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We characterize a single titanium (Ti) transition edge sensor (TES) designed for in situ detection of individual \He2^{\ast} excimers. We find a critical temperature of 420 mK, an electrothermal time constant of \sim\!\! 3\ \mu\s, and a total energy resolution of 1.5 eV. We observe the detector response to short laser pulses and present a successful analysis strategy for extracting direct-TES-hit pulses from a much larger background (due to substrate hits). We also present the response of a similar Ti TES with a built-in aperture designed to eliminate substrate background; this device has an energy resolution of better than 1.5 eV and a much reduced substrate signal. We discuss near-term plans for coupling multiple such TESs together with a shared aluminum (Al) absorber, increasing the \He2^{\ast} collection area to millimeter scales. [ABSTRACT FROM PUBLISHER]

Abstract: Ti 15V–3Cr–3Sn–3Al, sometimes referred to as Ti 15-3-3-3 or “Magic Titanium”, is a candidate material for components requiring high mechanical strength and low thermal conductivity at cryogenic temperatures. The electrical resistance of Ti 15-3-3-3 was measured between 230mK and room temperature, and the thermal conductivity between 230mK and 7.7K. A superconducting transition was observed at T C =3.89±0.01K. Below the superconducting transition temperature, the thermal conductivity was fitted to a function of the form , where α =0.043±0.002W/(mK2) and β =0.27±0.01. Above T C , the thermal conductivity of Ti 15-3-3-3 was fitted to a function of the form λ(T > T C )= γ · T δ , where and δ =0.4±0.05. The thermal conductivity of Ti 15-3-3-3 is compared with other materials commonly used for the construction of thermally isolating support structures. Ti 15-3-3-3 is shown to exhibit one of the lowest ratios of thermal conductivity to mechanical strength and is thus particularly well suited for such applications. [ABSTRACT FROM AUTHOR]

Correction [ABSTRACT FROM AUTHOR]

Abstract: Eccosorb CR-124 is a castable iron-loaded epoxy resin with excellent absorption properties for electromagnetic waves in the GHz range. It is commonly used in low temperature instruments to absorb thermal radiation. The specific heat of Eccosorb CR-124 was measured between 800mK and 6K with the heat pulse method. The results were fitted to the function , with T being the temperature in Kelvin. In addition, the thermal diffusivity of Eccosorb CR-124 was determined. At a temperature of 2.3K, a peak is observed in . Consequently, the thermal conductivity of Eccosorb CR-124 features two distinct regimes. Below 2.3K, it fits the function . Above 2.3K, it fits the function . [Copyright &y& Elsevier]

Abstract: Tests and quality controls of new Gas Electron Multipliers (GEMs) are described. Following the Design of Sauli, GEMs have been manufactured by Tech-Etch, a private company located in Plymouth, Massachusetts. A major improvement in efficient quality control has been achieved through the use of a specifically developed automatic scanning device. [Copyright &y& Elsevier]

Abstract: Zylon is a synthetic polyurethane polymer fiber featuring very high mechanical strength. Measurements of the thermal conductivity of high modulus Zylon fibers at temperatures between 400mK and 4K were performed to assess if they can be successfully employed in the design of high performance suspension systems for cold stages of adiabatic demagnetization refrigerators. The linear mass density of the yarn used in these measurements amounts to 3270 dtex, which is also a measure for the yarn’s cross section. [1] A linear mass density of 1 tex is equivalent to a yarn mass of 1g/km. High modulus Zylon has a density of 1.56g/cm3. 1 The experimental data for the thermal conductivity was fitted to a function of the form . This result was normalized to the breaking strength of the fibers and compared with Kevlar. It shows that Kevlar outperforms Zylon in the investigated temperature range. At 1.5K, the thermal conductivity integral of Zylon yarn is twice as high as the thermal conductivity integral of Kevlar yarn with the same breaking strength. [Copyright &y& Elsevier]