China 
Africa 
Explore chapters and articles related to this topic
Indoor Air Quality and Ventilation Measurement
Published in Dejan Mumovic, Mat Santamouris, A Handbook of Sustainable Building Design and Engineering, 2018
Lia Chatzidiakou, Benjamin Jones, Dejan Mumovic
Integrated long-term measurements are often used to assess human exposure and can be performed with a solid-state nuclear track detector (SSNTD). The method offers a cheap and reliable method applicable to large-scale investigations. Alpha particles from radon and its decay products striking the detector cause damage tracks (ISO 11665–4). The detector is a piece of special plastic or film inside a small container (Figure 3.3.3). At the end of the exposure period the container is sealed and returned to a laboratory. The plastic or film detector is treated to enhance the damage tracks (etching). Then the tracks are counted using a microscope or optical reader. The detector then shows the tracks as etching holes or cones, in a quantity proportional to the number of alpha particles that have passed through the detector. Exposure of alpha track detectors is usually 3 to 12 months, but because they are true integrating devices, alpha-track detectors may be exposed for shorter lengths of time when they are measuring higher radon concentrations.
Application of Liquid Membrane Technology at Back End of Nuclear Fuel Cycle—Perspective and Challenges
Published in Anil K. Pabby, S. Ranil Wickramasinghe, Kamalesh K. Sirkar, Ana-Maria Sastre, Hollow Fiber Membrane Contactors, 2020
S. Panja, P. S. Dhami, J. S. Yadav, C. P. Kaushik
Gross α impurity analyses in six different 90Y-acetate batches (each about 140-160 mCi in 4 mL at the time of supply) were assayed after their complete decay using low background ZnS (Ag) scintillator counting system. The results are given in Table 11.4. These results were also validated using the Solid State Nuclear Track Detector (SSNTD) counting system.
Investigation and correlation between surface modifications and field emission properties of laser-induced silicon plasma ion irradiated stainless steel
Published in Radiation Effects and Defects in Solids, 2022
Rizwan Amir, Shazia Bashir, Mahreen Akram, Muhammad Shahid Rafique, Mubashir Javed, Khaliq Mahmood, Wolfgang Husinsky, Shahzeb Ahmad
Nd: YAG (532 nm, 10 ns) laser is used for the production of Silicon plasma ions. Nd: YAG laser after interaction with single crystal Si (100) wafer generates plasma under high vacuum conditions (10−9) torr. The schematic is shown in Figure 1. Si targets were placed on the rotating target holder to rotate them continuously for bringing the fresh surface to each exposure. The target holder was placed in the SS vacuum chamber. By using the turbopump followed by a rotary pump the chamber was evacuated to the base pressure of 10−9 torr. The laser beam with pulsed energy of 190 mJ and irradiance of 15 GW cm−2 after passing through a focusing lens of focal length 50 cm hit the Si target at an angle of 45° with respect to the target surface normal. The high-temperature and high-density Si plasma was generated which is forward peaked. A solid-state nuclear track detector CR-39 was used to detect and identify the laser-generated Si plasma ions. After etching of CR-39 in 6N (NaOH) solution at 70°C for 8 h, the tracks of Si ions were observed by optical microscopy (OLYMPUS STM6). By using the various Nd: YAG pulses ranging from 3000 to 12000, Si targets were exposed.
Bulk etch rates of CR-39 nuclear track detectors over a wide range of etchant (NaOH aqueous solution + ethanol) concentrations: measurements and modeling
Published in Radiation Effects and Defects in Solids, 2020
A latent or ion track is a damage trail at nanometer scale, created by an energetic charged particle, in an insulating solid, commonly known as a solid-state nuclear track detector (SSNTD). Details about the structure of latent tracks can be seen in several recent studies and references therein (1, 2). Latent tracks can be magnified to micrometer scale, using appropriate chemical etching, to make them measurable using optical microscopy. Etched tracks are called nuclear tracks and they are revealed through competition with other etching rate called the detector bulk etch rate. Bulk etch rate is essentially measured in any etching procedures in a simple way. However, it is a complicated process at microscopic scale and needs further investigation.