Recently new scintillators such as GSO, YAP(Ce), YAG:Ce etc. are developed. Also new applications with scintillators are researching in physics, nuclear, industry and astronomy. Devices such as multi-anode PMT, Photodiode, CCD are developing to use these new scintillators and applications.

  Recent application of alkali-halide scintillators to various fields has been reviewed. Scintillation mechanism for pure CsI studied by Nishimura group is introduced. Scintillation characteristics on light output and decay curves from CsI(Tl) and NaI(Tl) under various charged particle excitation are reviewed. Further subjects on alkali-halide scintillators have been presented. The relation between Auger-free core luminescence and Auger-electron emission is briefly described.

  Recent development in γ ray detectors using new oxide crystal scintillators for PET (positron emission tomography) and SPECT (single photon emission computed tomography) is reviewed. Characteristics of the new scintillators and three types of typical detectors which are (a) 2 dimensional scintillator array + 4 PMTs, (b) 2 dimensional scintillator array + PS-PMT and (c) single plate scintillator + PS-PMT are pointed out. Some results on the research for each type of detectors are also described.

  As a new method of radiation measurements, several optical methods usisng optical fiber sensors have been developed. One is the application of "radio-luminescence" from the optical fiber itself such as plastic scintillating fibers. Another researches are made to develop the "combined-sensors" by combination of optical fibers and scintillating materials. Using the time domain method of optical fiber sensors, the profile of radiation distribution along the optical fiber can be easily determined. A multi-parameter sensing system for measurement of radiation, temperature, stress, etc, are also expected using these optical fiber sensors.

  A new type beta-ray detector for surface contamination monitoring is described in this paper. It consits of a thin plastic scintillator and some wavelength shifting fibers. The light collection using wavelength shifter at the edge of the thin scintillator improves the sensitivity uniformity and minimizes the total thickness of the detector.

  With the aim of simultaneous counting of various radiations emitted from actinides, phoswich detectors have been developed by combining multiple scintillators, viz., ZnS(Ag) for α counting plus other scintillator(s), such as anthracene for β and fast-neutron counting, NaI(Tl) for γ counting and/or ⁶Li glass for thermal-neutron counting. The simultaneous counting was achieved by using a pulse-shape discrimination technique. In addition, optical filters, such as ND, sharpcut and bandpass filters, were found to be effective for pulse-height and pulse-shape control of output signals from the ZnS(Ag), which would have multiple emission components with different decay times. The filters were then used, if necessary, to improve the discrimination properties of the phoswiches. The application of a phoswich detector to two different types of concentration monitor for actinide solution was also tried. The phoswich detector system will hopefully offer bright prospects for advanced actinide monitoring by applying appropriate optical technologies, such as light transmission through optical fiber.

  A neutron detector based on scintillation fibers with directionality has been developed for the measurement of 14 MeV neutrons from secondary DT reactions in the Deuterium plasma on the JT-60U tokamak. This detector uses a fiber-matrix geometry, a magnetic field- insensitive photomultiplier tube with an active high voltage base and 300 MHz discriminator to reject low-level pulses from 2.5 MeV neutrons and gamma rays. The pulse height distribution and the directionality for 14 MeV neutrons have been measured using the Ion Beam Facility of the Los Alamos National Laboratory and the FNS DT neutron generator of JAERI. The detecors have been installed on the JT-60U tokamak with compact collimators. The measurements of the 14 MeV neutron time evolution have been performed on the neutral beam heated plasmas.

  Recent application of organic liquid scintillator is reviewed. According to progress of Monte Carlo simulation code of response function, an application of in-situ neutron spectrometry is extended to 14MeV neutrons related to fusion reactor development and to intermediate energy neutrons for high energy accelerator application. Also a gamma-ray spectrometry is being carried out inside a bulk material. These recent studies are performed by needs in a variety of experiments.

  X-ray detectors using avalanche photodiodes (APDs) have been developed for fast counting measurements. One of the APD detectors has a stack of four silicon APDs. The stack of APDs improves intrinsic efficiency for X-rays, such as 55% at 16.53 keV. The output rates reaches 4.6×10⁸ counts/s at 16.53 keV. The dynamic range of more than 10¹⁰ is useful for synchrotron X-ray diffraction experiments.

  This survey of photostimulated luminescence (PSL) has three main thrusts: basic mechanism of PSL phenomenon, photostimulable phosphors as materials for imaging plate (IP) and its application to advanced radiation detection. In the right of the survey, it can be said that the IP utilizing the PSL in alkali halides and II-VI compound phosphors is one of the most attractive candidates for an advanced two-dimensional imaging sensor and a novel dosemeter for ionizing radiation.

  Recent advanced electron linear accelerators can produce a subpicosecond relativistic electron pulse, which are going to be applied to pulseradiolysis analysis for radiation chemistry and physics and free electron laser etc. There are two major methodologies to evaluate the subpicosecond electron pulse, which are the femtosecond streak camera measurement via Cherenkov radiation and coherent far-infrared transition radiation interferometry. Both measurements have been carried out and comparied with each other at the S-band twin linear accelerators of Nuclear Engineering Research Laboratory, University of Tokyo. The theory, results, precision and problems are reviewed here..

  Fast neutron measurements using a three-dimensional tracking detector consisting of scintillating fibers have been performed. The detector is composed of 100 layers of 100 0.5mm square fibers each bundled together by 0.5mm thick flat belts. The fibers in consecutive layers are arranged perpendicular to each other. The part where the fibers cross is the detection volume of 5×5×5 cm³. The stack of 100×100 fibers is coupled to an image intensifier. In this study, the detector has been tested with a 650MeV/n ⁴⁰Ar beam. Although energetic ions and fast neutrons enter the detector simultaneously, the particles can be identified by observing the intensity per unit length of the track. The detector is expected to be used as a space dosimeter for fast neutrons.