A liquid scintillation detector is a device used to detect and measure ionizing radiation by using a liquid scintillator, which emits light when radiation interacts with it. The composition typically includes a solvent, such as toluene or xylene, mixed with scintillating solutes like phenyl xylene or PPO (2,5-diphenyloxazole). When radiation passes through the liquid, it excites the scintillating molecules, causing them to emit photons, which are then detected by photomultiplier tubes. This technology is commonly used in applications like radioisotope counting and environmental monitoring.
In the beta-counter or liquid scintillation counter, the sample is dissolved in an organic scintillation solution. Due to the resulting 100% counting geometry and the absence of any detector window, this means that the counter has excellent properties in detecting radionuclides of low activity emitting low energy beta-particles, such as H3 and C14. The light photons from the sample are collected by two photomultipliers in coincidence. This arrangement will reduce the background due to thermal noise and only true scintillation events will be analysed and counted. The main problem in liquid scintillation counting is the varying counting efficiency due to quenching of scintillation events. This process is caused by chemical contamination of the sample and/or a coloured sample. This means that the counting efficiency has to be determined for every sample. Therefore a quality control of the instrument must include a control of the correction methods. Otherwise the QC methods will be the same as for any scintillation counter. The sources needed for QC of a liquid scintillation counter include calibrated sources of H3 and C14 with different counting efficiencies as well as a background sample.
A pressure detector placed in a vessel to measure liquid level uses the principle that the pressure at a specific depth in a liquid is proportional to the height of the liquid above it. By measuring the pressure at the bottom of the vessel, the detector can calculate the liquid level. This method is commonly used in industries such as oil and gas, chemical processing, and wastewater treatment.
Brian W. Fox has written: 'Christie's' -- subject(s): Cancer, Christie Hospital, History, Holt Radium Institute, Hospitals 'Techniques of sample preparation of liquid scintillation counting' -- subject(s): Isoelectric focusing, Liquid scintillation counting
Scintillation is a fluctuation in the amplitude of a target on a radar display. It is closely related to target glint, or wander, an apparent displacement of the target from its mean position. This effect can be caused by a shift of the effective reflection point on the target, but has other causes as well. The fluctuations can be slow (scan-to-scan) or rapid (pulse-to-pulse).It appears especially at seaside level.Scintillation and glint are actually two manifestations of the same phenomenon and are most properly linked to one another in target modeling.hyperpure germanium detector:A variant of the lithium-drifted germanium crystal which uses high-purity germanium, making it possible to store the detector at room temperature rather than liquid nitrogen temperature. Read more: hyperpure-germanium-detector
A liquid is a compound or a mixture; the chemical composition is representative for this liquid.
Phillip L. Howard has written: 'Basic liquid scintillation counting' -- subject(s): Laboratory Diagnosis, Liquid scintillator counting
The composition of liquid air is: 80 % nitrogen, 19 % oxygen 0,9 % argon, 0,1 % minor gases.
The composition of liquid air is: 80 % nitrogen, 19 % oxygen 0,9 % argon, 0,1 % minor gases.
Data from a MSDS:• A survey meter equipped with a G-M pancake or thin-window probe (with window thickness < 0.2 mg/cm2) is effective for detecting Am-241. Detection efficiency is between 5% (end window) and 25% (upper range pancake probe).• A survey meter equipped with a alpha scintillation probe is suitable for detection of the Am-241. Typical efficiency is 25%-35%.• Either a gamma counter or a liquid scintillation counter may be used to detect removable Am-241 contamination on wipe tests smears. The efficiency for a liquid scintillation counter can be 100% for detection of alphas.
A liquid scintillation counter is a device that uses a superheated liquid to detect radioactive particles. These particles interact with the liquid, producing light flashes that can be measured to determine the level of radioactivity.
The ED spectrometer is comprised of a liquid nitrogen (LN2) dewar, Si crystal, and preamplifier. The special Si crystal is mounted at the end of the detector located closest to the specimen. When X-rays strike the Si crystal very small signals are produced. These signals are amplified in the detector and sent on to the analysis electronics in the computer for further processing. The crystal is cooled by a cold finger, an extension of the LN2 dewar. Liquid nitrogen cools and therefore stabilizes the electronic properties of the crystal, improving the measurements of minute X-ray signals.
The chemical composition is different.