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Tomographic capabilities of the new GEM based SXR diagnostic of WEST
摘要： The tokamak WEST (Tungsten Environment in Steady-State Tokamak) will start operating by the end of 2016 as a test bed for the ITER divertor components in long pulse operation. In this context, radiative cooling of heavy impurities like tungsten (W) in the Soft X-ray (SXR) range [0.1 keV; 20 keV] is a critical issue for the plasma core performances. Thus reliable tools are required to monitor the local impurity density and avoid W accumulation. The WEST SXR diagnostic will be equipped with two new GEM (Gas Electron Multiplier) based poloidal cameras allowing to perform 2D tomographic reconstructions in tunable energy bands. In this paper tomographic capabilities of the Minimum Fisher Information (MFI) algorithm developed for Tore Supra and upgraded for WEST are investigated, in particular through a set of emissivity phantoms and the standard WEST scenario including reconstruction errors, in?uence of noise as well as computational time.
关键词： Plasma diagnostics - interferometry, spectroscopy and imaging,X-ray detectors,Micropattern gaseous detectors (MSGC, GEM, THGEM, RETHGEM, MHSP, MICROPIC, MICROMEGAS, InGrid, etc),Radiation calculations
更新于2025-09-09 09:28:46
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Detection and Treatment Systems based on Optics and Photonics in New Age Healthcare Management
摘要： The world is becoming smaller in the means of communication and information but we are yet short to make basic medical needs deliverable universally. There have been many breakthroughs and advancements in the field of medical and healthcare but they fall scant in stature, in terms of taking care of major healthcare problems across the globe. If we look closely, major healthcare problems can be classified as primary and secondary. Accurate diagnosis, treatment and therapies for severe diseases and disorders which are prolonged threat to life form the primary healthcare problems. Secondary health care problems include conditions like trauma, or accidents, or mishaps in daily life. The latter healthcare conditions demand for quick and immediate medical attention for stabilizing the victims and then initiate recovery. Human population is advancing in terms of medical technologies with respect to diagnostic and treatment modalities to tackle serious healthcare issues, but most of the latest medical technologies are available in established centres which are formed by a high economic investment. The high cost makes the technology unavailable to a majority of the population residing in developing countries. In cases of road trauma several factors need to be considered within a small time frame to provide immediate medical supervision, also medical procedures to be provided simultaneously in no time. The loss in time in such cases eventually leads to loss of life or loss of functionality of organs. Excessive losses of blood or internal injuries are most common but are involved with most time consumption for proper attention and diagnosis leading to irreversible lethality to important organs like brain, heart, liver or kidneys. Thus researchers are continuously developing diagnostic and therapeutic systems which are affordable in resource poor settings. Optical technologies provide most suitable approach for deployment in resource poor settings. Optical technologies are continuously evolving and advancing our healthcare systems. Proper utilization and conditioning of light spectrum and exploring optical properties of novel materials have shown promising results for development of medical techniques. Modification, assembly and combination of optical equipment’s can be easily integrated to form dedicated instruments for health anomalies. As a requirement to increase deliverability, solutions need to rely on new components which travel and transfer information faster. Use of light for above purpose can solve all the above mentioned perils and also provide non-invasive and harmless method of diagnosis and treatment. Diagnostic and scanning techniques like PET, X-ray, CT etc. have already employed optical techniques for in vivo imaging and surgery. Endoscopic examination of GIT involves use of light and camera inserted using a flexible tube and a colour TV monitor is the basic example of use of optics for imaging and visualization of disease manifestations [1]. On the other hand, lasers are part of helpful optical instruments in the medical sector from deep vein thrombosis (DVT) to sutures and vessels sealing from time to time [2,3] In case of DVT by ‘Laser Thrombolysis’ (Use of laser pulses to remove the clots) using different sets of lasers and intensity, timings are used to disintegrate the clot without making unnecessary incisions [2-4]. Lasers are also deployed in sensitive surgical procedures for vision impairment owing to its precision, reach, and less invasive properties. Apart from proven aesthetic uses like tattoo and pigmentation removal, optical instruments are also to be utilized in the field of non-invasive patient monitoring systems as optical pulse and oxygen saturation analyser for uninterrupted patient recovery and observation. Various skin diseases are being tested by scope of optical scanning including skin cancer, chronic pain using ‘photo-dynamic therapy’ [2,3]. The scope of optical techniques in diagnostic and therapeutic usage has been described in the adjoining (Figure 1). The use of optics is not restricted to one property or one field but it appears as vast as its extension in spectrum thus the same source and property of light can also be used in other objectives with few changes, establishing its integration compactly and low energy tool developments. These prospects are greatest and most desirable cues for using optical technology in almost every field where portability and ambulatory utilization is very high in demand. Recently, a healthcare company ‘THERANOS’ developed 140 types of testing and analysis with a single drop of blood and has been well received in scientific community [5]. The product signifies the precision, reaching ability, less invasive nature and adaptability to different needs of the system. Similarly, optical characteristic profiling gives strong hope for testing other soft or hard tissue like bone and density and bodily samples as well on the basis of signal processing internally or by sampling them out in very fewer quantities than the existing procedures. In another application of pulse oximetry red and infra-red light is utilized to get the absorbance of dissolved gasses and saturation level of biological carriers like haemoglobin. Continuous monitoring systems like pulse oximetry capable to detect pulse rates, O2 and CO2 gasses saturation level can be deployed [1-2,6-12]. Infrared thermometers or pulse laser thermometers or temperature guns working on the principle of capturing and measuring infrared emittance of a heated body by focusing it to a particular spot; which is not only applicable in medical field but serves very vast field of applications and industrial areas. Lasers and optics make another robust base for telemedicine and remote analysis prospective in healthcare field with appropriate placements and counter check with other indicative and suggestive parameters. Telemedicine and remote analysis can provide a huge possibility for screening by non-invasive method and remote execution. Development of analytic tools in movement and body structure related disorders with added benefit of being non-invasive as in GAIT and posture analysis [2-7]. Different types of lasers are being combined for the therapies like CO2 lasers are used to make incisions in tissues with low vascularity (mostly used in neurosurgery for precision), while on the other hand with Nd-YAG (neodymium-doped yttrium aluminium garnet; Nd:Y3Al5O12) lasers are applicable in high vascular areas and tumour shrinkage, or surgical removal without leaving scars owing to energy dependent concentration where tumours can be thermally destroyed by concentrating the laser beam. This strategy also prevents undue toxicity to normal cells in comparison to other chemotherapeutic methods [2]. It also allows separation of tumours from vital structures minimizing low risk to surrounding tissues in the removal of tumours with surgeries. Use of monochromatic light absorption property different levels of tissues within internal layers can be operated with success [3,4]. Another example is maintenance of secretory activity of small glands glands can be maintained by using a catheter to remove over-secretory regions by flashing laser pulses. Above mentioned properties surely give an upper hand to practitioners and surgeons for performing highly complex procedures in critical areas like brain where collateral damage can lead to severe implications. Needless to mention that these procedures save a lot of time, effort, risk of collateral damage to surrounding tissues, and manage blood loss in comparison to normal surgical procedure subsequently leading to early and sound recovery without any scar formation or associated complications. Conditions associated with brain are most susceptible and irreversible to collateral damage owing to non-repairable nature of brain structures. Cerebral hypoxia associated with trauma cases due to low blood pressure or clot formation and subsequent fall in essential nutrition is one such process which is not completely understood by researchers and physicians. The neurons are dependent for supplies on the blood flow to the brain and other parts of nervous system, and these constant supplies are utilized in the energy production to carry out different duties, most primarily conduction of impulses via interneuron junctions called synapse in a vast interconnected complex network lying all across the brain tissue. Whenever brain is exposed to resource scanty conditions the important physiological responses are hampered as brain doesn’t have any kind of storage facility for energy produced. The brain does not have pain receptors or physical warning signs for indicating ongoing damage which ultimately leads to brain tissue death [1,2-15]. Cerebral hypoxia causes a partial/complete loss of functionality of brain tissues due to degeneration [12-18]. The most alarming part is that the function of that part cannot be restored by any present therapeutic manner as brain tissue doesn’t inhabit the power of regeneration, surgical and chemotherapeutic treatments are also less effective due to complexity of the organ and the presence of blood brain barrier. Invasive procedures for brain trauma treatment are associated with vulnerabilities to damage of other parts of brain. In response to detrimental conditions, at times the brain activates and alters different control mechanisms of normal physiological factors and bodily conditions under its command; towards the values, which are of opposite effect on present danger in order to nullify its further negative effect on neural tissue. The Brain raises cerebral blood pressure and breathing rates by neural control centre to fulfil elevated demand of oxygen or nutrient. Along with these parameters neural activity at brain also increases several folds to prepare and release more counter measures for present dangerous situation, as biochemical messengers responsible to initiate vascularisation and elevate blood pressure at cellular level by constricting blood vessels, are released in bloodstream returning from cerebral region to increase blood vessels [11,14,15-17]. We believe that research in mapping of cerebral hypoxia can be a new prospective area of research to be dealt using optical methodologies. It is also interesting to see the enthusiasm of national and international organizations who are supporting this initiative by financial and resources aid. It will be astonishing if in near future we can develop a whole automated setup based on optical and electrical components capable to capture whole body scans at once without any human intervention especially in remote and resource poor healthcare settings [3,5,19].
关键词： Optical technologies,Diagnostics,Healthcare,Telemedicine,Remote analysis,Therapeutics,Photonics,Lasers,Non-invasive methods,Optics
更新于2025-09-09 09:28:46
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Multi-diagnostic setup to investigate the two-close-frequency phenomena
摘要： While the mechanism is still not fully clear, the beneficial effect (higher intensity of highly charged ions, stable plasma conditions) of the second microwave injected to the ECR plasma was observed in many laboratories, both with close and far frequencies. Due to the complexity of the phenomena (e.g. interaction of resonant zones, damped instabilities) complex diagnostic methods are demanded to understand its mechanism better and to fully exploit the potential hidden in it. It is a challenging task since complex diagnostics methods require the arsenal of diagnostic tools to be installed to a relatively small size plasma chamber. Effect of the injected second 13.6–14.6 GHz microwave to the 14.25 GHz basic plasma has been investigated by means of soft and (time-resolved) hard X-ray spectroscopy, by X-ray imaging and space-resolved spectroscopy and by probing the rf signals emitted by the plasma. Concerning the characterization of the X radiation, in order to separate the source and position of different X-ray photons special metallic materials for the main parts of the plasma chamber were chosen. A detailed description and explanation of the full experimental setup and the applied non-invasive diagnostics tools and its roles are presented in this paper.
关键词： Ion sources (positive ions, negative ions, electron cyclotron resonance (ECR), electron beam (EBIS)),X-ray detectors,Plasma diagnostics - interferometry, spectroscopy and imaging,Plasma generation (laser-produced, RF, x ray-produced)
更新于2025-09-09 09:28:46
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On evaluating x-ray imaging crystals with synchrotron radiation
摘要： Bent crystals used in diagnostics of plasmas combine x-rays diffracted from across the crystal. Therefore imperfections in the resulting 1-D spectrum or 2-D image are not the best way to find out why one particular crystal may differ in its performance from another and what, if anything, to do about it. Instead, here we want to measure the diffraction locally, with the necessary resolution. Nominally monochromatic and unidirectional radiation from the synchrotron’s standard x-ray optics proved to be insufficient for the purpose. Here much better radiation comes from the x-ray topography setup at the x-ray optics testing beamline 1-BM at the Advanced Photon Source, thanks to a specially designed quartz conditioning crystal. Some worrisome features in a bent crystal’s diffraction have thereby disappeared, while minor fabrication flaws remain highly visible.
关键词： x-ray imaging,diffraction,synchrotron radiation,plasma diagnostics,bent crystals
更新于2025-09-09 09:28:46
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Portable Radiography: A Reality and Necessity for ISS and Explorer-Class Missions
摘要： On ISS missions and explorer class missions, unexpected medical and surgical emergencies could be disastrous. Lack of ability to rapidly assess and make critical decisions affects mission capability. Current imaging modalities on ISS consist only of ultrasound. There are many acute diagnoses which ultrasound alone cannot diagnose. Portable X-Ray imaging (radiography) technology has advanced far enough to where it is now small enough, cheap enough, and accurate enough to give diagnostic quality images sent wirelessly to the onboard computer and on Earth for interpretation while fitting in something the size of a briefcase. Although further research is warranted, Portable Radiography is an important addition to have on ISS and future Explorer Class Missions while maintaining a very small footprint.
关键词： imaging,space diagnostics,radiology,space medicine
更新于2025-09-09 09:28:46
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Fluorescence-Based Real Time Monitoring and Diagnostics of Recombinant <i>Pichia pastoris</i> Cultivations in a Bioreactor
摘要： This study describes the application of the multivariate curve resolution (MCR) analysis technique for real-time analysis of culture fluorescence during recombinant Pichia pastoris cultivation in a bioreactor. Fluorescence spectra were acquired with an on-line dual excitation wavelength fluorometer and then used to develop a real time MCR-based bioprocess monitoring and diagnostics tool. Initial bioreactor experiments using two similar recombinant antibody secreting P. pastoris cell lines showed significant differences in protein production. To distinguish between the contributions of operating conditions and the specific cell line‘s genetic composition to the observed differences in protein production, the bioreactor experiments were repeated and accompanied by real time MCR analysis. The tests demonstrated high sensitivity of MCR-derived ―pure concentration‖ profiles to growth as well as to initial conditions, thus enabling real-time cultivation process trend diagnostics and fault detection.
关键词： fluorescence,monitoring,Multivariate curve resolution,on-line diagnostics,bioreactor
更新于2025-09-09 09:28:46
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SkImager: a concept device for <i>in-vivo</i> skin assessment by multimodal imaging
摘要： A compact prototype device for diagnostic imaging of skin has been developed and tested. Polarized LED light at several spectral regions is used for illumination, and round skin spot of diameter 34 mm or 11 mm is imaged by a CMOS sensor via cross-oriented polarizing filter. Four consecutive imaging series are performed: (1) RGB image at white LED illumination for revealing subcutaneous structures; (2) four spectral images at narrowband LED illumination (450, 540, 660, and 940 nm) for mapping of the main skin chromophores and diagnostic indices; (3) video-imaging under green LED illumination for mapping of skin blood perfusion; (4) autofluorescence video-imaging under UV (365 nm) LED irradiation for mapping of the skin fluorophores. Design details of the device and its software as well as preliminary results of clinical tests are presented.
关键词： optical skin diagnostics,multimodal imaging,skin chromophore and fluorophore mapping
更新于2025-09-09 09:28:46
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Measuring Complex for the Diagnostics of the Quality of Light–Emitting Heterostructures According to Photoelectric and Optical Responses Under Local Photoexcitation
摘要： We propose an automated measuring complex for the diagnostics of the lateral homogeneity of semiconductor heterostructures by measurements and analysis of the photoelectric and optic responses to their local photoexcitation in static and dynamic modes. The electronic-mechanical and optical positioning systems guarantee the illumination of local region of the investigated structure with a minimum diameter of the spot of 14 μm and a positioning accuracy of 10 μm. It is shown that the measuring complex can be used for the diagnostics of the quality of light-emitting heterostructures, transistors, solar cells, and photodiodes.
关键词： local photoexcitation,light-emitting heterostructures,photoelectric response,quality diagnostics,lateral heterogeneity,automated installation
更新于2025-09-09 09:28:46
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The Sun as a Guide to Stellar Physics || Models of Solar and Stellar Atmospheres
摘要： Our understanding of the Sun, other stars, and celestial objects in general is almost entirely based on observations and analysis of electromagnetic radiation in a broad wavelength range, from g-rays up to the radio. This radiation travels to us through the vast cosmic space, more than 8 min from the Sun and billions of years from distant universes. What we detect by our instruments is the result of a complex interaction between the photons and matter inside the objects under study, but also other interactions along the long path to us. To understand these interactions, we have to solve a coupled, generally nonlinear problem of how radiation is transported through such media and how the media, mostly various kinds of plasmas, are affected by penetrating radiation. In this way, we can model the spectrum emergent from various objects; this gives us a deep insight into the structure and dynamics of, e.g., solar and stellar atmospheres. We call this the spectral diagnostics. However, the actual state of an atmosphere may strongly depend on the spectral distribution of the internal radiation field via complex atomic processes, leading, for example, to heating or cooling of the plasma by radiation, along with other processes such as the heat conduction, wave dissipation, or magnetic heating. The whole complexity of these interactions is governed by a coupled system of (magneto)-hydrodynamical equations and equations describing the transport of radiation. This is called radiation hydrodynamics (RHD) and we will briefly describe it at the end of this chapter. On the other hand, considering only the radiative transfer in a prescribed model atmosphere, we deal with a “classical” astrophysical problem that was thoroughly studied during the past century, and to a great extent, the basic concepts were developed by solar physicists. This is usually called the theory of radiative transfer, which was regarded as a synonym of solar or stellar atmospheric physics (e.g., Physik der Sternatmospha¨ren by Unso¨ld, 1938). Among the atmospheres of various stars, the solar atmosphere has the unique privilege of providing us with insight into different structural patterns and their dynamical behavior. This then serves as a guide for our understanding of various phenomena on other stars, namely late-type cool stars. One of the most prominent stellar astrophysicists, D. Mihalas, who was engaged in both solar and stellar atmospheric research, once said, “My views have been colored by my long period of residence at the High Altitude Observatory in Boulder, where I was confronted daily by the ghastly reality of the Sun as seen at high time, spatial, and spectral resolution in a wide range of spectral bands. There is probably no more sobering an experience for a stellar atmospheres modeller than a detailed inspection of solar data!” (Mihalas, 1991). The theory of stellar atmospheres is summarized in an excellent textbook by Hubeny and Mihalas (2015).
关键词： non-LTE modeling,radiation hydrodynamics,spectral diagnostics,solar and stellar atmospheres,radiative transfer
更新于2025-09-09 09:28:46
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Intrinsic resolution limits of monolithic organic scintillators for use in rep-rated proton imaging
摘要： Rep-rated diagnostics are a necessity for present and future laser facilities focused on the study of high-energy-density (HED) phenomena. Electromagnetic fields in HED systems are of particular interest to the community, but are inherently difficult to diagnose due to the high mass-densities involved. By utilizing high-energy protons that penetrate through dense plasmas, fields may be visualized by detecting variations in proton fluence caused by the Lorenz interaction of the protons with the field. Typical detecting media used for proton imaging are single-use and do not scale well to rep-rated operation. We propose here the use of a scintillator-based detector and characterize the energy and spatial responses to demonstrate its feasibility as a viable option for rep-rated proton imaging and other diagnostics.
关键词： Proton imaging,Diagnostics,Scintillator
更新于2025-09-09 09:28:46