas a current-biased transition edge detector senses a change in resistance at the superconductive transition edge and operates only at near vicinity of Tc. The confirmation for the validity of the CB-KID idea was preceded by using an MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> CB-KID meanderline detector. We extended this CB-KID method to a conventional Nb nanowire. We consider that our Nb-based CB-KID has versatile potentials in the various future applications. It is for the first time that the Nb-based CBKID operates at 4 K and has a capability of submicrometer position resolution.

Toward Neutron Radiography Using Two Arrays of Nb-Based Current-Biased Kinetic Inductance Detectors With &lt;sup&gt;10&lt;/sup&gt;B Converter Sandwiched In-Between

A superconducting nanowire detector with a <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B conversion layer is useful for sensing a single neutron at a high operation rate. We use <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> Li ion and <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> He ion emitted as two independent heat sources in opposite direction, which are associated with nuclear reaction <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B(n, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> He) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> Li to identify the XV position of neutron arrival. We probe a change rate in the kinetic inductance L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</sub> originating from kinetic inertia of the Cooper pairs. Our detector is different from a well-known microwave kinetic inductance detector and, hence, is named as a current-biased kinetic inductance detector. We use two sets of meanderlines made of Nb nanowires with superconducting readout taps to monitor local signals. In between the X meander and the V meander, we sandwiched a <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B layer acting as a neutron conversion layer to two charged particles. We succeeded in observing signal induced by nuclear reaction. We plan to build a megapixel neutron imager by coupling 10-bit linear position-sensitive arrays with single-flux quantum circuits to read (X,V) position of neutron arrival in the future.

24pCJ-2 電流バイアス運動インダクタンス(CB-KID)法によるNb超伝導中性子検出器の開発V

24pCJ-2 電流バイアス運動インダクタンス(CB-KID)法によるNb超伝導中性子検出器の開発V

Toward Mega-pixel Neutron Imager Using Current-Biased Kinetic Inductance Detectors of Nb Nanowires with $$^{10}$$ 10 B Converter

We present not the results but the idea of a superconducting nanowire detector with \(^{10}\)B conversion layer for sensing a single neutron. We use \(^{7}\)Li ion and \(^{4}\)He ion emitted as two independent heat sources, which appear in opposite direction associated with nuclear reaction \(^{10}\)B(n,\(^{4}\)He)\(^{7}\)Li. We probe a change in the kinetic inductance \(L_\mathrm{k}\) coming from inertia of the Cooper pairs. Our detector is different from a conventional kinetic inductance detector (KID), but is named as a current-biased KID. We use two sets of Nb nanowires with superconducting readout taps to monitor the local signal. In between the X meander and the Y meander, we inserted a \(^{10}\)B layer acting as a conversion layer from neutrons to charged particles. We plan to fabricate a mega-pixel neutron imager by coupling 10 bit linear position-sensitive arrays along the X and Y directions with the single flux quantum readout circuits.

Four-Channel Current-Biased Kinetic Inductance Detectors Using MgB $$_2$$ 2 Nanowires for Sensing Pulsed Laser Irradiation

We recently proposed the idea of a novel sort of superconducting detector, i.e., a current-biased kinetic inductance detector (CB-KID). This detector is different from a current-biased transition edge detector studied previously, and is able to sense a change in kinetic inductance $$L_k$$ given by $$L_{k} = \Lambda _{k}l/S = m_{s}l/n_{s}{q_{s}}^{2}S$$ ( $$\Lambda _{k}$$ ; kinetic inductivity, $$m_s$$ ; mass of Cooper pair, $$n_s$$ ; density of Cooper pairs, $$q_s$$ ; charge of Cooper pair, $$l$$ ; length of device, $$S$$ ; cross sectional area) under a constant dc bias current $$I_b$$ . In the present work, we first extend this idea to construct a multi-channel CB-KIDs array made of 200-nm-thick MgB $$_2$$ thin-film meanderline with 3- $$\upmu $$ m thin wire. We succeeded in observing clear signals for imaging from the four-channel CB-KIDs at 4 K by irradiating focused pulsed laser. A scanning laser spot can be achieved by an XYZ piezo-driven stage and an optical fiber with an aspheric focused lens. We can see typical signals from all 4 channels at 4 K, and obtain the positional dependence of the signal as the contour in XY plane. Our CB-KIDs can be used as neutron detectors by utilizing energy released from a nuclear reaction between $$^{10}$$ B and cold neutron.

Current-Biased Kinetic Inductance Detector Using $ \hbox{MgB}_{2}$ Nanowires for Detecting Neutrons

We propose a current-biased kinetic inductance detector (CB-KID). This detector senses a change in kinetic inductance under a dc bias current, in contrast to a current-biased transition edge detector, reported previously, which probes the transient change in the bias current at the transition edge. Our CB-KID consists of a 200-nm-thick thin-film meander line with 3- wire. It is operated at 4 K. A scanning laser spot can be achieved by an XYZ piezo-driven stage and an optical fiber with an aspheric focused lens. We succeeded in observing a signal image in the contour at 4 K. The magnitude of the signal should be proportional to the number of quasi-particles excited by the laser. Because our CB-KID has a typical signal of 3-ns pulse width and can operate at 4 K, it will be possible to assemble a large-scale array of neutron detectors with single flux quantum readout circuits.