Scintillator-based High Sampling Frequency Fiber Optic UV Radiation Sensor

Ultraviolet(UV)light is a general term for radiation with a wavelength range of 10-400 nm in the electromagnetic spectrum.It is widely used in the fields of sterilization,high-voltage equipment leakage detection,military UV communication,missile warning,etc.At present,UV detection technology has become another dual-use optoelectronic technology developed after infrared and laser technology.However,the UV intensity measuring devices currently on the market have low sampling frequency,leading to a poor measurement accuracy,and cannot be used in complex environments such as underwater or strong electromagnetic fields.Therefore,it is necessary to design a fiber-optic UV sensor used for high-frequency real-time detection in complex environments.A high sampling frequency fiber UV sensor based on scintillator has been designed in the article.The sensor based on scintillator material and plastic optical fiber not only overcomes the problems,that traditional UV sensors have not a capable to be used in complex environments such as underwater,strong electromagnetic field,but also has features of good linear response,high sampling frequency,small temperature coefficient,simple structure,small volume and flexibility.The article first set up a test system to test the performance of the sensor,which expound theories and implementations of linear response,repeatability,temperature response,sample frequency and signal acquisition.And the test system also explained the transforming relationship between the fluorescence yield from the sensor and UV power density.In this system,the response of five common high-energy ray-converting scintillator materials under 308 nm UV excitation was investigated,and the best response linearity and highest response intensity scintillator materials was selected as the sensitive material in the sensor.A side window probe was designed whereby the material,and its repeatability,temperature characteristic and sampling frequency were tested.The sensor was compared with a commercial UV irradiation meter in linearity.The test results show that the side window fiber probe has the characteristics of good repeatability,small temperature coefficient and high sampling frequency,and the linear response is slightly better than that of commercial sensors.After that,the comparative analysis of the signal processing methods at the distal sensor testified the feasibility of using the narrow-band spectral integration method,and illustrates the possibility of using the photomultiplier tube as the acquisition device.In order to facilitate the array UV detection system,a kind of end window probe was proposed above the basics of side window probe,and we built a detection system for the sensor.End window probes inherit the advantages of side window probes and will be easier to assemble into array detectors.The measuring system composed of the collecting device built by the photomultiplier tube also has the advantages of good response linearity and high sampling frequency.The high sampling frequency can monitor the change of the UV intensity in real time,and the effect is better than the similar measuring equipment in the market.Therefore,the work done in this paper provides a method for measuring real-time UV radiation.