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Radiation is a form of energy that is present in our environment and can have harmful effects on living organisms. Radiation threats come from a variety of sources, including nuclear power plants, medical facilities, and industrial facilities that use radioactive materials. These sources can release radiation into the environment, which can have harmful effects on living organisms. Detecting and measuring radiation is essential to ensure the safety of personnel and the public in situations where radiation exposure is a concern.
One of the most significant threats related to radiation is the possibility of a dirty bomb attack. A dirty bomb is a conventional explosive device designed to spread radioactive materials over a wide area, causing damage and harm to the population. The use of a dirty bomb can have severe consequences, including the loss of life, widespread panic, and economic disruption.
Apart from terrorists, there is also the threat of accidents involving nuclear material. Security agencies are increasingly seeking better, smaller, and less expensive detection devices to detect and prevent this type of terrorist attack.
Radiation is an important part of CBRN (Chemical, Biological, Radiological, Nuclear) detection and response. Radiological threats, such as radioactive materials, can be extremely hazardous to human health and the environment. Detection of radiation can help identify the presence of radioactive materials and provide early warning of potential radiological hazards.
For in-depth understanding of CBRN technology and applications please visit: CBRN Counterterrorism: Strategies for Prevention, Detection, and Response
In recent years, governments and private organizations around the world have invested heavily in the development and deployment of radiation detection technologies to mitigate the threat of dirty bomb attacks. Advanced sensors, portable radiation detectors, and other technologies are being deployed in high-risk areas to detect and monitor any potential threat. These technologies have also been integrated into transportation systems, border checkpoints, and other critical infrastructure to ensure the safety of the public and prevent the spread of radioactive materials.
In recent years, there have been significant advancements in radiation detection technology, and these technologies have played a vital role in improving our understanding of radiation and its effects. In this article, we will discuss the latest advancements in radiation detection technology for defence, aerospace, and industrial applications.
Introduction to Radiation
When radioactive elements decay, they produce energetic emissions (alpha particles, beta particles, or gamma rays) that can cause chemical changes in tissues. Gamma and X-rays can travel long distances in air and can pass through the body exposing internal organs; it is also a concern if gamma emitting material is ingested or inhaled.
Beta radiation can travel a few yards in the air and in sufficient quantities might cause skin damage; beta-emitting material is an internal hazard if ingested or inhaled. Alpha radiation travels only an inch or two in the air and cannot even penetrate skin; alpha-emitting material is a hazard if it is ingested or inhaled.
Alpha Particles are the cores (nucleus) of helium atoms. Even though they are easily stopped, they can damage the atoms of whatever they strike. Beta Particles – Beta particles are electrons flying along without the rest of the atom. It takes a little more to stop a beta particle, but thin metal – even tinfoil will stop most of them. Gamma Radiation – Gamma rays are made of the same particles as non-ionizing radiation, but at much, much higher energies. Gamma Rays come from the decay of radioactive elements here on Earth. Gamma Rays are very hard to stop, and a Gamma source even quite distant from the body can be very dangerous.
The average person in the United States receives a “background” dose of about one-third of a rem* per year— about 80% from natural sources including earth materials and cosmic radiation, and the remaining 20% from man-made radiation sources, such as medical x-rays. * A rem is a measure of radiation dose, based on the amount of energy absorbed in a mass of tissue. Dose can also be measured in Sieverts (1 Sievert=100 rem).
Radiation Detectors
Radiation detectors are instruments used to detect and measure the presence of radiation in the environment. There are various types of radiation detectors available, including ionization chambers, Geiger counters, scintillation detectors, solid-state detectors, and neutron detectors.
A variety of detectors can be used in radiation monitoring systems, but the most common types fall into one of two basic designations: crystalline-based materials and gas-filled chambers. Both configurations are based on the movement of free electrons moving through a medium and the accumulation and control of ions through electrical methods. It is important to note, however, that while some of the same detection principles apply to neutron radiation, the detection and measuring of neutron generally requires specialized equipment and a different set of analysis factors.
The available radiation detecting technologies is of three type
- Semiconductor detectors, eg. Si, Ge, GaAs, CdTe;
- Gaseous detectors, eg. propotional counters, Gas Electron Multiplier (GEM) detectors;
- Scintillators, e.g. metamaterials (SMM).
As the requirements for greater accuracy, efficiency, or sensitivity increases, so does the complexity of the detector and its operation. Reliable quality assurance (optical and electrical) prior to installation is essential to guarantee reliable performance of
detectors, interconnections and electronics.
Some of the types of commonly used detectors are:
Geiger counter
The most common detector is the Geiger-Mueller counter, commonly called the Geiger counter. It uses a gas-filled tube with a central wire at high voltage to collect the ionization produced by incident radiation. It can detect alpha, beta, and gamma radiation although it cannot distinguish between them. Because of this and other limitations, it is best used for demonstrations or for radiation environments where only a rough estimate of the amount of radioactivity is needed.
Scintillation detectors
Scintillators are usually solids (although liquids or gases can be used) that give off light when radiation interacts with them. The light is converted to electrical pulses that are processed by electronics and computers. Examples are sodium iodide (NaI) and bismuth germanate (BGO). These materials are used for radiation monitoring, in research, and in medical imaging equipment.
Si photodiodes have no internal gain and often rely on low noise properties of externally connected amplifiers for better S/N. These lightweight and compact photodetectors are suitable for compact scintillation-based radiation detectors without an identification function. Photomultiplier tubes (PMT) can vary in size ranging from 8 mm to more than 100 mm in diameter. Their high internal gain of up to 10⁶ and extremely low dark count make them the best detectors for all types and sizes of scintillation-based radiation detection systems.
An MPPC consists of multiple avalanche photodiode pixels operating in Geiger mode. These lightweight and compact photodetectors have high internal gain of up to 10⁶, making them the best alternative for your scintillation-based radiation detection system.
Solid state X-ray and gamma-ray detectors
Silicon and germanium detectors, cooled to temperatures slightly above that of liquid nitrogen (77 K), are used for precise measurements of X-ray and gamma-ray energies and intensities. Silicon detectors are good for X-rays up to about 20 keV in energy.
Germanium detectors can be used to measure energy over the range of >10 keV to a few MeV. Such detectors have applications in environmental radiation and trace element measurements. Germanium gamma ray detectors play the central role in nuclear high-spin physics, where gamma rays are used to measure the rotation of nuclei. Large gamma-ray detection systems, such as Gammasphere and Eurogam are made of these detectors.
Neutron detectors
Neutrons are much harder to detect because they are not charged. They are detected by nuclear interactions that produce secondary charged particles. For example, boron trifluoride (BF3) counters make use of the 10B(n,a)7Li reaction to detect neutrons.
Often one uses a moderator, such as paraffin, to slow the neutrons and thus increase the detection efficiency. These detectors are used to monitor the neutron fluxes in the vicinity of a reactor or accelerator. Liquid scintillators can measure both neutrons and gamma rays. By carefully measuring the shape of the electronic signal, scientists can and distinguish between these two types of particles.
Advancements in Radiation Detectors
The development of advanced radiation detection technology has been critical in mitigating the threat of dirty bomb attacks. Radiation detectors are used to monitor high-risk areas for any signs of radioactive material, allowing security personnel to detect and respond to any potential threat quickly. The latest advancements in radiation detection technology have made these detectors even more effective, with the ability to detect and analyze a broad range of radioactive materials.
Graphene-based radiation detectors: Researchers have developed a new type of radiation detector that uses graphene as its sensing material. The graphene-based detector can detect gamma rays with high precision and sensitivity, making it a promising tool for detecting radioactive materials in the environment.
Another recent advancement in radiation detection technology is the use of artificial intelligence (AI) to analyze radiation data. AI algorithms can analyze large amounts of radiation data in real-time, providing operators with accurate and timely information about radiation levels and sources. This technology is particularly useful in nuclear power plants, where radiation levels need to be monitored constantly, and any anomalies need to be detected and addressed immediately.
In addition, there have been advancements in portable radiation detection technology. Portable radiation detectors allow personnel to detect and measure radiation levels in remote or inaccessible areas. These devices are small, lightweight, and easy to use, making them ideal for emergency response teams, first responders, and military personnel.
Other advancements in radiation detection technology include the development of wearable dosimeters, which can measure radiation exposure levels in real-time, and the use of drones to map and detect radiation sources in hard-to-reach areas.
New Semiconductor material based Neutron Detector Can Fit In Your Pocket
Researchers at Northwestern University and Argonne National Laboratory have developed a highly efficient and stable semiconductor-based neutron detector that can fit in your pocket. The detector can absorb neutrons and generate electrical signals that can be easily measured, introducing a new third class of neutron detectors.
Most neutron detectors currently in use are either scintillators or use helium gas, which are very large in size. When heavy elements, such as uranium and plutonium, decay, their atoms eject neutrons from their nuclei. Most neutron detectors are so-called scintillators that work by sensing ejected neutrons and then emitting light to alert the user.
The new semiconductor material lithium-indium-phosphorous-selenium, enriched with the lithium-6 isotope, is layered in structure and can detect thermal neutrons within nanoseconds while discriminating between other types of nuclear signals, preventing false alarms. The semiconductor-based detector is also highly efficient and stable. The detector has significant applications in national security, radiation safety, astronomy, plasma physics, materials science, and crystallography.
US Navy develops new radiation detector without relying on scarce Helium-3
The US Navy has been assigned a new patent for a radiation detection technology that uses a new type of gas counter to detect thermal neutron radiation without relying on scarce Helium-3 gas.
The only source of Helium-3 is decayed Tritium from a nuclear reactor, and only one reactor in the U.S. is producing it. Each year, thousands of liters of Helium-3 gas is made available for government research, national security activities, and medical diagnostic procedures. But demand as high as 70,000 liters per year can outpace government supply, due to a substantial increase in the use of neutron detectors for homeland and national security applications, according to the Department of Energy.
The technology was invented by scientists at the Naval Research Laboratory and the DOE’s Los Alamos National Laboratory. The gas counter uses dense Xenon gas, which is added to rectangular gas tubes, to improve the detector efficiency and reduce the consumption of Helium-3 by four-fold, achieving an estimated cost saving of $20,000 to $30,000 per detector. This innovation is crucial, as the current demand for Helium-3 outpaces the government’s supply due to the increasing use of neutron detectors for national security and homeland security applications.
Gallium-Nitride Transistors
NASA teams are investigating the use of gallium nitride (GaN) in space exploration as it has less electrical resistance, can handle 10 times the electrical current of silicon, is resistant to radiation and can detect energetic particles. However, GaN transistors have not yet been used in space instruments due to the lack of established standards characterizing their performance when exposed to extreme radiation in space.
Neutrons can be generated by energetic events in the Sun as well as cosmic ray interactions with Earth’s upper atmosphere. The neutrons generated by cosmic rays in the atmosphere can add to Earth’s radiation belt—a swatch of radiation surrounding Earth that among other things can interfere with onboard satellite electronics—when they decay. Researchers have discovered GaN can form the basis of a highly sensitive neutron detector. “The gallium-nitride crystal could be game-changing for us,” de Nolfo said.
To address this, NASA, Los Alamos National Laboratory, a parts manufacturer, and the NASA Electronic Parts and Packaging are working to establish criteria for GaN devices. The researchers are also exploring the use of GaN crystals for highly sensitive neutron detectors that do not require moving parts and would use little power.
Ceramic insulator in Mobile phone could reveal your radiation exposure after a nuclear disaster
A ceramic insulator commonly found in mobile phones and fitness trackers can reveal past nuclear radiation exposure when heated to high temperatures, according to a 2019 study. The method could allow experts to determine someone’s radiation dose in a matter of hours, which could help with emergency medical treatment after a nuclear disaster. When the ceramic insulator is exposed to nuclear radiation, the radiation rearranges the distribution of electrons in defects in the ceramic’s crystalline structure, and the wavelengths of light that make up that luminescence can reveal the material’s electron distribution when heated. The machine used to measure the ceramic’s luminescent glow costs about $150,000, so people in areas affected by nuclear disasters would have to send their personal electronics to specialized facilities for testing.
Radiation detection technology has been employed in many incidents
Radiation detection technology has played a crucial role in several past incidents, highlighting the importance of these technologies in mitigating radiation threats. In 2011, following the Fukushima nuclear disaster, radiation detectors were used to monitor radiation levels in the surrounding areas and ensure the safety of personnel and the public. The use of portable radiation detectors allowed emergency response teams to assess the situation quickly and take appropriate measures to minimize radiation exposure.
Similarly, in 1986, following the Chernobyl nuclear disaster, radiation detection technology played a critical role in monitoring radiation levels and identifying contaminated areas. Radiation detectors were used to detect and measure the levels of radiation in the surrounding areas, enabling emergency response teams to take appropriate measures to protect the public and minimize radiation exposure.
In the industrial sector, radiation detection technology has been instrumental in ensuring the safety of workers who handle radioactive materials. In 2005, a radiography device containing high levels of radioactive material was lost in Texas, prompting an emergency response. Radiation detectors were used to locate the device and ensure the safety of the public and emergency response personnel.
In conclusion, past incidents and case studies highlight the importance of radiation detection technology in mitigating radiation threats. These technologies have played a crucial role in ensuring the safety of personnel and the public in situations where radiation exposure is a concern. The use of portable radiation detectors and advanced sensors has enabled emergency response teams and other personnel to detect and measure radiation levels quickly and accurately, enabling appropriate measures to be taken to minimize radiation exposure. The latest advancements in radiation detection technology have made these technologies even more effective and reliable, ensuring that we can continue to protect human health and the environment from the harmful effects of radiation.
Defense Aerospace and Industrial Applications
Defence and aerospace applications require highly advanced and sensitive radiation detectors. The new radiation detecting technologies developed for these industries are highly specialized and can detect and measure even the smallest amounts of radiation. These technologies include neutron detectors, which can detect and measure neutron radiation, a highly penetrating form of radiation that can pass through thick materials. Additionally, there are X-ray detectors that can detect X-rays emitted by radioactive materials, and gamma ray detectors that can detect gamma rays, another highly penetrating form of radiation.
The industrial sector also benefits from radiation detection technology, as it is essential to monitor radiation levels in facilities that use radioactive materials. One recent advancement in radiation detection technology for industrial applications is the Multi-Sensor Radiation Detector (MSRD) developed by the Naval Sea Systems Command (NAVSEA) in collaboration with the Naval Nuclear Laboratory and the Department of Energy. The MSRD combines three different radiation detection technologies, including a solid-state detector, a gas proportional detector, and a neutron detector, to detect and locate radiation sources quickly and accurately. The MSRD is also equipped with GPS technology to track and map radiation sources in real-time, making it a valuable tool for radiological response in shipyards and other industries.
In addition, there have been advancements in portable radiation detection technology. Portable radiation detectors allow personnel to detect and measure radiation levels in remote or inaccessible areas. These devices are small, lightweight, and easy to use, making them ideal for emergency response teams, first responders, and military personnel.
One of thrust areas of DARPA is to counter CBRNE threats by developing and testing networked, mobile and cost-effective nuclear- and radiological-weapons detectors that can easily be deployed to provide real-time surveillance over city-scale areas. DARPA under their SIGMA program had designed a pocket-sized radiation detector to help foil terrorists attempting to detonate concealed dirty bombs or full-blown nuclear weapons in or around U.S. cities and crucial government and industrial infrastructure. Direct measurement of gamma and neutron emission remains one of the few definitive to detect and identify special nuclear materials and radiological sources, DARPA officials say.
Conclusion
Overall, the threat of a dirty bomb attack remains a significant concern, and radiation detection technology continues to play a crucial role in mitigating this threat.
The importance of radiation detection for mitigating radiation threats cannot be overstated. Radiation exposure can have severe consequences for human health, including radiation sickness, cancer, and death. Therefore, detecting and measuring radiation levels is essential for ensuring the safety of personnel and the public in situations where radiation exposure is a concern.
Radiation detection technology allows us to identify and locate radiation sources quickly and accurately, enabling emergency responders and other personnel to take appropriate measures to mitigate radiation exposure. Without these technologies, it would be challenging to respond to radiation incidents effectively, and the consequences could be catastrophic.
The use of advanced sensors and detectors has made it possible to detect and respond quickly to any potential threat, ensuring the safety of the public and preventing widespread panic and economic disruption. As technology continues to advance, we can expect to see even more effective and reliable radiation detection technologies deployed in high-risk areas around the world.
Thus, radiation detection technology is a crucial component of radiation safety and plays a critical role in protecting human health and the environment from the harmful effects of radiation.
