there is a rad in the castle

[Boris]

Hi,

Just out of curiosity, I lined the inside of my lead-castle with a radpad.
A radpad is a disposable sheet of material, used to cover a patient while performing surgery under X-ray.
The beam form the x-ray machine itself will not affect the medical staff, because it is a straight line from tube to detector.
The scattering of the x-rays occurs when a patient is between the beam and the detector, and this is always the case.
If possible medical staff should always minimize the exposure to themselves (alara), (and patient) but when performing a procedure they stand often very close to the patient.
This is why they cover parts of the patient with this radpad.
It consist of a polymer with probably bismuth and possibly tungsten granulate.
I lined the inside of my lead castle with a used radpad and noticed that the background radiation (from the lead) drops from 5,99 cps to 4,43 cps.
Not bad for only 3 mm of material, I think i'm going to add more layers to the lead cake....

In the attachment part of the spectrum with and without radpad.
My shield consist of: 7 cm of lead (PB), 3 mm of copper(CU) and 12 mm of aluminium.

Cheers, Boris.

[Sesselmann]

Boris,

Thanks for sharing. It looks like the Radpad does a pretty good job of shielding the low energy x-rays, so I guess it does what it is designed for.

What do these Radpads cost and where would one go to buy some?

Steven

[Mark Rowley]

Thats pretty interesting Boris. I have many friends that work in the medical profession. I will have to ask about it.

[Boris]

Steven, as Mark suggested, have friends in the medical circuit...radpad cost about 50 euro's a piece.

and then are thrown in the bin after use...

some info on the used materials, stibium (Sb) Barium (Ba) and bismuth (Bi).
One of the hospitals studied the use and made a report for internal use, they stated that the composition of material converts "radiation into heat"and not into rem radiation...I do not know what makes this special, as I presume this is always the case, but correct me if i'm wrong...

I'm going to collect more radpads and add more layers to the cake....
and post a report if I have mode data....

it would be a nice portable shielding....

Kind regards, Boris.

[Boris]

Hi all.

Just added some layers of radpad to the lead castle, the empty castle measures about 3,3 cps now.
the problem with the radpads is that no glue will stick to them..the solution is more beautifully than the problem...

please, do not do this at home! take health and safety measures!

I noted that the plastic component of the sheet material inside the radpad will melt at about 130 C, and it becomes very soft.
Made a disk shape casting mould and heated it up to about 130 C, put all the little scrap bits in it and in melted into a beautiful metallic plastic disk.
Very easy to work with it is amazing...it sprinkled a load of ideas in my head.

At this moment i´m planning on making a cast mould for the bottom of the shield, and rings to stack on to that.


Pictures will be posted. time is needed to collect the materials....keep you posted, Cheers Boris.

[Sesselmann]

Boris,

This sounds interesting, looking forward to seeing pictures.

How rigid is this material after melting, at 130˚C it sounds almost like wax.

Steven

[Boris]

strange conclusion..or no conclusion....

As a got some more pads, melted some to form the top an bottom in the shield, and used 8 of them rolled up in the castle.
First I did a test with none and also removed the inner part (a aluminium fire extinguisher tank).
to my surprise the total count rate dropped to about 3,7 it seems that the aluminium cylinder contains some elements that radiate a bit.
Then added the 8 rad pads and noticed that the rate only dropped to 3,2.
This is not confirming my earlier findings...
True that the 0-150 Kev is attenuated, so I'm planning on some experiment's if I can find the time this weekend...

Cheers, Boris.

[Boris]

Oh almost forgot, outside the castle it is about 60 cps, when I use the radpad shield it drops to 40 cps.
so for mobile use maybe?
I think I need to collect more to make a 2cm shield of them....
cheers, Boris.

[Sesselmann]

That looks quite neat. So you melted the bits in a mould to make a doughnut, I was thinking of doing a similar mould to make lead doughnuts.

How heavy is this material ?

What would be the half value layer for the radpad?

https://en.wikipedia.org/wiki/Half-value_layer

[Taray]

Boris,
Radpad will block bg radiation depending on the number of layers or grade used.
Even a thin sheet of lead ,tin or bismuth or alloy will also produce lower bg rates.Does not have to be radpad.Radpad is made to block backscatter radiation during radiological procedures.Radpad  materials were chosen for lightweight  properties since they are to be placed on patients.I use radpad in my lead shield too but for a different purpose.I cover the outside of my lead shields to block xrf's from hitting me .Not to reduce bg radiation within.I stick to lead blocks with some copper within and cadmium just beside my detector to cut off Pb xrf peaks somewhat.
Radpad from my xrf studies show antimony with possibly some bismuth.I don't have any papers showing their nature.It is for xrf analysis.
I will post my detailed xrf studies later on.My pc internet is down
Ok I am back.
Taray