Diffraction tomography is an imaging technique used to reconstruct the internal structure of an object from scattered waves, typically electromagnetic waves (like light or X-rays) or acoustic waves (like sound). The method is closely associated with the principles of diffraction, which describes how waves bend around obstacles and spread out after passing through narrow openings. ### Key Concepts: 1. **Scattered Waves**: When waves encounter an object, they can scatter in various directions depending on the object's properties.

In particle physics, a "soft photon" refers to a type of photon that has relatively low energy and, as a result, long wavelength. The term is often used in the context of quantum electrodynamics (QED) and scattering processes. Soft photons are particularly relevant in discussions about radiation emitted during high-energy processes, such as the collisions of charged particles.

A cryogenic storage dewar, commonly referred to simply as a "dewar," is a specialized container designed for the storage and transport of cryogenic liquids, such as liquid nitrogen, liquid helium, or other gases that have been cooled to extremely low temperatures. The design of a dewar is intended to minimize heat transfer from the environment into the stored cryogenic substance, keeping it at very low temperatures for extended periods.

Yeti Holdings, often referred to simply as YETI, is an American company known for producing premium outdoor and lifestyle products, particularly coolers, drinkware, and other gear designed for outdoor activities like camping, fishing, and hiking. The brand is recognized for its durable, high-performance products that cater to outdoor enthusiasts.

A molecular drag pump is a type of vacuum pump designed to achieve very low pressures (high vacuum conditions) by utilizing molecular flow principles. Instead of relying on mechanical means to compress gases, it operates based on the interactions between gas molecules and a moving surface. ### Key Principles of Molecular Drag Pumps: 1. **Molecular Flow**: At extremely low pressures, the mean free path of gas molecules is much larger than the dimensions of the pump.

A vacuum ejector, also known as a vacuum pump ejector or venturi vacuum pump, is a device that generates a vacuum using the principle of fluid dynamics. It operates on the Venturi effect, where a fluid (usually air or water) is passed through a nozzle that narrows, causing a drop in pressure and an increase in velocity. This low pressure area can be used to create a vacuum.

Air-free techniques refer to a set of methods used in chemistry and materials science to handle sensitive substances without exposure to air, particularly oxygen and moisture. These techniques are essential for working with air-sensitive compounds, such as certain organometallics, transition metal complexes, and organosilicon compounds, which may degrade or react unfavorably when exposed to atmospheric conditions.

Ramsay grease is a term used in the context of grease used in mechanical or industrial applications, particularly in relation to lubrication systems. However, it could also refer to a specific formulation or brand of grease used for particular applications, although specific references to "Ramsay grease" aren't widely recognized in standard lubrication terminology. If you have a more specific context or application in mind (like automotive, marine, industrial machinery, etc.

A vacuum airship, also known as a vacuum balloon, is a type of lighter-than-air craft that achieves buoyancy by having a vacuum inside its structure, rather than using a gas that is lighter than air, such as helium or hydrogen. The concept relies on creating a sealed envelope that can withstand atmospheric pressure from the outside while maintaining a lower pressure inside, effectively reducing the overall density of the airship.

Vacuum grease is a specialized, high-viscosity lubricant designed for use in vacuum systems and applications where a low-pressure environment is essential. It is typically made from a combination of silicone, hydrocarbon, or other synthetic polymers, and is meant to create a seal that prevents the ingress of air and moisture, ensuring that vacuum levels are maintained.

Neon lighting refers to a lighting technology that uses glass tubes filled with inert gases, primarily neon, to produce a bright and colorful glow when an electrical current is applied. This type of lighting is often used for creating signs, decorative displays, and artistic installations. Here’s a more detailed breakdown: ### How Neon Lighting Works: 1. **Component Setup**: Neon lights consist of glass tubes that are bent into various shapes.

A Backward-Wave Oscillator (BWO) is a microwave device that generates high-frequency electromagnetic waves, typically in the microwave range. The BWO operates based on the principle of backward wave propagation, which involves electrons interacting with a backward wave in a slow-wave structure. ### Key Concepts: 1. **Backward Waves**: In a BWO, the wave propagates in the opposite direction to the flow of electrons. This unique interaction is vital for the oscillator's operation.

The Barkhausen–Kurz tube is a type of vacuum tube that was developed for the generation of high-frequency oscillations. It is named after its inventors, Heinrich Barkhausen and Karl Kurz, who contributed to its development in the early 20th century. The Barkhausen–Kurz tube is essentially a form of oscillator that utilizes the principles of electron dynamics in a vacuum environment. The design typically involves a cathode that emits electrons, which are then accelerated toward an anode.

The British Valve Association (BVA) is an industry organization in the United Kingdom that represents manufacturers and suppliers of valves, actuators, and related products used in fluid control applications. The BVA aims to promote the interests of its members, enhance the industry standards, and provide a platform for collaboration and knowledge sharing among its members and stakeholders.

The term "double diode triode" is not standard in electronics, but it seems to refer to a vacuum tube or thermionic device that combines the functions of two diodes and a triode in a single envelope. Here’s a breakdown of the components: 1. **Diodes**: A diode is a two-terminal electronic component that allows current to flow in one direction only. In a vacuum tube context, a diode consists of two electrodes—a cathode and an anode.

A grid-leak detector is a type of electronic circuit used primarily in radio and audio equipment to detect small currents, typically resulting from a leakage path in high-impedance circuits, such as those found in vacuum tube amplifiers. These detectors can help identify problems such as capacitor leaks or other issues that might cause unwanted current flow. The term "grid-leak" originates from vacuum tube technology, where the control element of a vacuum tube is referred to as the "grid.

An image intensifier is an optical device used to enhance the visibility of low-light images. It works by amplifying the light from a scene, allowing images to be visible in conditions where normal light would be insufficient for the human eye or standard cameras. Here’s how it typically works: 1. **Photon Capture**: The image intensifier has a photocathode, which is a surface that converts incoming photons (light particles) into electrons.

A Krytron is a type of high-speed switch used in electronics that operates on the principle of gas discharge. Specifically, it is a gas-filled tube that can quickly switch between conducting and non-conducting states when a small voltage is applied to its control electrodes. Krytrons are known for their ability to operate at extremely high speeds, making them suitable for applications such as pulse circuits, radar systems, and other high-frequency electronic devices.

The Mullard 5-10 is a well-known transistor amplifier design that was developed in the 1960s by the British electronics company Mullard. It is particularly popular among audio enthusiasts and hobbyists for its simplicity and good sound quality. The name "5-10" refers to its design using a combination of five stages (input, tone control, and power amplification) and ten transistors in total.

A phototube, often referred to as a photoelectric tube or photomultiplier tube (PMT), is a type of electronic device that detects and measures light. It operates based on the photoelectric effect, where photons striking the surface of a photosensitive material (such as a photocathode) release electrons.