In combination with a remote keyboard, simply create narrow 5 sided shielding box which is open at the back using Magnetic Shielding Foil. Hard X-rays can penetrate solid objects, and their largest use is to take images of the inside of objects in diagnostic radiography and crystallography.
The roentgen (R) is an obsolete traditional unit of exposure, which represented the amount of radiation required to create one electrostatic unit of charge of each polarity in one cubic centimeter of dry air. The rad is the (obsolete) corresponding traditional unit, equal to 10 millijoules of energy deposited per kilogram.
The sievert (Sv) is the SI unit of equivalent dose, which for X-rays is numerically equal to the gray (Gy).
X-rays are generated by an X-ray tube, a vacuum tube that uses a high voltage to accelerate the electrons released by a hot cathode to a high velocity. In crystallography, a copper target is most common, with cobalt often being used when fluorescence from iron content in the sample might otherwise present a problem.
X-ray fluorescence: If the electron has enough energy it can knock an orbital electron out of the inner electron shell of a metal atom, and as a result electrons from higher energy levels then fill up the vacancy and X-ray photons are emitted. So the resulting output of a tube consists of a continuous bremsstrahlung spectrum falling off to zero at the tube voltage, plus several spikes at the characteristic lines. In medical diagnostic applications, the low energy (soft) X-rays are unwanted, since they are totally absorbed by the body, increasing the dose. To generate an image of the cardiovascular system, including the arteries and veins (angiography) an initial image is taken of the anatomical region of interest. A specialized source of X-rays which is becoming widely used in research is synchrotron radiation, which is generated by particle accelerators. The most commonly known methods are photographic plates, photographic film in cassettes, and rare earth screens. Before the advent of the digital computer and before invention of digital imaging, photographic plates were used to produce most radiographic images.
Since photographic plates are sensitive to X-rays, they provide a means of recording the image, but they also required much X-ray exposure (to the patient), hence intensifying screens were devised. Areas where the X-rays strike darken when developed, causing bones to appear lighter than the surrounding soft tissue. Contrast compounds containing barium or iodine, which are radiopaque, can be ingested in the gastrointestinal tract (barium) or injected in the artery or veins to highlight these vessels.
An increasingly common method is the use of photostimulated luminescence (PSL), pioneered by Fuji in the 1980s.
The PSP plate can be reused, and existing X-ray equipment requires no modification to use them. For many applications, counters are not sealed but are constantly fed with purified gas, thus reducing problems of contamination or gas aging. Some materials such as sodium iodide (NaI) can "convert" an X-ray photon to a visible photon; an electronic detector can be built by adding a photomultiplier. HONGER TECHNOLOGY is a high-tech company specializing in the development and distribution of Permalloy cores, Amorphous microlite cores, Nanocrystalline cores and various kinds of Permalloy shielding parts, as well as other related magnetic products. Our products are widely used in miniaturization and energy saving devices, in electronics and for power supply. The aim of this paper is to obtain shielding efficiency of such device and to show that such shielding device can be very accurately modeled by using surface integral-equation formulation (SIE) Method of Moments (MoM), built in WIPL-D Pro.
Conductive spherical shell illuminated by a plane wave was modelled and simulated in WIPL-D Pro (Figure 1).
In WIPL-D Pro, we added a fictitious dielectric filling the cavity (with dielectric properties the same as air). For the sake of better modeling of the EM field inside the spherical cavity, one more surface between outer and inner shell surface has been added (Fig. By adding this middle surface, number of unknowns is increased for 50% comparing to original model. Ratios between magnitude of incident electric field and magnitude of electric field in the center of cavity, with conductivity and skin depth are presented in Table 1. Results obtained by using MoM SIE implemented in WIPL-D software and applying theorem of surface equivalence show high accuracy even in case when skin depth is significantly less than thickness of conductive walls. Almost perfect matching between analytical solution and solution obtained by simulating the model in WIPL-D Pro software occurred, although field level inside the cavity was more than 150 dB below the field level of incident wave (Fig. If you have a specific problem in mind and you are not sure if WIPL-D software can handle that problem, contact us.
Let us calculate the shielding effectiveness of a PEC box with a slot, excited with a plane wave incident in the direction perpendicular to the slot.

A rectangular metal enclosure with an aperture on one face can be modeled as a waveguide, shorted at the far end, with the aperture at the entrance to the waveguide. The electric field shielding effectiveness is calculated as the ratio of the impinging field to the field measured at some point within the waveguide, distant from the slot. The theory assumes that a single TE10 waveguide mode propagates from the aperture and normal to it. The objective is to investigate the influence of changes in box and slot geometry as well as in position inside the box at which field is calculated on shielding effectiveness (Fig. For fixed dimensions of the box and of the aperture (a=30 cm, b=12 cm, d=30 cm, l=10 cm, w=0.5 cm), shielding effectiveness at various positions within the box (at the symmetry plane) is displayed in Figs 3 and 4. If we fix everything except the width of the box (a), then for b=12 cm, d=30 cm, l=10 cm, w=0.5 cm and p=15 cm, and by varying a from 20 cm to 40 cm, we get Figs 5 and 6. By fixing all parameters except the length of the slot to a=30 cm, b=12 cm, d=30 cm, w=0.5 cm and p=15 cm and varying l from 3 cm to 17 cm, we get Figs 7 and 8. A closer look at the fields inside the box at several frequencies within the range from 700 MHz to 1.3 GHz was done in order to illustrate higher order modes that form.
As operating frequencies increase and devices become more complex, they may be more susceptible to electromagnetic interference (EMI). We are a global market leader in the production of EMI shielding materials and Faraday cages. Worldwide leading manufacturer of EMC (electromagnetic compatibility), EMI (electromagnetic interference) and RFI(radiofrequency interference) shielding solutions.
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Since most of the magnetic field from a laptop comes from the base, there is no need to shield the screen.
If your laptop tends to heat up, be sure to make the shield large enough to allow adequate ventilation.
This process produces an emission spectrum of X-ray frequencies, sometimes referred to as the spectral lines.
The intensity of the X-rays increases linearly with decreasing frequency, from zero at the energy of the incident electrons, the voltage on the X-ray tube.
A second image is then taken of the same region after iodinated contrast material has been injected into the blood vessels within this area. The contrast compounds have high atomic numbered elements in them that (like bone) essentially block the X-rays and hence the once hollow organ or vessel can be more readily seen. In modern hospitals a photostimulable phosphor plate (PSP plate) is used in place of the photographic plate. The exact purpose of EM shielding is to protect devices from the undesirable coupling between interior and exterior space of the device. Importance is especially expressed if electrical device we try to protect is very sensitive on interferential fields. In order to minimize interference field inside the shell, shell thickness is usually few times larger than skin depth. Modeling and simulating of this shell is obtained in WIPL-D Pro software and these results are compared with Mie series analytical results.
Nevertheless, with the additional surface, very good field approximation in the shell and accurate results for the field inside cavity are obtained. Electric field inside cavity for skin depth equal to eighths of shell thickness.3 surfaces were used.
5, we see that it is possible to obtain acceptable results if higher level of integration is used, even in the case when skin depth is equal to just eighths of shell thickness. We will analyze your needs and try to help, and if our products satisfy your requirements, we will make you the best possible offer for purchase. Higher order modes, and modes propagating in other directions may exist which will complicate the results, and introduce need for EM simulation in order to predict the shielding effectiveness. The shielding effectiveness is worst close to the slot while it increases as we move away from the slot.
Shielding effectiveness is directly related to the size of the slot, and it decreases as the slot grows. In many examples, this can be further diminished using symmetry planes to about 200 unknowns. The personal and effective approach we bring to every job we work on, makes the difference.

The spectral lines generated depend on the target (anode) element used and thus are called characteristic lines. These two images are then digitally subtracted, leaving an image of only the iodinated contrast outlining the blood vessels.
Photographic film largely replaced these plates, and it was used in X-ray laboratories to produce medical images.
In the pursuit of a non-toxic contrast material, many types of high atomic number elements were evaluated.
After the plate is X-rayed, excited electrons in the phosphor material remain "trapped" in "colour centres" in the crystal lattice until stimulated by a laser beam passed over the plate surface. Electrons accelerate toward the anode, in the process causing further ionization along their trajectory. Permalloy can divert magnetic flux and effectively protect sensitive components from near by magnetic source.
This means, that field on outer surface of the shell is much larger than field on inner surface of the shell.
Because of so large difference in field levels, propagation of numerical error through the walls of the shell appears.
By setting calculation of near field just in this added domain, we actually set calculation of near field by using theorem of surface equivalence. The subsidiary depth-wise resonance shifts up in frequency as the probe moves towards the back. 9 shows near fields at different frequencies in case when the incident plane forms an angle of 75 degrees with the normal to the slot. Simulation in 100 frequency points takes about 40 seconds on a Intel Core2 Duo CPU with 2.66 GHz clock. EMI shields are commonly implemented in a design to isolate one component or section of a device from another. Our strategy is to go all the way on each project to achieve the highest possible shielding results and to satisfy our customers.
The radiologist or surgeon then compares the image obtained to normal anatomical images to determine if there is any damage or blockage of the vessel. In more recent years, computerized and digital radiography has been replacing photographic film in medical and dental applications, though film technology remains in widespread use in industrial radiography processes (e.g.
For example, the first time the forefathers used contrast it was chalk, and was used on a cadaver's vessels. This process, known as a Townsend avalanche, is detected as a sudden current, called a "count" or "event". To this end, we have always recognized and valued our customers and their needs and have made a long-term commitment to provide high quality products as well as a professional service. HONGER TECHNOLOGY deeply believes that best quality products, a fast and efficacious supply system, and thorough customer service are the way to win trust and loyalty from our customers. According to this, if we want to obtain accurate results, large field variation over short distance should be properly analyzed. The results of EM simulation are in excellent agreement with results obtained by using intermediate level simulation tools from University of York, and easily obtainable by using their online calculator [1] . To ensure a reliable and robust electrical seal, an EMI shielding gasket is often incorporated between the shield housing and the mating surface of the device. When the film is developed, the parts of the image corresponding to higher X-ray exposure are dark, leaving a white shadow of bones on the film. Photographic plates are mostly things of history, and their replacement, the "intensifying screen", is also fading into history. Electric field (RF) can be effectively shielded by conductive material properly grounded, but the magnetic field is not easily shield and requires highly permeable material such as Permalloy or Mu-metal. The metal silver (formerly necessary to the radiographic & photographic industries) is a non-renewable resource. Thus it is beneficial that this is now being replaced by digital (DR) and computed (CR) technology. Where photographic films required wet processing facilities, these new technologies do not.

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