Radiation detection equipment

At the conclusion of this station, you should be familiar with  

The use of the various types of radiation detection equipment available 

The use of a low range Beta-Gamma or Alpha radiation detector 

Radiation detection equipment operates on the principle that the radiation interacts with gases or crystal within the detector to produce ionization that the instrument electronically converts to a reading. Instruments normally detect only certain types and certain levels of radiation. Most of these devices are not precision instruments, and the error rate can he up to 20%. For this reason, conservative estimates of exposure and dose should be used to ensure that emergency limits are not exceeded. 

Low-range instruments (these normally have a handheld probe) usually detect alpha or beta particles and gamma radiation. These instruments are used to detect contamination (qualitative) and are not useful to measure higher radiation readings. 

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Aloise, Gene, Combating Nuclear Smuggling Efforts to Deploy Radiation Detection Equipment in the United States and Other Countries, June 21, 2005, GAO-05-840T. 

For this reason, NCRP recommends that emergency response personnel and first response vehicles should be equipped with radiation detection equipment to alert them for a radiologically compromised environment. Furthermore, this equipment should be designed to alert the responders when unacceptable ambient dose rates or dose limits are reached. Responders should wear appropriate personal protective equipment (e.g., chemical safety suits, respirators). 

Radiation Detection Equipment for Monitoring Personnel and Packages... 

Figure 1. Block diagram of cool flame radiation detection equipment...

F. The report of an area survey should include the name of survey team members, the date and time that the survey was performed, and the type of radiation detection equipment used in the survey. It should also contain the calibration date, and other remarks that may be helpful in evaluating the attached survey plot. 

Cs-137 is used in small amounts for calibration of radiation-detection equipment, such as Geigei -Mueller counters. In larger amounts, Cs-137 is used in medical radiation therapy devices for treating cancer in many industrial gauges that detect the flow of liquid through pipes and in other industrial devices to measure the thickness of materials, such as paper, photographic film, or sheets of metal. 

Theory and Equipment. The basic principle behind nuclear medical imaging is that a radiopharmaceutical can be introduced into the body which emits radiation detectable outside of the body. Radiopharmaceuticals are biologically active and have a short half-life (Si/q)- The detectable radiation... 

In order to protect against these radioactive materials being brought on-site, a facility may set up monitoring sites outfitted with radiation detection instrumentation at entrances to the facility. Depending on the specific types of equipment chosen, this equipment would detect radiation emitted from people, packages, or other objects transported through an entrance. 

One of the primary differences between the different types of detection equipment is the means by which the equipment reads the radiation. Radiation may be detected either by direct measurement or through sampling. 

Typical irradiation facilities consist of a process chamber containing the radiation source, some sort of conveyor systems to transport products inside and outside the shielding walls, and sophisticated control and safety systems. Irradiation facilities are built with several layers of redundant protection to detect equipment malfunctions and protect employees from accidental exposure. Technical details depend on the type of irradiation. Typical processing parameters are compared in Table 2 [7]. 

Method 4. Improving the specificity of the detection equipment to the type and energy of the emitted radiations. 

Thermal emission is based on measuring the fundamental absorption bands of glucose at 10pm, using the body s naturally emitted infrared radiation as the source. The detection equipment is similar to that used for infrared absorption spectroscopy. Malchoff et al.82 reported the evaluation of a prototype that measures the infrared emission from the tympanic membrane. 

With minor exceptions, the samples handled in a radiochemical laboratory are eventually measured with radiation detection instruments. The types of counting equipment in the counting room depend primarily on the scope and purpose of the radioanalytical chemistry laboratory mission. Common detectors of this type are listed in Table 2.1. 

A. The success of medical support effort depends to a great degree on the adequacy of prewar logistical planning and preparation. Logistical plans should provide not only for medical supplies and equipment but also general supplies, food, clothing, water purification apparatus, radiation detection and measurement instruments, communications equipment, and modes of transportation. 

Thallium sulfate used to be used to kill ants and rats, but the extremely high toxicity levels of T1 compounds are now well recognized and aU Tl-containing species must be treated with caution. The world production of thalhum (15 000 kg in 2001) is far less than that of galhum (Figure 12.3) and indium. Important uses of T1 are in semiconducting materials in selenium rectifiers, in Tl-activated NaCl and Nal crystals in 7-radiation detectors, and in IR radiation detection and transmission equipment. The radioisotope T1 h = 12.2d) is used for cardiovascular imaging. 

The occupational radiation protection programme, including arrangements for monitoring of workers and the workplace, and the provision and maintenance of personal protective equipment and equipment for radiation detection ... 

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