Diagnostic Mirror Research Articles

Multi-staged ERO2.0 simulation of material erosion and deposition in recessed mirror assemblies in JET and ITER

The deposition/erosion on optical diagnostic components—mirrors—is a critical issue in reactor class devices with long-pulsed high fluence plasma operation. The paper presents results of the three-dimensional Monte–Carlo code ERO2.0 for two diagnostic aperture and first mirror geometries to be deployed in ITER, along with a separate simulation study that aims to replicate results from an experimental first-mirror study carried out on JET. Promisingly, very little plasma and impurity deposition on mirrors for the anticipated plasma durations is found in the ERO2.0 modelling taking into account the current ITER Research Plan and a material mix with beryllium first wall and a tungsten divertor. The post-mortem analysis of mirrors exposed during the experiment and the initial benchmarking efforts on the JET mirror experiment are also broadly consistent, increasing the confidence in predictions for ITER.

Multi-staged ERO2.0 simulation of material erosion and deposition in recessed ITER mirror assemblies

In reactor class devices, with long pulse, high fluence plasma operation and with diagnostic systems that cannot easily be maintained, a critical issue is the deposition/erosion of wall materials and its impact on key optical diagnostic components — mirrors. A workflow for recessed volume simulation was developed for the three-dimensional Monte-Carlo code ERO2.0 (Romazanov, 2020), consisting of multiple simulation stages starting from first wall erosion to more focussed volumes around the key components. This complex workflow has been found to be mandatory to have meaningful statistics of interaction processes on the mirror because the physical fluxes of particles into recessed volumes are extremely low compared to first wall fluxes, leading to unsatisfying statistics in the case of standard Monte-Carlo simulations. The workflow is introduced with the example of a diagnostic mirror assembly in equatorial port 12 behind panels 14 and 15 in the diagnostic first wall in ITER, assuming a beryllium first wall of the main vessel, a stainless steel mirror unit and two molybdenum mirrors embedded in a port plug for neutron shielding. The simulation case corresponds to an H-mode burning plasma case from SOLPS modelling, for which the incoming flux distributions of deuterium neutrals into the recessed volume were simulated by the neutrals transport code EIRENE.

Waxy Nodules: As a Cutaneous Diagnostic Mirror of Systemic Disease Mimicking Rheumatoid Arthritis.

Waxy Nodules: As a Cutaneous Diagnostic Mirror of Systemic Disease Mimicking Rheumatoid Arthritis.

The Prevalence Of Enamel Defects Among The Students Of Secondary School (Age 14-17) In Baghdad/Alrosafa

Aim of the study: To study the occurrence of enamel defects, the most common type and what gender is more affected on the students at the secondary school in Baghdad-Alrosafa.
 Materials and methods: Eight hundred and fifty students in the secondary school in Baghdad-Alrosafa were included in this study without any systemic disease with a 425 male and 425 female aging from 14 to 17 years old. A diagnostic instrument probe, mirror, gloves and tweezer were used. All students were examined clinically for the presence of enamel defect like enamel fluorosis, amelogenesis imperfecta, enamel erosion, abrasion and attrition. T-test was used for statistical analysis.
 Results: Results of the current study showed a high percentage of enamel defect occurring in females than in males and a high significant difference recorded at 17 years old in enamel fluorosis with an enamel attrition recording a higher percentage than other anomalies.
 Conclusion: conclusion of study is that the enamel defect occurs in females more than males and molar teeth have a higher prevalence than other teeth. Attrition recorded a higher percentage than other defects followed by enamel fluorosis and the lower one is amelogenesis imperfacta.

Analysis of cancer-related mutations in extracellular vesicles RNA by Droplet Digital™ PCR.

Extracellular vesicles (EVs) are taking their place as potential biomarkers in the field of liquid biopsy. In this study, EVs were isolated from plasma samples of 31 patients with colorectal cancer and melanoma via differential centrifugation and Droplet Digital™ PCR (Bio-Rad, CA, USA) was used to profile BRAF V600E/K, KRAS G12A/C/D/V and KRASG13D mutations from EV-derived cDNA. The concordance rates with corresponding tissue were 54%and 44% in the colorectal cancer and melanoma cohort, respectively. Two patients displayed mutations in EVs not previously detected in tissue as evidence for emerging molecular resistance to anti-EGFR and BRAF/MEK inhibitor therapy prior to radiological evidence of tumor progression. We concluded that EV-derived nucleic acids may provide clinically relevant diagnostic information and mirror evolution of the disease.

Deposition and Characterization of a Rhodium Thin Films with a Niobium Interlayer on a Molybdenum Mirror for ITER First-Mirror Application

Metallic mirrors are now essential components of the (International Thermonuclear Experiment Reactor) ITER plasma diagnostics system. The optical properties of the first mirror (FM) in the hostile ITER environment have adverse effects due to erosion and deposition owing to high energy charge exchange of neutral (CXN) particles, UV, X-ray, and gamma radiation. Molybdenum (Mo) and rhodium (Rh) are attractive metals for the FM(s) as they can withstand the harsh conditions of the plasma environment and have better reflectivity. However, the high cost of Rh limits its use as a single material in the FM; as a result, it is deposited as a thin film over a metallic substrate. Moreover, due to the different thermal expansion of the coated materials on FM leads to weak adhesion of the thin layers thereby reducing the life of the coated mirror; this eventually leads to the deterioration of the optical properties of the diagnostic mirror. Furthermore, this phenomenon is becoming a problem concerning the stainability and reflectivity of the diagnostic mirror. This study aims to show the performance of niobium (Nb) as an interlayer between Mo and an Rh thin films deposited via DC magnetron sputtering at the deposition power of 40 W. The Mo mirrors were exposed to the high temperature and were left to cool naturally to room temperature. Rougher surfaces, larger grain sizes, and excellent adhesion were observed. The overall reflectance of the mirrors exposed to high temperature was reduced by 10–15%.

Cheiloscopy – a diagnostic and deterministic mirror for establishment of person identification and gender discrimination: a study participated by Indian medical students to aid legal proceedings and criminal investigations

Cheiloscopy – a diagnostic and deterministic mirror for establishment of person identification and gender discrimination: a study participated by Indian medical students to aid legal proceedings and criminal investigations

Cheiloscopy - A diagnostic and deterministic mirror for establishment of person identification and gender discrimination: A study participated by Indian Medical students to aid legal proceedings and criminal investigations

Introduction: Positive foolproof identification of known or unknown, living or deceased individuals are the primary universal roles in forensic criminal or social investigations wherein the definite procedures such as finger printing, karyotyping, dental records play the director role although expensive and technique sensitive. Herein lies the importance of oral and peri oral tissues in which cheiloscopy is an emerging, cost effective and simple technique. Cheiloscopy (derived from the Greek word cheiloswhich meaning lips) is the study of characteristic patterns of depressions and elevations, anatomically found on oral mucosa. Previous studies have proved that lip prints were unique permanent records of human being analogous to finger prints, hence its classification for a particular individual can be a source of antemortem record in future for a correct identity. Materials and Methods: The study sample comprised of 150 medical students i.e., 88 boys and 62 girls in age group of 18–21 years of Government Medical College, Raigarh, Chhattisgarh. With prior ethical clearance (vide ethical dispatch number 200 dated December 07, 2015) and informed consent, lip prints were recorded by application of a nonsmudged but thin and even coat of dark colored lip stick over the oral labial mucosa of the upper and lower lips and transferring the obtained replica to a cellophane paper fixed on to a permanent bond paper. The lip prints were analyzed with classification of Suzuki and Tsuchihashi for discrimination of gender in addition to individual personal identification and common lip print patterns in Raigarh. Observation and Results: The results showed that of the total 150 students, 133 (88.67%) were correctly identified. The common lip pattern among males in the study was Type III (28.41%). Among females, Type I (33.87%) was the dominant pattern. Males showed grading of lip print pattern as III > IV > II > I’ > I > V and females had a grading pattern was of II > I > I’ > III > IV > V. Conclusion: As lip prints do not change during the life of a person hence still further studies needs to be undertaken to substantiate the cheiloscopic technique on the upper crest as a predominant technique for personal and gender identification. Keywords: Cheiloscopy, gender identity, lip prints, sex determination, Tsuchihashi classification

Major aspects of the design of a first mirror for the ITER core CXRS diagnostics

The ITER core charge exchange recombination spectroscopy diagnostics (cCXRS) occupies the vacuum vessel upper port #3 and includes, in its generic version, the following in-vessel components: an optical mirror system, a shutter, the diagnostic first wall and the neutron shielding block. The most vulnerable diagnostic mirror is obviously the first one (M1) directly observing the plasma. The M1 reference option is made of a single crystalline molybdenum (ScMo).The paper indicates major aspects influencing the first mirror design and identifies the most reasonable and reliable concept for cCXRS M1 at present. The applicability of the option presented is determined by many reasons, and especially, by the ITER generic upper port plug and its customization flexibility.The largest dimension of the mirror polished face is ∼300mm. Such large ScMo workpieces are currently not available on the market. The mirror should be designed as an assembly of several ScMo pieces joined together.The M1 design is supported by multifield thermal, electromagnetic and structural analyses. The performed study confirms the feasibility of the proposed solutions. At the same time, the paper indicates numerous technological issues of the M1 unit to be solved in future.

COMPARISON BETWEEN HI AND ELISA IN DETECTING IMMUNE TITER FOLLOWING IBV VACCINATION

Serological assays can be used for evaluating immune response post vaccination, they can be also helpful in studying the status of maternally derived antibodies (MDA), and they can also give a diagnostic mirror for viral sero-epidemiology. In the present study comparison between hemagglutination inhibition test (HI) and Enzyme linked immunesorbant assay (ELISA) and their abilities to detect IBV antibodies at different circumstances (post vaccination, infection, and (MDA) was studied. HI test for IBV was performed against two distinct IBV serotypes namely (Mass- 41, 4/91). Since they are the major vaccines used commercially in the Egyptian market. ELISA was performed at two dilutions (1/100, 1/ 1000) which is nearly the reciprocal of dilution of (7 and 10) in HI test in a trial to set two points for comparing the obtained results From the two tests. ELISA test showed 100% sensitivity and specificity at dilution 1/100 and showed 80.96%, 95.5 % respectively at 1/1000 dilution. The sensitivity and specificity of HI test were 80.91%, 95% respectively when Mass-41 antigen was used and was 73.91 %, 62 % when 4/91 antigen was used .The difference in sensitivity and specificity with HI reflects it selectivity during serotyping and this picture will necessarily differ if samples were tested against other antigens like (D- 274, 1466,…..etc.,) this confirms our point of view for using HI in detecting immunity after IBV vaccination. It became obvious that ELISA result may be misleading as seen during studying MDA in sample (S-20), ELISA reading at 1/100 dilution was 12051±2018 with STDV(6384) and was 2406±754 with STDV(2385) at dilution 1/1000 their Conversion into two base log titer 1/10 will be 14.28±.317 and 14.56±.4 respectively on the other hand the HI titer was 4.5±.166 with STDV(0.5) when Mass – 41 antigen was used and it was 2.4±.476 with STDV (1.5) when antigen 4/91 was used, result of ELISA will be conflicting when devising a vaccination protocol for such flock.

Ellipsometric and electron spectroscopic study of degradation of optical properties in Mo mirror irradiated with deuterium and/or helium ions

Degradation of optical properties in Mo mirrors irradiated with helium and/or deuterium ions has been studied by ellipsometric spectroscopy, electron energy loss spectroscopy, and electron microscopy. It was found that values of the optical constants (reflectivity, refractive index, and extinction coefficient) of the specimens decreased in the order of deuterium, deuterium and helium dual-beam, and helium irradiations. The penetration depth of the laser light in the specimen, estimated from the observed extinction coefficient, increased in the same order. Electron energy loss spectroscopic study on an individual helium bubble formed in a specimen without surface roughness clearly revealed that the reflectivity decreased owing to a change in the di-electric constants caused by the formation of the bubble, and it was associated with a decrease in the optical constants. These results and the microstructure observation indicate that the degradation of reflectivity originating from the helium bubble is the primary issue affecting a diagnostic mirror irradiated with charge-exchange neutral particles.

Increase of Diagnostic Mirror Lifetime Using TiN Coated Stainless Steel by Using a Plasma Focus Device

Plasma-surface interaction experiments on TiN coated stainless steel 316L (S.S.316L) using a plasma focus (PF) device have been performed in an attempt to investigate whether we can use the hardness property of TiN against erosion to increase the lifetime of the mirrors used in plasma diagnostics equipment. Firstly, two similar S.S.316L samples were chosen for this purpose. One of the samples was coated with TiN by using a PF device, while the other was kept intact as a reference for investigating the effect of TiN coating. Then, in order to study the coating effects, these samples were exposed to 200 shots of hydrogen plasma with a total duration of 7 s in a tokamak. Before and after exposure, samples were analyzed by using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and a spectrophotometer. It was found that the uncoated sample was severely damaged, its reflection dropped significantly, and it developed some cracks and lines, while no significant change was observed on the surface characteristic of the coated sample. Moreover the weight loss of the uncoated sample was higher in comparison to the coated one. Therefore the results of this experiment showed that the coating of S.S.316L by TiN using a PF device is a useful method to strengthen it against plasma erosion and with further optimization it could possibly be used in preparing plasma diagnostics mirrors.

Modeling of the first mirror surface composition under ITER relevant particle irradiation

Abstract Metal mirrors are widely used for optical diagnostics in ITER. Degradation of the mirror surface due to erosion and impurity deposition leads to deterioration of its reflecting properties. In the paper the transport of impurities in a cylindrical steel duct and surface composition change of a diagnostic molybdenum mirror irradiated simultaneously with D, He and Be atoms is simulated for the outer equatorial port of ITER. Net-deposition of Be and Fe on the mirror surface is found even for small Be fraction in the incident flux. The main reason is the formation of a mixed layer due to the high-energy CX-neutrals. However, using the protective duct with the aspect ratio L/D = 10 leads to 14,000 times reduction of Be flux to the mirror compared to Be flux to the first wall; this characteristic factor is sufficiently lower in the cases of L/D = 5 and 2.

Simultaneous imaging/reflectivity measurements to assess diagnostic mirror cleaning

Practical methods to clean ITER's diagnostic mirrors and restore reflectivity will be critical to ITER's plasma operations. We describe a technique to assess the efficacy of mirror cleaning techniques and detect any damage to the mirror surface. The method combines microscopic imaging and reflectivity measurements in the red, green, and blue spectral regions and at selected wavelengths. The method has been applied to laser cleaning of single crystal molybdenum mirrors coated with either carbon or beryllium films 150-420 nm thick. It is suitable for hazardous materials such as beryllium as the mirrors remain sealed in a vacuum chamber.

Fatal Damages due to Breakdown on a Diagnostic Mirror Located outside the Vacuum Vessel in JT-60U

Fatal Damages due to Breakdown on a Diagnostic Mirror Located outside the Vacuum Vessel in JT-60U

Active control over carbon deposition on diagnostic components and in remote areas of ITER

In future fusion devices like ITER deposition of impurities will likely occur in areas, remote from plasma and on the sensitive components of optical diagnostics, like mirrors and windows. Deposition in remote areas may lead to the tritium retention and therefore represent a safety issue. Deposition on optical components will severely deteriorate their optical properties potentially leading to the shutdown of the respective diagnostic systems. An active control over deposition is therefore highly desirable. The paper contains an overview of experiments on active control over carbon deposition undertaken in TEXTOR tokamak. A prototype of diagnostic duct was exposed in the scrape-off layer plasmas of TEXTOR where several techniques were applied to mitigate carbon deposition on diagnostic mirrors located inside this prototype. The complete suppression of carbon deposition on the surface of diagnostic mirror was achieved by feeding the deuterium gas inside the diagnostic duct.

Time resolved deposition measurements in NSTX

Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2μg/cm2 of deposition, however surprisingly, 15.9μg/cm2 of material loss occurred at 7 discharges. The net deposited mass of 13.3μg/cm2 matched the mass of 13.5μg/cm2 measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition.

Deposition diagnostics for next-step devices (invited)

Deposition in next-step devices such as ITER will pose diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons however, diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect dust particles on remote surfaces was commissioned on NSTX.

Experimental and computer investigation of the diagnostic mirror behavior under sputtering and duct material deposition

Experiments on stainless steel duct material, W and Mo mirror surfaces as well as modeling of the experiment using a new computer code which takes into account scanning tunnelling microscope measured surface topography are described. Simulations of the sputtering yield as a function of the primary ion energy and the angle of incidence for ion irradiated targets demonstrated the difference in behavior for ideally smooth, non-irradiated and irradiated targets.

A CLINICAL AND PATHOLOGIC STUDY OF ORAL DISEASE

In presenting this group of cases of oral lesions my primary intention is to give a statistical incidence of diseases and lesions that involve the oral cavity to fill in a hiatus in medical literature. In a compilation of the various groups, some comment is indicated to clarify the various conditions involving specific locations in the mouth and to dilate on some of the specialdiseases and some of the more recent theories accounting for oral disease. The oral cavity has always been a no man's land as far as any group of physicians or dentists can claim a special knowledge of the multitude of lesions found in this domain. As the mouth reflects in many instances disease processes elsewhere in the body, it can well be considered the diagnostic mirror of the body. No group of medical specialists is better fitted by training to lead the way in stimulating