Blocking Radiation

BenTC · Post by **BenTC** » Wed Jan 20, 2010 1:25 pm

On this page http://www.chemicalforums.com/index.php?topic=5389.0
someone asks "What makes lead so good at blocking radiation? Does it have to do with the structure it takes in its solid form?" and gets the response "Lead has a high density of electrons"

Just speculating... what is the relative density of electrons inside a capacitor compared to lead, and could highly charged parallel plates provide similar blocking of the radiation ?

MSimon · Post by **MSimon** » Wed Jan 20, 2010 3:06 pm

BenTC · Post by **BenTC** » Wed Jan 20, 2010 3:40 pm

blaisepascal · Post by **blaisepascal** » Wed Jan 20, 2010 6:33 pm

BenTC wrote:k.

Run the numbers.

Lead is Atomic Number 82, an atomic weight of 207, and a density of 11.35 g/cm^3. A mol of lead masses 207 g, a volume of about 18cm^3, and contains 82 * 6.022x10^23 electrons. That works out to 2.7x10^24 electrons per cubic centimeter.

A coulomb of charge is the charge of about 6.2x10^18 electrons, so the electron charge in 1 cm^3 of lead would be about -440,000 coulombs (balanced, of course, by an equal positive charge from the protons.

Got any capacitors which can pack that charge into a cubic centimeter?

Tom Ligon · Post by **Tom Ligon** » Wed Jan 20, 2010 8:40 pm

Lead also has a dirty little secret as a radiation shield. It is counterproductive when dealing with betas (high-energy electrons). Those will produce x-rays when they strike high-Z nuclei or encounter all those shells of electrons.

For betas you want something low-Z, like a layer of plastic.

OSHA may want you to cover up the lead anyway.

DeltaV · Post by **DeltaV** » Wed Jan 20, 2010 10:22 pm

If Widom and Larsen have a correct theory for LENR, maybe there's application to radiation shielding:

"Absorption of Nuclear Gamma Radiation by Heavy Electrons on Metallic Hydride Surfaces"

http://www.newenergytimes.com/v2/librar ... rGamma.pdf

kunkmiester · Post by **kunkmiester** » Thu Jan 21, 2010 12:01 am

I understand an ideal cosmic radiation shield would be a couple inches of lead or something, AND a couple of yards or more of foam or something like that.

This is a bit easier than it seems, depending on your ship design. I'm thinking of a modular design centered around a central truss. The entire thing would be coated with foam, with viewing portals and sensors reaching through. This might actually make up the bulk of the mass, depending on how you build your ship.

MSimon · Post by **MSimon** » Thu Jan 21, 2010 1:05 am

kunkmiester wrote:I understand an ideal cosmic radiation shield would be a couple inches of lead or something, AND a couple of yards or more of foam or something like that.

This is a bit easier than it seems, depending on your ship design. I'm thinking of a modular design centered around a central truss. The entire thing would be coated with foam, with viewing portals and sensors reaching through. This might actually make up the bulk of the mass, depending on how you build your ship.

The most important secret in the Naval Nuke community had nothing to do with reactor design. It was how the shielding was designed. Fortunately I am unable to remember a thing about it.

What is open knowledge is that the Russian Subs give their personnel high radiation doses and the American subs low doses.

It is all about optimizing volumes and weights.

When ever a TV crew visits Boomer Nuke Subs you will notice that visits to the rocket launch area are are prominent but you never see the reactor area.

djolds1 · Post by **djolds1** » Thu Jan 21, 2010 4:53 am

MSimon wrote:The most important secret in the Naval Nuke community had nothing to do with reactor design. It was how the shielding was designed. Fortunately I am unable to remember a thing about it.

Ummmhmmm. Yeah. Riiiiiiiight.

MSimon · Post by **MSimon** » Thu Jan 21, 2010 5:06 am

djolds1 wrote:
MSimon wrote:The most important secret in the Naval Nuke community had nothing to do with reactor design. It was how the shielding was designed. Fortunately I am unable to remember a thing about it.
:twisted:

Ummmhmmm. Yeah. Riiiiiiiight. :)

It was not a subject that interested me and it has been almost 45 years. All I remember is that I was sworn to not give details.

djolds1 · Post by **djolds1** » Thu Jan 21, 2010 6:27 am

MSimon wrote:
djolds1 wrote:

Ummmhmmm. Yeah. Riiiiiiiight.
It was not a subject that interested me and it has been almost 45 years. All I remember is that I was sworn to not give details.

Nor would I dream of asking you for said details. Some lines are not crossed, ever; allegiance matters. Beyond that, learn to laugh Simon - the emoticons were supposed to clue you.

MSimon · Post by **MSimon** » Thu Jan 21, 2010 6:59 am

djolds1 wrote:
MSimon wrote:
djolds1 wrote::twisted:

Ummmhmmm. Yeah. Riiiiiiiight. :)
It was not a subject that interested me and it has been almost 45 years. All I remember is that I was sworn to not give details.
Nor would I dream of asking you for said details. Some lines are not crossed, ever; allegiance matters. Beyond that, learn to laugh Simon - the emoticons were supposed to clue you. :wink:

Well yeah. But do you know what was going through my mind? Being brought up on charges. Nothing like the threat of hanging to concentrate the mind.