Shielding Definition and 158 Threads

So hypothetically you bring a container into an MRI room. Inside the container is a USB drive, a crypto hardware token, an electronic tablet, and a Walkman. Then you run the room's MRI machine, which has a magnetic field strength of 3 Teslas. What kind of container could prevent any...

Hello everyone, I have a question regarding shielding effectiveness and how it relates to SNR. Do you know what equation should be used to calculate SNR based on shielding effectiveness? Let's say the shield is an aluminum foil made into a dome covering transmitter and receiver inside. A general...

TL;DR Summary: Why is HgCl2 more covalent than CaCl2 via shielding? Hg^2+ in HgCl_2 has more shells of p-orbitals and s-orbitals than Ca^2+ in CaCl2 - Do those extra p and s shells of Hg^2 in HgCl2 shield the two chlorines in HgCl2 from the effect of Hg^2+'s nucleus attraction, or leave the...

If Shielding is required for gamma ray flux of 1e23 (let say E=1 Mev). As Shielding cannot fully attenuate flux to zero, how much percentage is technically recommended for shielding of above flux?. So far as I know shield thickness is considered to minimise dose/flux Upto 1/10 of its...

Dear Experts, When a thin conducting sheet with no charge on is placed at a certain distance from a point charge, does it shield the electric field caused due to the point charge from reaching the other side of the sheet. As an extension of that idea, when a conducting sheet or slab is placed...

This is a topic that will be relevant for anyone who plans to use "realistic" artificial gravity (of the centrifugal kind, rather than the "acceleration-based" kind) in their stories - be it on spaceships or space stations: How much of the ring walls has to be dedicated to radiation shielding...

I've been thinking about electromagnetic shielding lately. Of course, you have your good, old-fashioned Faraday cage. But after staring at Maxwell's equations awhile, I'm thinking: We're after a static E field, right? So if we set ## \frac{\partial \textbf{E}}{\partial t}=0## in Ampere's...

Whats shielding effect and effective nuclear charge?

Would using an insulator like rubber tires partly buried in the ground + partly protruding above the land surface to create a continuous perimeter around a piece of land possibly shield the land inside of it from the accumulation of charge on the surface of the Earth which occurs in the vicinity...

I was wondering how they measured or calculated these differences? I don't know what they refer to, but assume theyre scattering Hydrogen with Tritium or Deuterium to measure the difference of something. https://physics.nist.gov/cgi-bin/cuu/Results?search_for=shielding+difference

In this photo you see on the right-hand side that the outer wall current is negative and the inner wall current is positive. That is, they are directed in different directions. But if the applied magnetic field is in the z direction as shown, then shouldn't they both be in the same direction do...

Hi. I was reading about conductors in electrostatic equilibrium and how it makes sense that they have zero electric field inside the material even when an external charge is brought near. The charge density of the material just rearranges itself to cancel. Then I searched for hollow conductors...

What is the classical explanation for why the microwaves won't pass through the microwave door?

Let's assume that I have have one conductor carrying current to the load in one direction and the return line with current in the opposite direction from the load. If the current has high di/dt due to switching, may have EMI issues with nearby circuits. I know that I can put a "ground" plane on...

I may have blown a hole in my plot I can't sew back up. I need a way to shield RF emissions to keep them from escaping into the wilderness. It has to be impractical enough that it can only be implemented on a large scale such as a settlement, not on, say, a vessel.Core premises of the story: -...

So I've been trying to figure out how EMF shielding works. More specifically, I've seen videos where placing a metal conductor in front of a circular coil (with AC running through at radio frequencies) apparently shielded anything behind it. After searching online, I repeatedly saw Eddy...

It seems I don't understand how magnetic shielding supposed to work. I tried shielding a wire, using some ferrites, but it doesn't work. I assumed the magnetic field will concentrate in the magnetic material, bypassing the meter magnetic loop, so less will be measured by the meter. I thought the...

I am watching this video; at the 8:20 mark it shows that a proton in a magnetic field will align with the magnetic field very easily if there is no shielding from electrons, and therefore will require energy to shift to the opposite spin state; makes sense to me. I also understand that when...

Hi, I am looking for the best way to either shield or redirect radiation, particularly Gamma radiation away from vehicles in space with the minimal amount mass. The last thing we need is a few feet of lead. I am hoping to find other options. I would love to redirect radiation away from a...

So I'm trying to put together a Pi Zero mini computer to use for security-oriented applications, for example encrypting/decrypting messages, working with encryption keys, etc. It's cheap, very small and thus easy to carry around. However, I'm not entirely comfortable with the presence of the...

What is true is that the field due to the point charge outside of the conductor will not be able to penetrate the shell i.e. there will be no field due to the external point charge anywhere within the conductor nor in the cavity: the field will be **killed off*& by the charges on the outer...

Concrete for example - you need less concrete to obtain the same lead equivalent for photon energy 500 keV than for 200 keV. What is the reason for this?

So, I have no education in this field. I've really been into mutant breeding and crisper plasmid based genetic engineering. I've read that heavy ions create a greater number of mutagens than electron magnetic radiation such as deep uvc. lately particle accelerators have been on my mind. I'm...

Assume such a situation, if I have a wire and some part of that wire passes through a hole in the core of an inductor or transformer or any other high magnetic field environment , are there ways to shield the wire, the part that intersects with the B field in order to prevent the field from...

I have a bunch of questions on pattern shield for inductors in Integrated Circuits (ICs). Basically, shields are made using thick metals (less resistance) to reduce the coupling to the substrate (which are more lossy generally) in order to improve the Q factor. They are patterned to avoid eddy...

Hello, I've been splicing a HDMI cable which has 19 wires in total I've soldered all the data cables apart from the 5 shielding wires. I'm a little confused because as far as I know the wire shielding is meant to act as a faraday cadge to stop interference. But when I don't connect the shielding...

I am certainly not qualified to really comment on this subject, but I have been playing around with some ideas on how to confine neutrons to the interior of a nuclear reactor. I was wondering if there was a way to capture a emitted neutron from a reaction with a selected isotope that would be...

Homework Statement Q- a positron emerges normally from a 4-mm thick slab of plastic (density= 1.14g/cm^3) with an energy of 1.62 MeV. What is the energy of the particle when it entered the slab? Homework Equations Range when 0< T <= 2.5 MeV: R= .412+T^[1.27-.0954*ln(T)] where T is kinetic...

In order to calculate X and Gamma shielding of I should like use the NIST XCOM online at https://physics.nist.gov/PhysRefData/Xcom/html/xcom1.html In the Xcom tool it is obtained a graph and table of scattering in cm2/g. In order to calculate as example the shielding from 1e19 gamma rays of...

Hello, I need the stopping power for a proton ion gun through Boron-11 sheet 1mm thick. I have the following table obtained from here: https://www-nds.iaea.org/stopping/stopping_hydr.html Where the unit is in 1-15*eV*cm2/atom: Then I calculated for 600keV protons at table 5.1eV*cm2/atom. I...

Homework Statement This a question from an olevel paper and the marking scheme says B I don't understand why Homework Equations None a theory question The Attempt at a Solution Aluminum and copper has less magnetic property while iron is good magnetic material. I cannot understand why the...

Greeting, I am trying to figure out how can I include the activity of a Co-60 source in MCNP code. I have the following problem Co-60 source in a cylinder surrounded by concrete. I just need to know how to include the source activity and whether it should be in Bq or Ci. Thank you in advance

I'm trying to understand if it does exist something (material, construction) that shiled you against alll kind of electromagnetic radiations. Something that shields you from the lowest frequency radio waves up to the highest frequency gamma rays. I've read about faraday cage but it does not...

Hi all, I've only just started studying nuclear physics so forgive me if this question makes no sense. I've read that the way neutron shielding works (in simple terms)is that the neutrons act as billiard balls by knocking into the shielding material atoms and being scattered like this until...

Hi, I am measuring an analog voltage with an Arduino analog in. The analog voltage comes from a cable which also contains digital signal wires. Do I need to separate the analog and digital signals using separate cables? If so, does the analog voltage signal cable need shielding? And if so, how...

Hi all distinguished members of this forum ! As my first post here I would like to open with a situation I have been struggling with I have attached a simple diagram of my problem I have 2 cylindrial N52 neodymium magnets axially aligned with each other with opposite poles facing each other...

I am a lay person, so the physics lesson would only confuse me. I do reloading of ammunition for competitive shooting (Cowboy Action Shooting). I have someone offering to sell lead for melting and casting bullets. He has indicated its source was shielding from hospitals used in X-ray shielding...

Homework Statement Hi, I've got a presentation on an experiment we did using the Helmholtz coil and I'm starting to run dry on material. As some additional applications I found that you can: - Use the coil set up to cancel external interference (Shield other experiments? Not sure about that...

Hi! If water and hydrocarbon rich materials are good at absorbing cosmic radiation, would they also work for shielding muons at sea-level? What about gamma rays and electrons created by muon decay at sea-level...what would be good shields against those? Thanks!

To try to contain a magnetic field in a pair of wires carrying a 6 volt at 2 amp current I twist the wires together. Could a braided shield surrounding those two twisted wires connected to ground help in that process? Using a braided cable such as RG 174 as a audio signal wire with the braid...

Hi. I'd like to show that a conducting, charged spherical shell can shield the field of an inside opposite point charge even if this charge is not at the center. I was thinking about a Gaussian surface just outside the sphere, such that if there were electric field vectors they would be...

Hallo everyone, I have a question about X-Ray shielding in a scanning electron microscope and I hope you can help me! The topic is that when electrons hit the specimen, characteristic radiation up to 10keV is generated. This radiation is blocked/decelerated my the surrounding tower and chamber...

To protect a place from magnetic fields, soft iron is placed around the place, right? so when magnetic field passes through the soft iron, the soft iron becomes an induced magnet, thereby creating induced fields, which makes no sense as the induced fields would still hit the place. please...

Suppose a shield that is infinite in the y and z directions and of thickness 1 meter in the x direction is constructed of alternating layers of materials A and B. Will this shield attenuate a beam of neutrons with more or less or the same attenuation that it would if it were constructed of the...

If I use 10mm (thickness) of a metal for the sides of a Faraday cage, with a 5mm skin depth at the frequency to be shielded, & increase the v/m of the EM wave to be blocked gradually, will there be a stage where the skin depth will increase to 6mm, or is 5mm the maximum limit?

if we have a solid conducting sphere with charges around it, then the elctric field inside the sphere is zero otherwise the electrons of the sphere would not be in equilibrium as there would be a net force acting on it. however if its a hollow sphere then why does the electric field inside the...

Intuitively I always thought He was more expensive than Ar as a shielding gas. But I was reading this book about Heat Exchanger Design & it has this quote that claims "Argon is costlier than Helium" (Link below; see Bullet Point...

(sorry - not sure about the prefix) I have read that lead shielding is dangerous against high energy particle radiation because of the high atomic number in lead. The particles would have high chance of hitting the lead atomic nuclei and producing x-rays. I am fed up with moon landing...

If I surrounded a wire carrying current with a superconductor would the magnetic field from the wire be blocked from the outside?

Hello. Let's say we build the Faraday cage which surround strong radiation such that no radiation can escape to outside world for safety. What happens on external surface of the Faraday cage in voltage during shielding? Is it fluctuated?