# State-of-the-Art Mobile Radiation Detection Systems for Different Scenarios
## 4 Mobile Radiation Detection Systems
### Radiation Detection and Gamma Spectrometry
#### 4.2.1 Ground Survey
The use of two detectors also allowed to reduce the survey time (increasing the detection efficiency) and the dose exposure experienced by the operator [66]. Relative to a handheld radiation detection system, [PERSON] et al. [131] used a \(5.08\times 5.08\) cm NaI(Tl) detection system (Figure 7a) with a battery for 7 h autonomy, connected via USB to an advanced processor for scintillators (APS), which in turn was connected via wireless to a smartphone (control and display interface). This detection  
Figure 6: Examples of ground-based mobile detection systems: (**a**) Car-borne survey with two LaBr\({}_{3}\) mounted in the roof. Reproduced, with permission, from Reference [124]; published by Elsevier, 2020, under the terms of the [[https://creativecommons.org/licenses/by/4.0/CC](https://creativecommons.org/licenses/by/4.0/CC)]([https://creativecommons.org/licenses/by/4.0/CC](https://creativecommons.org/licenses/by/4.0/CC)) BY 4.0 license. (**b**) Van with a dose rate counter (top) and a NaI(Tl) spectrometer (bottom). ©2013 IEEE. Reprinted, with permission, from Reference [125]. (**c**) Backpack KURAMA-II for walk surveys using a CsI(Tl) scintillation detector. Reproduced, with permission, from Reference [128]; published by Elsevier, 2018, under the terms of the [[https://creativecommons.org/licenses/by-nc-nd/4.0/CC](https://creativecommons.org/licenses/by-nc-nd/4.0/CC)]([https://creativecommons.org/licenses/by-nc-nd/4.0/CC](https://creativecommons.org/licenses/by-nc-nd/4.0/CC)) BY-NC-ND 4.0 license. system allowed real-time gamma-rays detection, isotope identification, and source localization by using the spin-to-locate (STL) procedure. The STL uses the radiation shielding of the operator's body to estimate the source azimuth. Since this method depends on the attenuation of the gamma-ray flux by the body, its efficiency will depend on the energy of the emitting source. In order to study and ascertain the site for the eventual construction of a nuclear reactor, [PERSON] et al. [38] proposed a set of dose measurements at Kelantan State (Malasya). To accomplish this, a handheld detector (Model 19 microR survey meter, Ludlum) was used composed by a 2.54 cm (diameter) \(\times\)2.54 cm (length) NaI(Tl) crystal, to create a radiation map at a height of 1 m AGL. The higher activity areas were related to the geological soil composition (e.g., granitic origin). [PERSON] et al. [132] developed a personal gamma spectrometer for homeland security and environmental radiation monitoring. The detection system consisted in a \(3\times 3\times 20\) cm\({}^{3}\) Ce-doped Gd-Al-Ga-garnet (Ce:GAGG) crystal coupled to a SiPM (\(3\times 3\) mm\({}^{2}\)) charged by a LiPo battery (3 h autonomy). Since the crystal is coupled to a SiPM, its total weight (battery included) is only 340 g, and it has a low power consumption (2.7 W). This scintillation material featured good technical characteristics: an energy resolution of 5.8% at 662 keV at room temperature, good sensitivity due to its high stopping power (material density of 6.63 g/cm\({}^{3}\)), and a good time response with a decay time of 90 ns shorter than CsI(Tl) and NaI(Tl). [PERSON] et al. [111] developed an alarming PRD to be carried by a FLO. The detection system consisted of a cylindrical 14 mm (diameter) \(\times\) 20 mm (length) CsI(Tl) scintillation sensor optically coupled to a SiPM. This sensor volume was calculated in order to meet ANSI 42.32 sensitivity requirements. In order to obtain the source direction, an array of 2 \(\times\) 2 CsI(Tl) sensors (each sensor with 8 \(\times\) 8 \(\times\) 30 mm\({}^{3}\) crystal coupled to a SiPM) was also considered. The CsI(Tl) crystal was chosen because of its mechanical properties, high density, good light yield and decay time. Its maximum emission wavelength (550 nm) also matches the SiPM quantum efficiency. The detector main features encompass low power consumption, good sensitivity (efficient light collection), low noise, pocket sized, lighter, automatic, robust, clear, and simple indication of radiation field presence and intensity.