In-situ, low dose rate, total ionising dose test of the cooling performance of a thermoelectric module
This work presents and discusses the design and fully automated total ionising dose test of a thermoelectric cooling module. The goal was to develop a reliable test method which can be used to measure potential total ionising dose induced degradation of the cooling performance and demonstrate this method in a long term, low dose rate experiment. Details of the tested hardware and fully automated test system are published in this work, including preliminary test results and lessons learned.
MEASUREMENT OF RADIATION EFFECTS ON ACTIVE AND PASSIVE OPTICAL FIBER COMPONENTS
The present contribution is focused on the measurement of the degradation induced in the case of two splitters and two attenuators used in optical fiber communication systems, under gamma and neutron irradiation. The measurements were carried out at specific wavelengths ( � = 1310 nm and � = 1550 nm) or over a spectral band (� = 1510 - 1620 nm), in order to evaluate the wavelength dependence of the phenomena. These components were also tested as it concerns the changes of the polarization state of optical radiation they guide. A second investigation was performed on the degradation of the operational parameters for a laser diode driving circuit and a Peltier TEC (thermoelectric cooler), under gamma- ray, neutron and electron beam irradiation. No significant changes were noticed in the spectral transmission of the two passive components, but the degradation of the light polarization parameters was a significant one under gamma- ray irradiation. In the case of the laser diode drivers a drop of 80 % of the laser diode optical power and the embedded photodiode responsivity was observed under gamma-ray and neutron irradiation.
CAUSES OF FLUCTUATIONS IN R&D EXPENDITURES A QUANTITATIVE ANALYSIS
Introduction 124 The stylised facts of R&D in OECD economies 124 The determinants of business R&D expenditures 127 Modelling R&D expenditures 130 Conclusion 135 Bibliography 137 Annex: The model 138