Use Of Commercial Components Research Articles

Non-contact characterization of compound optical elements using reflectance confocal microscopy, low-coherence interferometry, and computational ray-tracing

Advances in microscopy have enabled us to see at unprecedented depths and resolutions, even breaking the diffraction-limit by several fold. These improvements have come at the expense of system complexity with microscopes routinely employing multiple objective lenses and custom optical relays. Optimal system design is paramount for imaging performance, but research systems are limited by the use of commercial components because optical prescriptions are often inaccessible. System performance can be further degraded when these components are implemented in nonstandard configurations outside of manufacturer specifications. Here, we describe a method for characterization of compound optical elements including curvatures, material and air-gap thicknesses, and glass types. We present validation data for doublets and a commercial broadband scan lens. Our method is both non-contact and non-destructive, and we believe it addresses a unique gap in optical design that may be extended to broad applications in both research and industrial manufacturing.

An amplifier for VUV photomultiplier operating in cryogenic environment

We present the characterisation of an amplifier potentially interesting for noble liquid detectors. The design has been conceived considering the requirements of low power consumption (less than 30mW), low noise, amplification factor of 10 at 100MHz and use of commercial components. The amplifier has been integrated onto an electronic board with a voltage divider to operate an Hamamatsu R11410 photomultiplier tube (used in XENON1T, Aprile et al. (2014) [1] dark matter experiment).

Analysis of a Solid Oxide Fuel Cell System with Low Temperature Anode Off-Gas Recirculation

The daily growing global energy consumption has to be provided in the future by technologies which emit increasingly less greenhouse gases. This requires highly efficient energy systems. Methane fueled SOFC systems are already able to produce electricity with an efficiency up to 60 %. Through the combined use of produced electricity and thermal energy the overall efficiency can be above 90 %. One possibility for a further improvement of the electrical efficiency is the implementation of an anode off-gas recirculation loop. Challenging is the high anode off-gas temperature of at least 700 °C, which prohibits the use of commercial components. Therefore, the use of ejectors and blowers with or without anode off-gas cooling are discussed in literature. At Forschungszentrum Jülich an anode off-gas recirculation loop operating at temperatures up to 200 °C is favored. To analyze the effect of anode off-gas recirculation, a dynamical model of the system including the recirculation loop was implemented in Matlab/Simulink®. The results show, that the recirculation rate has a huge effect on the electrical efficiency (both positive and negative). In principle, at constant current density high recirculation rates decrease the cell voltage and increase the power consumption of the recirculation blower. Therefore, the highest electrical efficiency can be reached with high systems fuel utilizations, low recirculation rates and in consequence high stack fuel utilizations. On the other hand less amount of steam is available for the reforming reaction at low recirculation rates, therefore the minimum recirculation rate is determined by the formation of carbon. An optimal operation range to avoid carbon formation and to ensure a high electrical efficiency requires recirculation rates between 65 and 70 % and system fuel utilizations above 90 %. This leads to acceptable stack fuel utilizations in the range of 70 to 75 % and electrical efficiencies above 60 %.

ARCADE small-scale docking mechanism for micro-satellites

The development of on-orbit autonomous rendezvous and docking (ARD) capabilities represents a key point for a number of appealing mission scenarios that include activities of on-orbit servicing, automated assembly of modular structures and active debris removal. As of today, especially in the field of micro-satellites ARD, many fundamental technologies are still missing or require further developments and micro-gravity testing.In this framework, the University of Padova, Centre of Studies and Activities for Space (CISAS), developed the Autonomous Rendezvous Control and Docking Experiment (ARCADE), a technology demonstrator intended to fly aboard a BEXUS stratospheric balloon. The goal was to design, build and test, in critical environment conditions, a proximity relative navigation system, a custom-made reaction wheel and a small-size docking mechanism.The ARCADE docking mechanism was designed against a comprehensive set of requirements and it can be classified as small-scale, central, gender mating and unpressurized. The large use of commercial components makes it low-cost and simple to be manufactured. Last, it features a good tolerance to off-nominal docking conditions and a by-design soft docking capability.The final design was extensively verified to be compliant with its requirements by means of numerical simulations and physical testing. In detail, the dynamic behaviour of the mechanism in both nominal and off-nominal conditions was assessed with the multibody dynamics analysis software MD ADAMS 2010 and functional tests were carried out within the fully integrated ARCADE experiment to ensure the docking system efficacy and to highlight possible issues. The most relevant results of the study will be presented and discussed in conclusion to this paper.

A very high performance stabilization system for large mass bolometerexperiments

Abstract CUORE is a large mass bolometric experiment, composed of 988 crystals, under construction in Hall A of the Gran Sasso Underground Laboratories (LNGS). Its main aim is the study of neutrinoless double beta decay of 130Te. Each bolometer is a 760 g crystal of Tellurium dioxide on which a Nuclear Transmutation Doped Ge thermistor, Ge NTD, is glued with proper thermal contact. The stability of the system is mandatory over many years of data taking. To accomplish this requirement a heating resistor is glued on each detector across which a voltage pulse can be injected at will, to develop a known calibrated heating power. We present the design solution for a pulse generator system to be used for the injection of such a small and short voltage pulse across the heaters. This system is composed by different custom PCB boards each of them having multi-channel independent outputs completely remotely programmable from the acquisition system, in pulse width and amplitude, through an on-board ARM7 microcontroller. Pulse amplitudes must be selectable, in order to handle each detector on its full dynamic range. The resolution of the output voltage is 12 bits over 10 V range. An additional 4 steps programmable voltage attenuator is added at every output. The width of any pulse can range from 100 μ s to 25.5 ms. The main features of the final system are: stability and precision in pulses generation (at the level of less than a ppm/°C), low cost (thanks to the use of commercial components) and compact implementation.

Total Ionizing Dose Mitigation by Means of Reconfigurable FPGA Computing

We present a novel design technique for hardening field programmable gate arrays (FPGAs) against total ionizing dose (TID). There is increasing use of commercial components in space technology and it is important to recognize that the space radiation environment poses the risk of permanent malfunction due to radiation. Therefore, the integrated circuits used for spacecraft electronics must be resistant to radiation. The amount of threshold voltage shift in MOS devices caused by ionizing radiation is strongly dependant on the bias voltage applied to the gate terminal during radiation. The threshold voltage shift is much less severe under the influence of ionizing radiation if the gate voltage is 0 V with respect to the device substrate. We have direct control of the bias voltage applied to the gate terminal, and therefore can control the rate of threshold voltage shift in the MOS device. Digital electronic circuits can be hardened against TID effects by selectively applying modular redundancy. By applying Double Modular redundancy, hence, activating one module while the other is inactivated, allows the inactive modules to stop degrading during its ldquooffrdquo cycle. It is shown by means of experimentation that this new design technique provides greatly improved TID tolerance for field programmable gate arrays by means of reconfigurable computing.

A low-cost, ultra-fast and low-noise preamplifier for micro channel plates

A compact, low-cost, ultra fast, low distortion and low noise preamplifier suitable for data-acquisition applications utilization micro channel plate (MCP) detectors has been built with a new monolithic integrated circuit amplifier in two stages. The gain, bandwidth and noise are optimized to the MCP performance in order to achieve the best rise time, response and stability with minimal jitter. The use of commercial components makes this instrument very low in cost and easy to build.