Preface

Julian Gröbner, Guest editor and chairman of the NEWRAD scientific committee Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center (PMOD/WRC) Dorfstrasse 33 7260 Davos Dorf, Switzerland The 14th International Conference on New Developments and Applications in Optical Radiometry (NEWRAD 2021) was organised by the National Institute for Standards and Technology (NIST), Boulder, United States and held online from 21 to 24 June 2021. Due to the COVID pandemic the original venue at Boulder in June 2020 had to be postponed and changed to a virtual event with a novel schedule consisting of pre-recorded talks and live sessions with the presenters to interact with conference attendees. The event was very well attended, notwithstanding the global participation with corresponding challenging time zones of the participants. A total of 274 registrations were received, with typically more than 100 attendees joining the online sessions. The NEWRAD scientific Committee would like to thank John Lehman and the whole local organising team for organising and holding this excellent event in the frame of these challenging conditions. 142 presentations were submitted, of which 48 were selected for oral talks, while the remaining submissions were presented as posters. Julian Gröbner, Guest editor and chairman of the NEWRAD scientific committee this title available in this pdf.

Leveraging chemical actinometry and optical radiometry to reduce uncertainty in photochemical research

Subtle aspects of illumination sources and their characterization methods can introduce significant uncertainty into the data gathered from light-activated experiments, limiting their reproducibility and technology transition. Degradation kinetics of methyl orange (MO) and carbamazepine (CM) under illumination with TiO₂ were used as a case study for investigating the role of incident photon flux on photocatalytic degradation rates. Valerophenone and ferrioxalate actinometry were paired with optical radiometry in three different illumination systems: xenon arc (XE), tungsten halogen (W-H), and UV fluorescent (UV-F). Degradation rate constants for MO and CM varied similarly among the three light systems as k W-H < kiv-F < kXE, implying the same relative photon flux emission by each light. However, the apparent relative photon flux emitted by the different lights varied depending on the light characterization method. This discrepancy is shown to be caused by the spectral distribution present in light emission profiles, as well as absorption behavior of chemical actinometers and optical sensors. Data and calculations for the determination of photon flux from chemical and calibrated optical light characterization is presented, allowing us to interpret photo-degradation rate constants as a function of incident photon flux. This approach enabled the derivation of a calibrated ‘rate-flux’ metric for evaluating and translating data from photocatalysis studies.

SI Traceable Solar Spectral Irradiance Measurement Based on a Quantum Benchmark: A Prototype Design

We propose a space benchmark sensor with onboard SI (Système International) traceability by means of quantum optical radiometry. Correlated photon pairs generated by spontaneous parametric down-conversion (SPDC) in nonlinear crystals are used to calibrate the absolute responsivity of a solar observing radiometer. The calibration is systematic, insensitive to degradation and independent of external radiometric standards. Solar spectral irradiance at 380–2500 nm is traceable to the photon rate and Planck’s constant with an expected uncertainty of about 0.35%. The principle of SPDC calibration and a prototype design of the solar radiometer are introduced. The uncertainty budget is analyzed in consideration of errors arising from calibration and observation modes.

Characterisation of the impact response of energetic materials: observation of a low-level reaction in 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105)

Time resolved and integrated diagnostics including high speed photography, mass and optical spectroscopy, and optical-radiometry used to study impact response of high explosives in far more detail than possible with conventional sensitiveness tests.

OPTIMIZATION ON WIRELESS POWER TRANSFER

Today, the limit of wireless devices lays in the way they powered. There has been a renewed focus on wireless power transmission technology due to its wide range of application in charging electronic devices such as mobile, MP3 player and household robots without a cord. Imagine a device that doesn't need a charger or even a battery, which instead gets power wirelessly over the air. To make such a device possible the transfer distance of currently known system have to be increased. The wireless power transfer can be optimized base on Friis equation. The Friis transmission equation is developed from principle of optical radiometry and scalar diffraction. Friis equation will gives the amount of power an antenna received under ideal conditions from another antenna.