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Gamma-ray transition edge sensors (TESs) are intensively studied not only to measure isotopic composition of nuclear materials but to monitor transuranic radionuclides inside the human body. We have recently proposed a thick-trilayer membrane as an alternative to silicon-nitride (Si x N y ) single-layer ones. It consists of silicon dioxide (SiO 2 ), Si x N y , and SiO 2 layers. Their total thickness is 6.9 μ m and exhibits almost the same thermal conductance as conventional Si x N y ones with 1- μ m thickness. The thick-trilayer membrane is expected to have better mechanical strength against implementing heavy-bulk absorbers. In this paper, the gamma-ray TES with the thick-trilayer membrane is used to carry out the spectroscopy for the nuclear radiation source. Neptunium-237 and its decay product Protactinium-233 emit 86.5 and 86.6-keV lines, respectively, and they are clearly resolved by four pixels with the full-width-half-maximum (FWHM) resolution of ( 43.7 ± 0.9 ) eV. Furthermore, their intensity ratio agrees with the radioactive equilibrium between the two nuclides. Our experimental results predict that a vast array of pixel formats will reduce the statistical uncertainty in less measuring time. [ABSTRACT FROM AUTHOR]

Background: Helicobacter pylon infection and non-steroidal anti-inflammatory drugs are two major causes of gastric ulceration but interactions between H pylori and these drugs in gastric mucosal injury are unclear. Aims: [...]

A Josephson digital-to-analog (D/A) converter for synthesizing a sinusoidal waveform with metrological accuracy has been developed. The D/A converter is made up of rapid single-flux quantum (RSFQ) logic circuits, a frequency multiplier (FM), a pulse distributor (PD) and voltage multipliers (VM). The VM circuit multiplies the number of RSFQ pulses by a factor of 2 to the nth power. A programmable output voltage is obtained when the input SFQ pulses are gated from the FM to the VMs using PD circuits.

An interface circuit for a Josephson-complementary metal oxide semiconductors (CMOS) hybrid digital system was constructed. The proposed interface circuit consists of a parallel-in-parallel-out circuit and built-in Josephson-MOS amplifiers. It can be used to facilitate broadband data communication between Josephson and CMOS digital systems, amplify small Josephson-output signals and synchronize signals between the two systems.

Thick membranes of the gamma-ray transition-edge sensor (γ -TES) generally exhibit great mechanical strength and can support a bulk metal absorber typical for γ -TES. However, for conventional silicon-nitride (SixNy) membranes, thermal conductance (G) is proportional to the thickness, indicating that thicker membranes provide larger thermal-fluctuation noise in TESs. We propose a thick-trilayer membrane consisting of the silicon oxide (SiO2), SixNy, and SiO2 layers. The SixNy layer accounts for 5.8 μm of the total 6.9 μm, and thus, it is expected to be hard compared with conventional SixNy membranes with a typical thickness below 1 μm. G of the trilayer membrane is characterized as a function of heat-transport distance (L), and the G-L relation follows that of the intermediate model between ballistic and diffusive transports. Resulting G of the thick-trilayer membrane is 1.1–1.7 nW/K, which is not far from the one reported by conventional SixNy membranes. Gamma-ray spectroscopy around 93 keV is carried out based on series biased 5-pixels TES. The best full-width-half-maximum energy resolution among all pixels under characterization is 43.1 ± 1.6 eV for 93-keV, which is close to the median value of a state-of-the-art 236-pixels γ -TES in the literature. The measured low-frequency noise can be represented by theoretical phonon noise and its excess component with the same order as conventional ones. The thick-trilayer membrane is demonstrated to be able to work without any problems in a γ -TES regime. [ABSTRACT FROM AUTHOR]