Optical Inter-Satellite Link over Low Earth Orbit: Enhanced Performance

Space communication systems are traditionally operated with microwave in satellite-to-satellite links. Now, more efficient and reliable operation is required, which lead to use optical links for Inter Satellite Links (ISLs). This paper investigates the system performance of an optical ISL proposed between satellites over Low Earth Orbit (LEO). In this study, the proposed link is simulated to obtain a maximum bit rate and minimum bit error rate (BER) over different links distances. The system performance is improved by investigating its dependency on the photo detector type, operating wavelength, transmitted optical power, RZ and NRZ schemes. Our work results that best Q- factor are approximately 40 leading to a minimum BER for the LEO orbit, at 600 km when utilizing an APD. While at our investigation of the system performance at visible light bands, it is found that Q-factor will be approximately 60 achieving minimum BER with neglecting the eye-safety precautions in addition to the ability to transmit 2 Gbps at 10−9 BER within many bands.

The energy spectrum of cosmic rays beyond the turn-down around $$\varvec{10^{17}}$$ eV as measured with the surface detector of the Pierre Auger Observatory

We present a measurement of the cosmic-ray spectrum above 100 PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750 m. An inflection of the spectrum is observed, confirming the presence of the so-called second-knee feature. The spectrum is then combined with that of the 1500 m array to produce a single measurement of the flux, linking this spectral feature with the three additional breaks at the highest energies. The combined spectrum, with an energy scale set calorimetrically via fluorescence telescopes and using a single detector type, results in the most statistically and systematically precise measurement of spectral breaks yet obtained. These measurements are critical for furthering our understanding of the highest energy cosmic rays.

Cosmic-ray-related Signals from Detectors in Space: The Spitzer/IRAC Si:As IBC Devices

We evaluate the hit rate of cosmic rays and their daughter particles on the Si:As IBC detectors in the IRAC instrument on the Spitzer Space Telescope. The hit rate follows the ambient proton flux closely, but the hits occur at more than twice the rate expected just from this flux. Toward large amplitudes, the size distribution of hits by single-charge particles (muons) follows the Landau Distribution. The amplitudes of the hits are distributed to well below the energy loss of a traditional “average minimum-ionizing proton” as a result of statistical fluctuations in the ionization loss within the detectors. Nonetheless, hits with amplitudes less than a few hundred electrons are rare; this places nearly all hits in an amplitude range that is readily identified given the read noises of modern solid-state detectors. The spread of individual hits over multiple pixels is dominated by geometric effects, i.e., the range of incident angles, but shows a modest excess probably due to: (1) showering and scattering of particles; (2) the energy imparted on the ionization products by the energetic protons; and (3) interpixel capacitance. Although this study is focused on a specific detector type, it should have general application to operation of modern solid-state detectors in space.

Methods used for Gas Tightness Test and percent Oxygen Monitoring of the NSW Micromegas Detectors of LHC-ATLAS Experiment

In the frame of the LHC-ATLAS Upgrade of phase I, the New Small Wheel detector system is under integration and commissioning at CERN Laboratories. One of the detector type, the Micromegas detectors, during their integration are tested in several stages for gas tightness validation. In particular, the novel method we are using for the gas tightness test, that we called “Flow Rate Loss”, has been realized in several semi-automatic fixed, portable and stand-alone setups for testing either the Micromegas Quads or the final Double Wedges. The obtained measurements up-to-date are presented as well as their obtained statistical distribution. Additionally, during the performance evaluation of the detectors, a percent oxygen monitoring is also performed in 24-hour base. The methods and techniques we developed and used are presented analytically in this work.

P Pemanfaatan Arduino Uno sebagai Alat Ukur Offset Voltage pada Infra Red Detector type TO39 dengan pembanding alat ukur DMM

The infrared detector (or IR detector) is an optoelectronic component and represents the core element of gas analyzers, flame sensors, devices of spectral analysis, as well as non-contact temperature measurement. pyroelectric infrared detectors work with stabilization time in a wide operating temperature range (-55 ... 85) °C, capable of measuring the slightest amounts of infrared radiation (as little as a fraction of a nW) with wavelengths between 1 µm and > 25 µm. The difference of the good pyroelectric or No good (NG) devices shown by graph of voltage offset operating that can check by manual using Digital Multi Meter or semi auto by using microcontroller One of importance measuring of IRD sensors is Offset Voltage, stabilization of offset voltage indicate the sensor is stable with certain level value. Stabilization value measurement during measuring time means the average value not so much different with fluctuation value. 10 bit ADC on Atmega 328 that main microcontroller on Arduino Uno is capable to measure the Offset Voltage of IRD sensor and check the measurement values is within specification of IRD sensor.

A Bi-Spectral Microbolometer Sensor for Wildfire Measurement

This study describes the development of a prototype bi-spectral microbolometer sensor system designed explicitly for radiometric measurement and characterization of wildfire mid- and long-wave infrared radiances. The system is tested experimentally over moderate-scale experimental burns coincident with FLIR reference imagery. Statistical comparison of the fire radiative power (FRP; W) retrievals suggest that this novel system is highly reliable for use in collecting radiometric measurements of biomass burning. As such, this study provides clear experimental evidence that mid-wave infrared microbolometers are capable of collecting FRP measurements. Furthermore, given the low resource nature of this detector type, it presents a suitable option for monitoring wildfire behaviour from low resource platforms such as unmanned aerial vehicles (UAVs) or nanosats.

Radioactivity of Some Soils in the University of Tikrit, Iraq, college of Education for Girls using Solid-State Nuclear Track Detector type CR-39

In this research radon concentrations in soil samples of some sites of the College of Education for Women, University of Tikrit, were measured using CR-39 nuclear impact detector. Soil samples were prepared according to classical protocols whereby they were irradiated for a period of 65 days in propagation chambers chemically treated and subjected to optical microscopy to calculate nuclear effects. The results show differences in the concentrations of radon gas in the samples collected from different sites ranging between a lowest value in the location of the department of English and a highest value of in the location of the cafeteria of College compared to the radiation background of due to the geological factors that depend on the type and specifications of the soil, the amount of gases emitted from the soil, the amount of the emergence of radon from the granules of the soil and its spread through the pores of the soil to the outside.

Measuring Uranium Concentrations in Soil Samples of Midland Refineries Company - Doura - Baghdad – Iraq

In this study, the CR-39 detector technique was used, to estimate the uranium concentration from the soil in midland refineries Company (Doura refine (, Baghdad, Iraq. Uranium concentrations in soil samples have been measured using solid state nuclear track detector type CR-39. Nine soil samples were collected from different areas within the Doura refinery and other soil samples were collected form Abu Tayara Street and ALshortaa District outside the refinery for comparison. The results showed variable values for uranium concentrations. The average value of uranium concentration was found to be 0.37 ppm in doura refinery. For areas outside the refinery, the concentration of uranium was 0.008 ppm. These results were less than the global limit.

MEASUREMENT OF CARBON MONOXIDE EMISSIONS FROM VEHICLES EXHAUST PIPE USING PORTABLE GAS DETECTOR

Carbon monoxide (CO) contamination represents a major global concern. This study aimed to detect the concentration of CO, emitted from various vehicles exhausters which are important contributors in deteriorating air quality. The data was collected throughout the heavy parking period at Al- Jadyria campus in Baghdad University. The vehicles were classified into two main groups according to the type of gasoline they are filled with; including premium leaded and leaded free gasoline (PLG and LFG respectively), as well as engine size, odometer, brand and model. Seven low duty vehicles for each engine size (<1.6 to >2.0) liter were selected randomly. A portable gas detector type (Altair® 4X) was used to measure exhausted emission of CO during idle mode. The results showed that high mean levels of CO (206.111–939) ppm were observed within vehicles filled with PLG. In contrast, the vehicles filled with LFG had been detected with an observable decline (9.5714–21.5714) ppm. Also, a significant difference in gas concentration between fuel types was observed within various engine groups. This study recommended controlling these emissions and raising the concern of the government about the gasoline quality due to their adverse impact on human health and environment.