Measurements Of Radiation Research Articles

Improvement Method of Antenna Negative Sidelobes on Cross Beam Correlation Microwave Radiometer

A weighting method is proposed for the correlation radiation measurement system based on Mills cross array. The Mills cross array achieves high spatial resolution by the product of two orthogonal fan beams. However, the product power pattern of the Mills cross array lacks a square operation, resulting in sidelobe deterioration and the presence of negative sidelobes. Therefore, a window function is necessary to improve beam performance. However, because of the negative sidelobes, the antenna array is sensitive to the weighting function, and common window functions such as Hanning and Hamming are not suitable for achieving optimal antenna performance. A weighting method is proposed to fully utilize the feature that the received energy of positive and negative sidelobes cancel each other out and to reduce the influence of antenna sidelobe errors in radiation measurement. Such a weighting function can be obtained by combining the combined cosine window function with the existing particle swarm optimization (PSO). The optimized window function is evaluated through numerical simulation and compared with the typical window function weighting results. The results show that this weighting method can minimize the impact of negative sidelobes and reduce the loss of spatial resolution.

The Determination and evaluation of trace elements in the blood of radiography workers using graphite furnace atomic absorption spectrometry

This study aimed to evaluate the potentially toxic effects of trace elements in the blood of Iraqi medical radiography workers by analyzing them through GF-AAS. The study involved 50 male blood radiography workers from the medical imaging field at Al-Shatrah General Hospital in Thi-Qar City, Iraq. All workers were aged between 35-50 years and had worked for less than 10 years. The study compared these workers with 50 healthy men. The study found a significant increase in the levels of Cu, Pb, Cd, and Ca among radiography workers compared to the healthy control group, while Zn and Se levels decreased significantly. Moreover, Specificity and confidence interval (95%) were estimated via the receiver operating characteristic curve (ROC). The study provided conclusive evidence of disturbances in the levels of trace elements in the blood of radiographer workers, which makes them more susceptible to many diseases because of their radiation exposure. which portends the more preventive measures of radiation. The linear range of Cd, Cu, Zn, Se and Pb in human serum were obtained 0.2-6.0 µg dL-1, 6.0-200 µg dL-1, 8.0-200 µg dL-1, 10-250 µg dL-1, 4-120 µg dL-1 by GF-AAS after dilution samples with DW up to 20 (n=10, RSD< 5%).

Scattered high-energy synchrotron radiation at theKARA visible-light diagnostic beamline.

To characterize an electron beam, visible synchrotron light is often used and dedicated beamlines at synchrotron sources are becoming a more common feature as instruments and methods for the diagnostics are, along with the accelerators, further developed. At KARA (Karlsruhe Research Accelerator), such a beamline exists and is based on a typical infrared/visible-light configuration. From experience at such beamlines no significant radiation was expected (dose rates larger than 0.5 µSv h-1). This was found not to be the case and a higher dose was measured which fortunately could be shielded to an acceptable level with 0.3 mm of aluminium foil or 2.0 mm of Pyrex glass. The presence of this radiation led to further investigation by both experiment and calculation. A custom setup using a silicon drift detector for energy-dispersive spectroscopy (Ketek GmbH) and attenuation experiments showed the radiation to be predominantly copper K-shell fluorescence and is confirmed by calculation. The measurement of secondary radiation from scattering of synchrotron and other radiation, and its calculation, is important for radiation protection, and, although a lot of experience exists and methods for radiation protection are well established, changes in machine, beamlines and experiments mean a constant appraisal is needed.

Перенос аврорального километрового радиоизлучения посредством каналов с пониженной плотностью на границе плазмосферы

We present the results of Auroral Kilometric Radiation (AKR) measurements near the plasmapause on the ERG (Arase) satellite. The apogee of the satellite's orbit is located near the ecliptic plane, at latitudes ±30°. According to the generally accepted point of view, AKR observation is impossible in this region since it is shielded by the plasmasphere. Simultaneous measurements of AKR and local plasma density made it possible to determine that AKR in near-equatorial regions occur in plasma channels — density inhomogeneities elongated along magnetic field lines. AKR from sources located in the auroral magnetosphere is transferred by these channels to the equatorial region. This work analyzes the conditions for the capture and propagation of AKR in low plasma density channels. In the geometrical optics approximation, we have simulated the conditions for the radiation capture and propagation. The calculation results show that the proposed scheme for AKR capture into plasma channels can explain the measurement results — the radiation transfer from the auroral region to the near-equatorial region.

Transfer of auroral kilometric radiation through low-density channels at the boundary of plasmasphere

We present the results of Auroral Kilometric Radiation (AKR) measurements near the plasmapause on the ERG (Arase) satellite. The apogee of the satellite's orbit is located near the ecliptic plane, at latitudes ±30°. According to the generally accepted point of view, AKR observation is impossible in this region since it is shielded by the plasmasphere. Simultaneous measurements of AKR and local plasma density made it possible to determine that AKR in near-equatorial regions occur in plasma channels — density inhomogeneities elongated along magnetic field lines. AKR from sources located in the auroral magnetosphere is transferred by these channels to the equatorial region. This work analyzes the conditions for the capture and propagation of AKR in low plasma density channels. In the geometrical optics approximation, we have simulated the conditions for the radiation capture and propagation. The calculation results show that the proposed scheme for AKR capture into plasma channels can explain the measurement results — the radiation transfer from the auroral region to the near-equatorial region.

A new infrared radiation calibration method based on lens cover deduction of internal stray radiation

A new infrared radiation calibration method based on lens cover deduction of internal stray radiation is proposed to address the issue of grayscale deviation of infrared radiation measurement systems caused by environmental temperature changes, which leads to the failure of the traditional infrared radiation calibration method. Firstly, the influence of environmental temperature on the traditional radiation calibration was analyzed. Then, a mathematical model for infrared radiation calibration based on lens cover deducting internal stray radiation was established, and compared the environmental adaptability with the traditional radiation calibration. Finally, the experimental results show that this method has the ability to enhance the environmental adaptability of infrared radiation measurement systems, improve the accuracy of infrared radiation measurement, and especially for the optical system with high attenuation attenuator, the calibration coefficient can achieve the same environmental adaptability as that for the 100% transmittance attenuator. The environmental adaptability of the calibration coefficient is also greatly better than the traditional calibration for the 100% transmittance attenuator.

Evaluation of the reduction of radiation dose received by pediatric patients in new-generation biplane angiocardiography: Randomized controlled study

ObjectiveWe aimed to evaluate the safety and efficacy of radiation dose reduction with a new-generation biplane angiocardiography system in patients undergoing transcatheter isolated patent ductus arteriosus (PDA) closure. Materials and methodsFifty pediatric patients who underwent transcatheter PDA closure were randomly divided into two groups as normal radiation dose and low dose. Patients who required additional procedures other than PDA closure were excluded. PDA closure was performed according to the angiographic measurement of the defect. After the procedure, age, weight, sex, PDA measurements, and radiation measurements such as dose-area product (DAP, Gy.cm2) and air kerma (AK, mGy) were compared between the groups. ResultsThere was no statistically significant difference between the groups in age, sex, weight, PDA diameter, PDA type, device used, and device diameter (p > 0.05). While there was no statistically significant difference between the groups in terms of cine recording, number of recorded images, and fluoroscopy time (p > 0.05), there was a statistically significant difference between the total DAP, cine and fluoroscopy DAP, total AK, frontal and lateral tube AK, and DAP/kg (mGy.m2/kg) measurements (p < 0.05). ConclusionTranscatheter PDA closure with a low radiation dose is as effective as that with a normal radiation dose. The radiation dose received by the patient during the procedure was significantly reduced. With the vision provided by this study, it seems possible to work with a low radiation dose in other groups of patients.

Physical dose validation of dynamic treatment for Gamma Knife radiosurgery.

Dynamic treatment in Gamma Knife (GK) radiosurgery systems delivers radiation continuously with couch movement, as opposed to stationary step-and-shoot treatment where radiation is paused when moving between isocenters. Previous studies have shown the potential for dynamic GK treatment to give faster treatment times and improved dose conformity and homogeneity. However, these studies focused only on computational simulations and lack physicalvalidation. This study aims conduct dynamic treatment dosimetric validation with physical experimental measurements. The experiments aim to (1) address assumptions made with computational studies, such as the validity of treating a continuous path as discretised points, (2) investigate uncertainties in translating computed plans to actual treatment, and (3) determine ideal treatment planning parameters, such as interval distance for the path discretization, collimator change limitations, and minimum isocenter treatmenttimes. This study uses a GK ICON treatment delivery machine, and a motion phantom custom-made to attach to the machine's mask adapter and move in 1D superior-inferior motion. Phantom positioning is first verified through comparisons against couch motion and computed doses. For dynamic treatment experiments, the phantom is moved through a program that first reads the desired treatment plan isocenters' position, time, and collimator sizes, then carries out the motion continuously while the treatment machine delivers radiation. Measurements are done with increasing levels of complexity: varying speed, varying collimator sizes, varying both speed and collimator sizes, then extends the same measurements to simulated 2D motion by combining phantom and couch motion. Dose comparisons between phantom motion radiation measurements and either couch motion measurements or dose calculations are analyzed with 2 mm/2% and 1 mm/2% gamma indices, using both local and global gamma indexcalculations. Phantom positional experiments show a high accuracy, with global gamma indices for all dose comparisons 99%. Discretization level to approximate continuous path as discrete points show the good dose matches with dose calculations when using 1 and 2-mm gaps. Complex 1D motion, including varying speed, collimator sizes, or both, as well as 2D motion with the same complexities, all show good dose matches with dose calculations: the scores are 92.0% for the strictest 1 mm/2% local gamma index calculation, 99.8% for 2 mm/2% local gamma index, and 97.0% for all global gamma indices. Five simulated 2D treatments with optimized plans scored highly as well, with all gamma index scores 95.3% when compared to stationary treatment, and scores 97.9% when compared to plan calculateddose. Dynamic treatment computational studies are validated, with dynamic treatment shown to be physically feasible and deliverable with high accuracy. A 2-mm discretization level in treatment planning is proposed as the best option for shorter dose calculation times while maintaining dose accuracy. Our experimental method enables dynamic treatment measurements using the existing clinical workflow, which may be replicated in other centers, and future studies may include 2D or 3D motion experiments, or planning studies to further quantify potential indication-specificbenefits.

Comprehensive optical and thermal investigation of optimal near-infrared absorption enhancement of nano-patterned aluminum

Compelling electromagnetic (EM) properties, such as tight EM-confinement and fabrication-compatible architectures, propel the importance of metal-based nanophotonics in small-footprint devices, such as highly efficient optical absorbers. Here, we focus on boosting the absorption of optically thick bulk Aluminum (Al), the most abundant metal, solely by corrugating its surface periodically. Application-oriented, we utilize the simplest one-dimensional (1D) rectangular-grating pattern that can be remotely engraved on a large scale, e.g., using femtosecond pulsed lasers. We devise four designs for various utilizations optimized for perfect absorption around the application-abundant 1.06μm wavelength under transverse electric (TE), transverse magnetic (TM), and unpolarized (denoted TEM) irradiations. Lacking attractive plasmonic confinement properties, the s-polarization is considered electromagnetically “degenerate” to the p-polarization case, making it rarely explored in the literature of 1D-grating architectures. Nevertheless, we reveal that perfect s-polarized absorption is also attainable in such designs without adding extra layers. The designs’ performance, properties, limitations, and the propelling electromagnetic physics are theoretically and numerically discussed in-depth. A large-area sample of the TEM-optimized design was fabricated, facilitating uniquely extensive optical and radiative heating experimental investigation with realistic near-to-normal Gaussian-beam incidence. The absorption enhancement derived from wideband and single-frequency optical and radiative heating measurements agree well, also with the numerical simulations. Despite fabrication-derived thickness deviation, the design experimentally showed a 9.6-(TE), 6-(TM), and 7.8-(TEM) fold absorption enhancement over bulk Al. Considering the one-dimensional-patterning simplicity and its large-area fabrication compatibility, it is noteworthy and pioneering, particularly for the challenging s-polarization case. We also study a polarization-sensitive diffused reflection scattering pattern, evidently postulated to result from resonated surface roughness, highlighting the importance of radiative heating measurements. The elaborated original findings and methods are highly applicable alongside the prevalent material and spectrum.

Wavelength measurement of narrowband terahertz radiation using a diffraction grating

We propose a reflective binary amplitude grating-based setup for determining the frequency of narrowband terahertz radiation. Theoretical analysis was conducted on transmissive and reflective configurations utilizing binary and phase gratings. Simulations were performed to determine the parameters of metallic diffraction gratings with millimeter-scale constants, which were produced using laser cutting techniques. Our implementation consists of a cost effective and easy-to-implement setup that operates within the 0.15–1 THz range. The grating is installed on a rotary stage. The experimental results obtained align closely with the theoretical calculations. By understanding the setup parameters and the angle of the 1st diffraction order, we could calculate the frequency of the unknown radiation. The relative error in determining the frequency was less than 2%.

Effect of Radiation Position of Photon Beam at Axis Point and Field Edge on Absorbed Dose on Linear Accelerator (Linac)

&#x0D; &#x0D; &#x0D; &#x0D; Radiotherapy is a medical treatment that uses ionizing radiation to kill cancer cells using a Linear Accelerator (Linac). One of the errors in radiotherapy irradiation can occur because the radiation beam that comes out is not in accordance with the planning. Therefore, radiation absorbed dose measurement is needed to carry out as a quality assurance to control the accuracy and suitability of the dose to be received by the patient by following the standards of the Technical Report Series (TRS) 398. This study was conducted at Radiotherapy Installation of RSUD A.W. Sjahranie Samarinda. In the measurement of radiation absorbed dose, the detector was placed in the center of the water phantom with a certain depth and placed in an axis position perpendicular to the radiation source. The detector is not only placed in the axis position, but also placed on the 4 edges of the field with the aim of knowing the effect of the location of the detector on the absorbed dose on the Linac plane. Medium water phantom, Farmer type ionization detector with a depth of 10 cm, and radiation source distance to the phantom surface of 100 cm were applied in this study. The measurement deviation results at the axis position and 4 field edges are 0.01%, 0.06%, 0.03%, 0.05%, and 0.05%. These values are within the tolerance limits written in the IAEA TRS 398 protocol, which is ± 2%. This states that the radiation absorbed dose by the water phantom is homogeneous in all directions.&#x0D; &#x0D; &#x0D; &#x0D;

A Low-Power Optical Sensor With Dynamically Adjustable Field of View for Photosynthetically Active Radiation (PAR) Measurement

A Low-Power Optical Sensor With Dynamically Adjustable Field of View for Photosynthetically Active Radiation (PAR) Measurement

The Physics behind Precipitation Onset Bias in CMIP6 Models: The Pseudo-Entrainment Diagnostic and Trade-Offs between Lapse Rate and Humidity

Abstract Conditional instability and the buoyancy of plumes drive moist convection but have a variety of representations in model convective schemes. Vertical thermodynamic structure information from Atmospheric Radiation Measurement (ARM) sites and reanalysis (ERA5), satellite-derived precipitation (TRMM3b42), and diagnostics relevant for plume buoyancy are used to assess climate models. Previous work has shown that CMIP6 models represent moist convective processes more accurately than their CMIP5 counterparts. However, certain biases in convective onset remain pervasive among generations of CMIP modeling efforts. We diagnose these biases in a cohort of nine CMIP6 models with subdaily output, assessing conditional instability in profiles of equivalent potential temperature, θe, and saturation equivalent potential temperature, θes, in comparison to a plume model with different mixing assumptions. Most models capture qualitative aspects of the θes vertical structure, including a substantial decrease with height in the lower free troposphere associated with the entrainment of subsaturated air. We define a “pseudo-entrainment” diagnostic that combines subsaturation and a θes measure of conditional instability similar to what entrainment would produce under the small-buoyancy approximation. This captures the trade-off between larger θes lapse rates (entrainment of dry air) and small subsaturation (permits positive buoyancy despite high entrainment). This pseudo-entrainment diagnostic is also a reasonable indicator of the critical value of integrated buoyancy for precipitation onset. Models with poor θe/θes structure (those using variants of the Tiedtke scheme) or low entrainment runs of CAM5, and models with low subsaturation, such as NASA-GISS, lie outside the observational range in this diagnostic.

Measurement of radiation induced attenuation in irradiated active fibers using optical frequency domain reflectometry

Radiation induced attenuation (RIA) is a major factor affecting the performance of fiber laser systems operated in adverse environments. To investigate the output characteristics of lasers with irradiated active fibers, measurement of detailed RIA profiles is required. Here, a novel method is proposed to explore the attenuation characteristics of irradiated active fibers using optical frequency domain reflectometry (OFDR), which enables propagation loss measurement by acquiring the spatial-resolved backscattered optical signals. With this technique, the RIA data of Yb-doped fibers (YDFs) under uniform radiation is derived by linear fitting of the OFDR traces. And, conventional optical transmission (OT) method is also exploited for comparison. Analysis show that the measured results of the two approaches are consistent. Then, the capability of OFDR is further verified for non-uniform RIA profile measurement of YDFs. For a pump bleached YDF, an upward parabolic RIA profile is attained by taking derivative of the smoothed polynomial fitting of the OFDR trace. Finally, the impacts of RIA profile on the output characteristics of Yb-doped fiber lasers are examined theoretically with a multiphysics thermal model, further validating the necessity of RIA profile measurement.

Prelaunch Spectral Characterization of the Operational Land Imager-2

The Landsat-9 satellite, launched in September 2021, carries the Operational Land Imager-2 (OLI-2) as one of its payloads. This instrument is a clone of the Landsat-8 OLI and its mission is to continue the operational land imaging of the Landsat program. The OLI-2 instrument is not significantly different from OLI though the instrument-level pre-launch spectral characterization process was much improved. The focal plane modules used on OLI-2 were manufactured as spares for OLI and much of the spectral characterization of the components was performed for OLI. However, while the spectral response of the fully assembled OLI was characterized by a double monochromator system, the OLI-2 spectral characterization made use of the Goddard Laser for Absolute Measurement of Radiance (GLAMR). GLAMR is a system of tunable lasers that cover 350–2500 nm which are fiber-coupled to a 30 in integrating sphere permanently monitored by NIST-traceable radiometers. GLAMR allowed the spectral characterization of every detector of the OLI-2 focal plane in nominal imaging conditions. The spectral performance of the OLI-2 was, in general, much better than requirements. The final relative spectral responses (RSRs) represent the best characterization any Landsat instrument spectral response. This paper will cover the results of the spectral characterization from the component-level to the instrument-level of the Landsat-9 OLI-2.

Resilient design in nuclear energy: Critical lessons from a cross-disciplinary analysis of the Fukushima Dai-ichi nuclear accident

This paper presents a multidisciplinary analysis of the Fukushima Dai-ichi Nuclear Power Plant accident. Along with the latest observations and simulation studies, we synthesize the time-series and event progressions during the accident across multiple disciplines, including in-plant physics and engineering systems, operators' actions, emergency responses, meteorology, radionuclide release and transport, land contamination, and health impacts. We identify three key factors that exacerbated the consequences of the accident: (1) the failure of Unit 2 containment venting, (2) the insufficient integration of radiation measurements and meteorology data in the evacuation strategy, and (3) the limited risk assessment and emergency preparedness. We conclude with new research and development directions to improve the resilience of nuclear energy systems and communities, including (1) meteorology-informed proactive venting, (2) machine learning-enabled adaptive evacuation zones, and (3) comprehensive risk-informed emergency planning while leveraging the experience from responses to other disasters.

Comparative radiative property measurements of single biomass and coal particles burning at high reactor temperatures

This research measured the emissivity, temperature and soot loading of pulverized bituminous coal and three types of renewable biomass. Combustion occurred in a laboratory-scale drop tube furnace (DTF), where the fuels experienced high heating rates and ignited and burned in two distinct phases: devolatilization accompanied by volatile matter combustion in envelope flames, and sequential combustion of the char residues. Multi-wavelength spectrometry was used to concurrently determine the emissivity and the temperature of burning particles at discrete points in their history. Three-wavelength pyrometry was used to obtain entire temperature-time histories, and high-speed photography was used to provide both visual observations of phenomena and to obtain two-dimensional temperature distributions. Results showed that soot in volatile matter flames of burning single particles of the bituminous coal and of the three types of torrefied biomass had spectral emissivities in the range of 0.03–0.10, in the wavelength domain of 600–1000 nm. Emissivities were nearly constant with wavelength, i.e., soot mantles in these flames radiated as graybodies. Spectral emissivities of the chars of the bituminous coal and the three types of torrefied biomass were in the range of 0.29–0.5 and varied with wavelength, i.e., they radiated as non-graybodies. The highest measured temperatures of soot in volatile flames for all fuels were between 2150 and 2360 K and maximum temperatures of chars were between 1700 and 2000 K, based on the three measurement techniques. The graybody assumption caused negligible (± 10 K) deviations in volatile matter flame temperatures; however, it caused significant deviations (± 20–100 K) in char temperatures. Envelope flame diameters of torrefied biomass particles were larger than those of coal. To the contrary, soot volume fractions in the envelope flames of coal particles were found to be higher than those in biomass particle flames. Finally, the soot volume fractions in the flames of these fuels were inversely proportional to particle size.

Characterization of human extreme heat exposure using an outdoor thermal manikin

Extreme heat is a current and growing global health concern. Current heat exposure models include meteorological and human factors that dictate heat stress, comfort, and risk of illness. However, radiation models simplify the human body to a cylinder, while convection ones provide conflicting predictions. To address these issues, we introduce a new method to characterize human exposure to extreme heat with unprecedented detail. We measure heat loads on 35 body surface zones using an outdoor thermal manikin (“ANDI”) alongside an ultrasonic anemometer array and integral radiation measurements (IRM). We show that regardless of body orientation, IRM and ANDI agree even under high solar conditions. Further, body parts can be treated as cylinders, even in highly turbulent flow. This geometry-rooted insight yields a whole-body convection correlation that resolves prior conflicts and is valid for diverse indoor and outdoor wind flows. Results will inform decision-making around heat protection, adaptation, and mitigation.

Improving the operational forecasts of outdoor Universal Thermal Climate Index with post-processing

The Universal Thermal Climate Index (UTCI) is a thermal comfort index that describes how the human body experiences ambient conditions. It has units of temperature and considers physiological aspects of the human body. It takes into account the effect of air temperature, humidity, wind, radiation, and clothes. It is increasingly used in many countries as a measure of thermal comfort for outdoor conditions, and its value is calculated as part of the operational meteorological forecast. At the same time, forecasts of outdoor UTCI tend to have a relatively large error caused by the error of meteorological forecasts. In Slovenia, there is a relatively dense network of meteorological stations. Crucially, at these stations, global solar radiation measurements are performed continuously, which makes estimating the actual value of the UTCI more accurate compared to the situation where no radiation measurements are available. We used seven years of measurements in hourly resolution from 42 stations to first verify the operational UTCI forecast for the first forecast day and, secondly, to try to improve the forecast via post-processing. We used two machine-learning methods, linear regression, and neural networks. Both methods have successfully reduced the error in the operational UTCI forecasts. Both methods reduced the daily mean error from about 2.6∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{\\circ }$$\\end{document}C to almost zero, while the daily mean absolute error decreased from 5∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{\\circ }$$\\end{document}C to 3∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{\\circ }$$\\end{document}C for the neural network and 3.5∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{\\circ }$$\\end{document}C for linear regression. Both methods, especially the neural network, also substantially reduced the dependence of the error on the time of the day.

First measurements with a Coherence Imaging Charge Exchange Recombination Spectroscopy (CICERS) diagnostic at Wendelstein 7-X

In this work, the Coherence Imaging Spectroscopy technique is exploited for active charge exchange radiation measurements to infer high spatial resolution 2D ion temperature ( Ti ) maps in the core region of Wendelstein 7-X plasmas. A synthetic model of the diagnostic is developed and used for the optimization of the hardware components for the expected ion temperatures ( Ti∼2 keV) prioritizing Ti measurements while also considering the ion velocity flow resolution. The experimental set-up is shown and the diagnostic calibration procedure for Ti measurements is introduced. A combination of both simulations and experimental calibrations enable high fidelity system group delay ( ∂ϕ∂λ ) characterization in the whole visible spectral range. Finally, the signal processing techniques applied to the diagnostic signal are introduced and first measurements of 2D Ti maps are presented and validated against standard Charge eXchange Recombination Spectroscopy Ti profiles, finding excellent agreement.