Nickel-coated lead

How to build the perfect shield for your measurements? Discuss it here!
User avatar
MartinM
Posts: 42
Joined: 21 Apr 2016, 18:12
Contact:

Nickel-coated lead

Post by MartinM » 27 Jun 2016, 06:44

Hi,

I'm building my shielding - a 65mm copper tube covered with tin sheets. The inner part:
IMG_6925.JPG
IMG_6925.JPG (826.53 KiB) Viewed 4299 times
IMG_6927.JPG
IMG_6927.JPG (1.11 MiB) Viewed 4299 times
Outer part is a 125mm PVC tube.
I found a supply of 2.5mm lead granules that are Nickel coated. What do you think about using this for shielding? Would the Nickel coating provide even better Beta-shielding, or could it have additional adverse effects like generating more XRF ?
Martin Malik, http://www.hwinfo.com

User avatar
Steven Sesselmann
Posts: 626
Joined: 27 Apr 2015, 11:40
Location: Sydney
Contact:

Re: Nickel-coated lead

Post by Steven Sesselmann » 27 Jun 2016, 18:08

Nickel should be okay, most of the x-Ray's are under 10 Kev.

http://nucleardata.nuclear.lu.se/toi/xr ... list&el=Ni

Steven
Steven Sesselmann | Sydney | Australia | gammaspectacular.com | groundpotential.org | rephopper.com | beejewel.com.au |

User avatar
MartinM
Posts: 42
Joined: 21 Apr 2016, 18:12
Contact:

Re: Nickel-coated lead

Post by MartinM » 31 Jul 2016, 20:14

I have finally finished my shielding.
Height: 47 cm, outer diameter 12.5 cm, total weight ~24 kg. Filled with ~3 cm of Pb.
The plug is a 60mm tube also filled with lead granules and Sn + Cu plates.
Thinking about some kind of upper plug, perhaps just some thick (~3 cm) Cu cube placed on the top to avoid extensive machining.
IMG_7210.JPG
IMG_7210.JPG (1.03 MiB) Viewed 4223 times
IMG_7211.JPG
IMG_7211.JPG (420.16 KiB) Viewed 4223 times
IMG_7212.JPG
IMG_7212.JPG (1.41 MiB) Viewed 4223 times
Will follow up with some measurements shortly.
Martin Malik, http://www.hwinfo.com

User avatar
MartinM
Posts: 42
Joined: 21 Apr 2016, 18:12
Contact:

Re: Nickel-coated lead

Post by MartinM » 31 Jul 2016, 20:29

Background count reduced from 100-120 cps to 10-15 cps.
shield.png
shield.png (5.71 KiB) Viewed 4223 times
Martin Malik, http://www.hwinfo.com

User avatar
MartinM
Posts: 42
Joined: 21 Apr 2016, 18:12
Contact:

Re: Nickel-coated lead

Post by MartinM » 31 Jul 2016, 21:17

Here a rather short test of Cs137 calibration source.
Cs137.png
Cs137.png (7.46 KiB) Viewed 4223 times
No significant Pb XRF seen. Note the unexpectedly low resolution of 6.3%
Martin Malik, http://www.hwinfo.com

User avatar
Steven Sesselmann
Posts: 626
Joined: 27 Apr 2015, 11:40
Location: Sydney
Contact:

Re: Nickel-coated lead

Post by Steven Sesselmann » 01 Aug 2016, 07:32

Excellent build, well thought out and nice result. The Pb x-ray is not even visible in the spectrum.

Note: Great resolution, but you need to select a bit wider region of interest to see the true resolution. Just a few more bins each side where it flares out,
Steven Sesselmann | Sydney | Australia | gammaspectacular.com | groundpotential.org | rephopper.com | beejewel.com.au |

User avatar
Stanford
Posts: 10
Joined: 22 Sep 2016, 03:06
Location: Port Townsend, WA USA
Contact:

Re: Nickel-coated lead

Post by Stanford » 23 Sep 2016, 02:57

How about copper coated lead shot for the same reason?

Steven Sesselmann wrote:Nickel should be okay, most of the x-Ray's are under 10 Kev.

http://nucleardata.nuclear.lu.se/toi/xr ... list&el=Ni

Steven
Stanford Siver

User avatar
MartinM
Posts: 42
Joined: 21 Apr 2016, 18:12
Contact:

Re: Nickel-coated lead

Post by MartinM » 23 Sep 2016, 03:56

Stanford wrote:How about copper coated lead shot for the same reason?

Steven Sesselmann wrote:Nickel should be okay, most of the x-Ray's are under 10 Kev.

http://nucleardata.nuclear.lu.se/toi/xr ... list&el=Ni

Steven
Similar as Cu - below 10 keV.
Martin Malik, http://www.hwinfo.com

User avatar
Stanford
Posts: 10
Joined: 22 Sep 2016, 03:06
Location: Port Townsend, WA USA
Contact:

Re: Nickel-coated lead

Post by Stanford » 23 Sep 2016, 14:16

Super thank you...

I just read that "commercially available lead often contains a significant fraction of antimony, as that helps its material properties (the antimony makes it harder, easier to cast in molds, etc.). But antimony is one of the last materials you'd want in a radiation shield, as it is highly vulnerable to induced radioactivity; that is, being bombarded by gamma rays transmutes the antimony into other radioactive isotopes. Some amount of induced radioactivity is inevitable, but you certainly don't want to have more than the absolute minimum, so lead for shielding has to be very pure.

Is this right? And is antimony free lead shot available?
MartinM wrote: Similar as Cu - below 10 keV.
Stanford Siver

User avatar
MartinM
Posts: 42
Joined: 21 Apr 2016, 18:12
Contact:

Re: Nickel-coated lead

Post by MartinM » 23 Sep 2016, 16:11

I don't think that such induced radioactivity can occur in common conditions. It would require high-energy gamma rays which are usually only artificially produced (accelerators, etc.), or other particles like alpha or neutrons that are unlikely to reach the material or occur in sufficient quantity.
But perhaps someone else can better comment on this.
Martin Malik, http://www.hwinfo.com

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest