Chun-Yen Chen

A feasibility study of boron-loaded liquid scintillator for the detection of electron anti-neutrinos

Abstract Boron-loaded liquid scintillator offers some potential advantages as a detector for electron anti-neutrinos. A research program was carried out with the objective of developing such scintillators. The crucial feature is the pulse shape discrimination properties following the neutron capture by 10 B. Results of the R&D efforts are presented. The feasibility and the technical difficulties of carrying out a full-scale neutrino experiment based on this approach are discussed.

Prospects of scintillating crystal detector in low-energy low-background experiments

A scintillating crystal detector offers potential advantages in low-energy (keV-MeV range) low-background experiments for particle physics and astrophysics. The merits are discussed using CsI(T1) crystal as illustrations. The various physics topics, which can be pursued with this detector technology, are summarized. A conceptual design for a generic detector is presented

An automatic construction of a person's face model from the person's two orthogonal views

A new approach to the construction of a persons three-dimensional face model from the persons two orthogonal views is presented. This approach is a no hair-style interference method, which constructs the persons face model and hair model independently. The persons fine facial structures, i.e., eyes, nose, and lips, as well as the persons outline in two orthogonal views are obtained. A feature-based generic three-dimensional bald head model is then used to adjust its predefined features to fit the persons fine structures and outline morphologically in two respective views. The independently obtained three-dimensional hair model is put on the morphed bald head model to be the persons three-dimensional geometrical face model. The persons realistic face model is finally obtained by using the texture mapping of the persons image in two orthogonal views onto the persons three-dimensional face model. This paper shows the detail process of the construction of a persons face model from the persons two orthogonal views.

A novel transition radiation detector utilizing superconducting microspheres for measuring the energy of relativistic high-energy charged particles

Abstract A novel transition radiation detector (TRD) utilizing superheated superconducting microspheres of tin of 22–26, 27–32 and 32–38xa0μm in diameter, respectively, has been constructed which is capable of measuring accurately the energy of relativistic high-energy charged particles. The test has been conducted in a high-energy electron beam facility at the CERN PS in the energy range of 1–10xa0GeV showing an energy dependence of the TR X-ray photon produced and hence the value γ = E / mc 2 of the charged particle.

Dating thin zircon rims by NanoSIMS: the Fengtien nephrite (Taiwan) is the youngest jade on Earth

Nephrite in the Fengtien area of the eastern part of the Central Mountain Range, Taiwan, is associated with antigorite-serpentinite within the Yuli belt, a late Cenozoic subduction–accretionary complex related to the eastward subduction of the South China Sea plate forming the Luzon arc. Diopsidite and clinozoisite rock are two other metasomatic components accompanying nephrite between serpentinites and the greenschist-facies country rock (carbonaceous material-)quartz-mica schist. Detrital zircons were separated from one clinozoisite rock sample, formed through metasomatic replacement after mica-quartz schist at temperatures of 320–420°C or slightly lower, which is lower than the metamorphic temperature conditions of the Yuli belt. Most of the detrital zircons have thin zircon rims less than 15–20 μm wide. These zircon rims, considered as newly formed during metasomatism leading to nephrite/diopsidite/clinozoisite rock formation, were dated by a high lateral resolution secondary ion mass spectrometer (CAMECA NanoSIMS NS50). The resulting 238U/206Pb-204Pb/206Pb inverse isochron gave an age of 3.3 ± 1.7 Ma. The collision of the Eurasian continental margin with the Luzon arc has been suggested to have begun at ca. 6.5 Ma in the Taiwan area. The nephrite formation processes therefore clearly post-dated South China Sea plate subduction. The present date, substantiated by the metamorphic and metasomatic temperature information, demonstrates that the fluid–rock interaction forming Fengtien nephrite would have taken place during a Barrovian-type metamorphic overprint resulting from arc-continent collision, leading to the exhumation of the Yuli belt. This conclusion on nephrite formation with regard to regional tectonics can serve as a working model for future studies on other nephrite deposits with similar occurrences, mostly embedded within Mesozoic or older subduction-accretionary complexes. The Fengtien nephrite deposit is therefore the youngest one of its kind exposed on Earth’s surface.