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Borehole radar (BHR) is one of the most important types of ground-penetrating radar and has very strict requirements for antenna. Considering the detection resolution and the limited borehole size, the BHR antenna should be both wideband and compact. In this article, a compact nonsymmetric wideband dipole (NSWD) antenna is proposed. One arm of the NSWD antenna consists of several patches with different lengths, and the other one is a hollow metal tube. The combination of patches which are resistively loaded at the ends is used for increasing antenna bandwidth and frequency reconstruction. In addition, a three-section binomial matching transformer is designed for impedances match between antenna ( $120~\Omega$ ) and coaxial cable ( $50~\Omega$ ). Matching transformer and other radar system devices are housed in the hollow metal tube, which makes the BHR system much compact. The central frequency of the antenna is set to 86 MHz for long-range detection. The proposed antenna is fabricated and measured. The measurement results show that the proposed antenna has the advantages of wide bandwidth (~41.8% from 68 to 104 MHz) and high radiation efficiency (~65%). Finally, the antenna (including electronics) is assembled into a polyvinyl chloride pipe to form a BHR prototype, and we used it to conduct a field test in a water-filled borehole. The experimental results show that the NSWD antenna can work well with the BHR system inside borehole.

An ultrawide band (UWB) antipodal Vivaldi antenna is designed for airborne ground penetrating radar (GPR) system. With exponential tapered slots and slot edges, the presented antenna demonstrates a wide operating band from 300 MHz to more than 2 GHz. The fabricated prototype of this antenna with a compact size of 450 mm $\times \,\, 600$ mm $\times \,\, 1.5$ mm has been measured in anechoic chamber. Both simulation and experimental results show that good radiation patterns with gain 4.4–11.5 dBi in the endfire direction could be achieved in the whole working band, which indicates that the proposed antenna is suitable for airborne GPR application.

In this study, a ground-based radar system with two multiple input multiple output (MIMO) arrays is developed for 2D displacement estimation applications. To reduce the influences of antenna position error, channel delay, and phase/gain difference on the imaging quality, calibration methods and phase coherence factor (PCF) based filtering methods are applied. For each MIMO array, target displacement can be measured along its line of sight direction. Co-registration is conducted to help to derive the 2D displacement vector estimations of the targets.

An Ultrawideband Antipodal Vivaldi Antenna with compact structure for borehole radar application is reported in this paper. The antenna is embedded in a cylindrical fiber-reinforced plastic (FRP) structure, operating in the frequency range from 600 MHz to more than 4 GHz. A metal reflector is attached to the cylindrical FRP to improve the direction of the antenna especially in low frequency. The simulation results show that good radiation patterns with direction of 4.6–8.7 dBi in end-fire direction is achieved in the whole working band, which indicates that the proposed antenna is suitable for directional borehole radar system.

The HI-13 tandem accelerator in the China Institute of Atomic Energy (CIAE) is a multi-user facility. Only a small part of the beam time can be used for AMS. So, it is impossible to measure very many samples and to carry out wider applications by using the HI-13 tandem AMS system. Therefore, we focus our studies on the development of measurement and detection methods and several interesting applications utilizing the long-lived radionuclides 26Al, 41Ca, 36Cl and 79Se.

Angular distributions of elastic and inelastic scattering have been measured for152Sm+12C at 63.2 MeV and148Nd+16O at 90.9 MeV. An evident interference pattern in the inelastic scattering has been observed for the first time in a strong Coulomb coupling system.

Elastic recoil detection analysis technique with ?E - E particle identification and Q3D momentum analysis has been developed to determine high resolution depth profiles in thin foils and multilayer systems. A depth resolution of 1.2nm was achieved at the surface of the samples using a high quality 100MeV 127I beam. The method was applied to depth profile analysis of C/LiF multilayers, superconductor and GaN foil samples.

The mass of 168Dy has been measured for the first time using the two-proton pick-up reaction 170Er(18O,20Ne) at an 18O energy of 104 MeV. The products of the reaction were detected at the focal plane of the Q3D spectrometer. The Q value of the 170Er(18O,20Ne) 168Dy reaction was found to be 4.71 ± 0.14 MeV . The mass excess of 168Dy was deduced to be −58.57 ± 0.14 MeV.

A Q- value of 4.046 ±0.102 MeV has been determined for the two protons transfer reaction 160Gd(18O, 20Ne) 158Sm at 98.95 MeV. This result yields a first experimental measured value of − 65.738 ± 0.102 MeV for the mass excess of 158Sm, the nucleus far from stability. The result is compared with current theoretical predictions.