Surface wave operation mode of the slot antenna microwave plasma source SLAN Polysilicon gate etching in high density plasmas. III. Xray photoelectron spectroscopy investigation of sidewall passivation of silicon trenches using an oxide hard mask Polysilicon gate etching in high density plasmas. II. Xray photoelectron spectroscopy investigation of silicon trenches etched using a chlorinebased chemistry

The axial profile of the axial component of the wave magnetic field B z has been measured for m = 0 helicon waves. A dip in B z is observed at z 25 cm from the antenna, and is explained as a result of the beat between the fundamental and the second-order radial modes of the m = 0 helicon wave. The measured imaginary part of B z , which consists only of the wave field, is compared with that of the calculated wave field using the theory of the uniform plasma case. It is found that 40% of the amplitude arises from the second-order mode and the axial damping length of the fundamental mode 1/k iz 1 70 cm.

For radiological diagnosis and radionuclide therapy, X-ray and gamma-ray imaging technologies are essential. Single-photon emission tomography (SPECT) and positron emission tomography (PET) play essential roles in radiological diagnosis, such as the early detection of tumors. Radionuclide therapy is also rapidly developing with the use of these modalities. Nevertheless, a limited number of radioactive tracers are imaged owing to the limitations of the imaging devices. In a previous study, we developed a hybrid Compton camera that conducts simultaneous Compton and pinhole imaging within a single system. In this study, we developed a system that simultaneously realizes three modalities: Compton, pinhole, and PET imaging in 3D space using multiple hybrid Compton cameras. We achieved the simultaneous imaging of Cs-137 (Compton mode targeting 662 keV), Na-22 (PET mode targeting 511 keV), and Am-241 (pinhole mode targeting 60 keV) within the same field of view. In addition, the imaging of Ga-67 and In-111, which are used in various diagnostic scenarios, was conducted. We also verified that the 3D distribution of the At-211 tracer inside a mouse could be imaged using the pinhole mode.

Strong electric fields inside thunderclouds accelerate electrons up to relativistic energy and cause several types of high-energy atmospheric phenomena. One example is terrestrial gamma-ray flashes (TGFs) coinciding with lightning discharges (

The visualization of drugs is essential for cancer treatment. Although several methods for visualizing drugs have been proposed, a versatile method that can be easily applied to various drugs has not yet been established. Therefore, we propose “activation imaging,” in which a drug is irradiated with thermal neutrons and becomes radioactive, enabling visualization using emitted x rays and/or gamma rays. Activation imaging does not require the conjugation of specific tracers with drugs. Therefore, it can be easily applied to a variety of drugs, drug carriers (e.g., metal nanoparticles), and contrast agents. In this study, neutron activation, gamma-ray spectroscopy, and imaging of drug carriers, anticancer drug, and contrast agents were performed. Gold nanoparticles (AuNPs) and platinum nanoparticles were used as drug carriers, cisplatin was used as an anticancer drug, and gadoteridol and iohexol were used as contrast agents. As a neutron source, the RIKEN accelerator-driven compact neutron source II (RANS-II) was utilized. The imaging was performed using a hybrid Compton camera (HCC). The HCC can visualize x rays and gamma rays ranging from a few keV to nearly 1 MeV, which enables the imaging of various x rays and gamma rays emitted from the activated drugs. As a result, the gamma-ray spectra indicated the generation of radioisotopes through neutron irradiation, and AuNPs and iohexol were visualized.