Shielding Definition and 158 Threads

Hello. I've recently have a lot of question of building Faraday cage for our high voltage gas discharge lab. I think this question is a kind of fundamental question for such a job. Let's say I would make perfect Faraday cage with perfect shielding or have metal plate of infinity transverse...

So I'm trying to run some 3D transient simulations based on magnetic field focusing/shielding, but I'm not getting the expected results. Does anyone know if Ansoft Maxwell 14.0 will solve for the magnetic fields created due to the eddy currents? It doesn't appear to.

I've put a small battery powered commercial radio inside a Quality Street tin. The tin is all metal with rolled joints and the lid is a tight fit. I'd be willing to bet that there are no holes greater than 0.1mm around the lid's closure. Why does the radio work when receiving an AM station (1...

My question was was that though you don't have any charge on the inner surface of a metallic cavity but still there's a potential. Can't that potential electrocute someone?

Hello. Let's say there is a instrument needed to be EM wave-shielded in High voltage discharge lab. Building Faraday cage becomes necessary and the instrument is moved to inside the cage. The cage is grounded to lab ground and the frame ground of the instrument (it is also signal ground for the...

thickness of steel plate required to stop interaction between 3' dia neodymium magnet

I have an issue that appears to be relating to noise mitigation and grounding. Some background on myself is I have a mechanical engineering technology degree. But my job requires an ability to work with and troubleshoot electrical issues. Currently a customer is using a Servo motor on an end...

A point charge outside a hollow conducting sphere will produce no field in the hollow interior: the metal shields the interior. But a point charge inside the hollow interior will produce a field outside: the same metal ceases to act as a shield. Why is this? (In particular, aren’t “inside” and...

I have a 3 conductor wire that are all wrapped in a foil shield with wire conductor, for a total of 4 wires. I am connecting the 3 inside wires to audio left, right, and ground. This is an unbalanced setup, right? Where/how do I connect the shielding? Do I connect both sides (i think no)...

Hello, Does anyone shield themselves from computer / monitor from EMF radiation? if so what materials do you use to cover/coat your electronics? I am buying an EMF meter soon (Trifield 100XE) and plan on solving all my EMF issues, specifically around my computer tower, monitor, and other...

I have to make a shielding calculation of some radioactive scrap metal in a cask, using Geant4 (hence Monte-Carlo). I will be given a nuclide vector and I'll have to calculate the ambient dose equivalent rate outside of the cask. The nuclide vector I will be given will be something like: Co60...

Assuming all orbitals are filled, which of these orbitals is most shielded: 1s, 3s, 4d, 5s The answer is 4d, but I chose 5s. Can someone explain? I thought the electrons in the d block are considered core electrons and contribute to the shielding, but feel more pull from the nucleus because of...

Hi, I'm working on a project, interested in your opinion Need a material for magnetic "shielding" There must be no repulsion or attraction between M1 and S since non of them is stationary and it would affect the motion. There will be a ferromagnetic material behind S that cannot be affected...

i want to specifically focus on the mechanism inside an atom . suppose there are some electrons in the nth shell of the atom. They reduce the effective nuclear attraction on the electrons in the (n+1)th shell. can we say that the vector fields of the n shell electrons and the nucleus superimpose...

Suppose a constant electric field exists in space as shown in the file and a open lid cube type conductor is brought inside the field. What would be the electric field in the question marked area. Would it be zero or equal to original electric field.

Hi folks Please bear with me, I'm new here and this may not be the correct forum to ask this question. If this is the case, I'll of course remove my question and ask it the appropriate place instead. However, here it goes: I need to be able to calculate how much a given intensity of gamma...

After Lockheed Martins announcement that they were developing a fusion reactor that might fit on the back of a pickup truck, I got into a conversation with someone about how one would shield such a device. So I found some tables that described the cross section of protons at different energy...

First before asking the original question i need to make sure some of my concepts are correct: 1- what happens when a capacitor with its 2 plates having different areas is charged? according to this forum https://van.physics.illinois.edu/qa/listing.php?id=23409 as the long as the difference in...

Why do electrons present in spherical shaped s-orbital shield the outer electrons from the nucleus more effectively as compared to electrons present in p and subsequent orbitals? Please explain in a layman language I'm just in class 11th. :/

I understand that, for example, a thick enough sheet of lead can absorb gamma radiation, but I want to understand what actually happens at the molecular/atomic/subatomic level. Also, can the same logic be applied to cosmic particles? I have tried Googling for an answer, but to no avail. Can...

Why x-ray shieldings are important part of medical technology?

I heard that many industries use lead for shielding harmful radiation. do you know why?

Shielding -- Need to ground an electrostatic shield? I am reading this app note by analog devices: http://www.analog.com/static/imported-files/application_notes/41727248AN_347.pdf At the bottom of the first page it says: "An electrostatic shield, to be effective..." "But grounding the...

so i understand that if there's a piece of metal between 2 repulsing magnets, the magnets attract to the metal as well, and the repulsion could cancel out the attraction... right? i mean is this even true. if not why not... if it is true, then is it possible to have 2 wheels of repulsing...

I know lead is a great shield against gamma particles due to its extraordinary density, but I wonder if it can also block beta particles, or is it transparent to them due to being electrically conductive? Thanks ahead of time for your responses!

I've been reading about fast reactor designs lately (not necessarily ones that have actually been built). A few articles I've come across < https://drive.google.com/folderview?id=0B-MNeRy61MgpTVExcUQ3T3ZWWG8&usp=sharing > discuss the possibility of building fast reactors, fueled with molten U...

While thinking about the recent-ish developments in meta materials for 'cloaking' systems, a thought struck me: could a meta material or combination of meta materials (probably of a somewhat more advanced state than they currently are) be used as a form of shielding from cosmic rays of various...

as i have understood, in a many electron atom the degeneracy is lost due to shielding effect. and from quantum mechanical model of one electron atom we can say that keeping principal quantum number(n) fixed, the radius at which radial probability function takes maximum value decreases with...

Can someone explain the concept to me? As far as I know, in some energy interval there are materials which have resonance absorption. The book then goes on to say that energy self shielding does something to combat this absorption but I am not clear on how and hope someone can clear this up for me.

Hi, how can we reduce field at a point(of observation) 30mm from a 10 m long blank copper wire with return path somewhere at infinity carrying DC current by using a 1m long copper tube 1mm wall thickness and 30mm outer diameter?

My professor has given me a project, figure out how to magnetically shield some detectors which surround a solenoid. Now, we have mumetal tubs which fit the detectors, but he wants numbers. The solenoid outputs a maximum of 6 Tesla, and it's in a dewer, so there's no way for me to perform actual...

I was thinking whether it was possible to shield a portion of a circuit that has only a single conductor without a return path. The frequency is high enough for the Earth's capacitive impedance to be low. Is my assumption then correct that the induced voltage in the shield will create a...

Greetings to all I had some problems using MCNP5 for gamma shielding calculation. The original input file is from a document by George E. Chabot, Jr., PhD, CHP Shielding of Gamma Radiation. The description of the problems are following: 1) Three different shielding materials, namely...

So I am in the IB, and I have to do an extended essay. I'm doing it in physics, and I'm looking at the topic "What materials offer the best shielding against an electromagnetic pulse (EMP)?" I was thinking of measuring the electromagnetic pulse using an oscilloscope. The reason I want to...

In my chemistry class we just started doing stuff with ionization energy, atomic radius, etc., and I've heard the phrase "electron shielding" tossed around a lot. When I tried to look it up online, most places use "shield" as the verb describing this process, which is not very helpful. The most...

First I am sorry if this question is not quite related to this forum. But I have not where to go So I just post it here hopfully one can help. Thanks in advance. I have two strong magnets. Each has around BrMax: 13200 gauss and pull force 27 lbs. I am looking for a magnetic shield...

Hi, I am doing an university project that consists in building a robot that operates in a AC to DC convertor. The robot has to work under HV environment. I am looking at possibilities of shielding the electronics of this robot. Can you give me any suggestions or links to look at? Also, will...

Ok, is doubt this actually works well. Some guitarists shield their guitars in the cavity of the pickup and the pick guard with conductive foil. This is supposed to work like a faraday cage. The pickup is basically a solenoid that "pick ups" the magnetic field from the magnetized string. So...

Hi all I'm doing a project for energy efficient buildings with thermal insulation.(Just a leisure project and I am not technically that strong!) This is about thermal radiation shielding. My understanding is that Aluminium has higher reflectivity (Hence lower emissivity ) so that it...

Hi everyone, I have two questions related to magnetic fields. Firstly, if I have two bar magnets with opposite poles facing each other, ie NS - NS, how do I measure the magnetic field strength at any point between the two magnets? Secondly, how would I shield the magnetic fields of the...

Hi I'm wondering what properties affect the propagation of electromagnetic signals. I am interested why an aluminium case would adversely affect signal propagation, for example in this case, here And why is it that a small gap in that casing will allow signals to propagate? (is the...

my scenario: so we are working on a problem in a building and are struggling with making the top floor (cable and other assorted digital equipment) playing nice with the bottom floor warehouse (digital ballasts on the ceiling). my question: where does the interference 'come from'? light...

i have to design one shielding box. in that there is cylinder having high voltage +60kev. and box having metal plate. so i have to calculate the electric field on that cylinder and then decide , what should be the distance in between plate and cylinder. i have attach the geometry on the file...

Homework Statement I did a radiation lab a few weeks back. The task was basically to map out radiation intensity as a function of shielding thickness. A Cs137 gamma ray source was used, and lead was used as the shielding material. Data was taken meticulously and over long periods of time so as...

Hi all, It doesn't seem that a relativistic ship traveling in deep space would need much shielding due to particles at rest in the space frame, appearing relativisitc now in the ship's frame. Here's the calculation I did: Let's imagine a ship the size of a space shuttle traveling with γ of...

hello. I need to use a "coaxial" câble with 6 kV on axial wire. May I use a TV coaxial wire ? Will it be able to support such voltage. Anyway I must transport this HV and it must be shielded. A suggestion ?

Let's say a shielded cable is in the vicinity of noisy environment with plenty of EMI. How to go about cancelling the common mode currents, so that the magnetic field gets cancelled. It's pretty simple in case of differential mode currents. The mag field from the forward current and return...

I just read a short story about a post apocalyptic world in which humanity was on the brink of destruction due to the loss of protection from the planetary magnetic field (pole reversal in progress, process turns out to take some 100 years to finish). Electronics go haywire and large amounts of...

Hi, I have two questions that come from a unique example of magnetism. Here is the scenario: a thin and long piece of iron is placed in between a magnet and the north pole faces the outing sheet and some iron tacks. The iron tack do not get attracted to the iron even though a south pole is...

Hello , If I wanted to design a radiation shield to protect from line source of Ca-252 with 5.3 Ci what is the first thing I should think about..?