Related Experiment Video
Updated: Jan 28, 2026
07:42
AC-DC Electropenetrography for the Study of Probing and Ingestion Behaviors of Culex tarsalis Mosquitoes on Human Hands
Published on: November 29, 2024
802
Nanokelvin DC and AC Meissner-transition-edge temperature detectors.
S I Woods1, A C Carter2, T M Jung2
1Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
The Review of Scientific Instruments
|March 6, 2019
Summary
Researchers enhanced the Meissner transition edge sensor (TES) for high-resolution thermometry. New AC mode offers lower magnetic noise and improved sensitivity for cryogenic applications.
Area of Science:
- Cryogenics
- Superconductivity
- Thermometry
Background:
- The Meissner-TES is a novel cryogenic thermometer utilizing superconducting magnetic transitions.
- Previous iterations required signal-to-noise ratio improvements for DC sensing.
Purpose of the Study:
- To enhance the signal-to-noise ratio (SNR) of the Meissner-TES for DC sensing.
- To develop a new AC mode for improved low-noise cryogenic thermometry.
- To demonstrate in situ tuning capabilities over a wide temperature range.
Main Methods:
- Improved DC sensing techniques, achieving a 30x SNR increase.
- Developed a novel AC mode employing oscillating magnetic fields and lock-in detection.
- In situ tuning of the thermometer using persistent magnetic fields across a broad temperature range.
Main Results:
- Achieved DC mode sensitivity better than 1 nK with 100 s averaging.
- AC mode demonstrated sensitivity better than 120 nK at ~14 nT with 100 s averaging.
- The AC mode exhibits significantly lower magnetic noise compared to the DC mode.
Conclusions:
- The enhanced Meissner-TES offers superior performance for high-resolution cryogenic thermometry.
- The new AC mode provides a low-noise alternative for sensitive magnetic field measurements.
- Applications include precise temperature control, infrared sensing, and fundamental physics studies.
Related Concept Videos
02:31Phase Transitions
23.1K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
23.1K
01:19DC Generator
2.0K
An alternator converts mechanical energy into electrical energy that varies sinusoidally, resulting in AC current. Meanwhile, a DC generator converts mechanical energy into electrical energy, which are DC pulses with the same polarity. The construction of a DC generator is similar to that of an alternator, except that the pair of slip rings is replaced by a single split ring, also called a commutator. The commutator functions like a periodic rotary switch; it changes the contacts with the...
2.0K
01:20AC Sources
4.1K
Direct current is a flow of electric charge in only one direction and has a steady state of constant voltage in the circuit. Rectifiers, batteries, commutator-equipped generators, and fuel cells are some examples of devices that generate direct current. Nowadays, most applications use a time-varying voltage source. Alternating current is a flow of electric charge that periodically reverses direction. An alternating current is produced by an alternating emf that is generated in a power plant. If...
4.1K
01:21DC Battery
1.3K
A conductor needs to be a component of a path that creates a closed loop or full circuit to have a continuous current flowing through it. A current starts to flow if an electric field is created inside an isolated conductor that is not part of a full circuit. The conductor quickly develops a net positive charge at one end and a net negative charge at the other. These charges generate an electric field opposite the direction of the applied electric field, which reduces the current. Eventually,...
1.3K
02:58Properties of Transition Metals
29.7K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
29.7K
01:58Cooperative Allosteric Transitions
8.7K
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
8.7K