Three-element trap filter radiometer based on large active area silicon photodiodes.

This paper shows the opto-mechanical design of a new filter radiometer built at the Physikalisch-Technische Bundesanstalt, Germany, for the accurate determination of the thermodynamic temperature of high-temperature blackbodies. The filter radiometer is based on a three-element reflection-type trap detector that uses three large active area silicon photodiodes. Its spectral coverage and field of view are defined by a detachable narrow-band filter and a diamond-turned precision aperture, respectively.

Thermodynamic temperature assignment to the point of inflection of the melting curve of high-temperature fixed points.

The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.

Performance assessment of time-domain optical brain imagers, part 1: basic instrumental performance protocol.

Performance assessment of instruments devised for clinical applications is of key importance for validation and quality assurance. Two new protocols were developed and applied to facilitate the design and optimization of instruments for time-domain optical brain imaging within the European project nEUROPt. Here, we present the "Basic Instrumental Performance" protocol for direct measurement of relevant characteristics.

Microscopic origin of the '0.7-anomaly' in quantum point contacts.

Quantum point contacts are narrow, one-dimensional constrictions usually patterned in a two-dimensional electron system, for example by applying voltages to local gates. The linear conductance of a point contact, when measured as function of its channel width, is quantized in units of GQ = 2e(2)/h, where e is the electron charge and h is Planck's constant. However, the conductance also has an unexpected shoulder at ∼0.

Method for the calibration of the spectral irradiance of tungsten filament transfer standard sources traceable to synchrotron radiation.

The spectral irradiance calibration of tungsten strip and spiral filament lamps applying synchrotron radiation revealed that the spectral irradiance in the wavelength range from 280 to 400 nm can be well approximated by blackbody radiation according to Planck's law. Consequently, the spectral irradiance of the filament lamp can then be described by an effective irradiance temperature, which would be beneficial for practical measurements. Including the emissivity of tungsten into the approximation, the model can be expanded to visible and near-infrared wavelength regions.