GammaClay

General
This shielding putty was developed as a replacement for our popular lead based shield clay. The putty is manufactured under careful controls to insure that the Bismuth is evenly distributed throughout the material, thus insuring that there will be no holes apparent to the radiation. The material is in the non-soluble form of elemental bismuth (90% by weight). Its density is 3.8 g/ cc or 238 lb/ ft3. It will not dry out and form a powder, and is supplied in convenient size chunks for shaping.

  • Non Hardening
  • Re-usable
  • Lead free

Medical Application
GammaClay can be used to protect patients during orthovoltage x-ray treatments. In this type of treatment, x-rays of several hundred kvp are used to treat localized skin cancers and similar lesions. It is desirable to protect the surface surrounding skin areas from radiation. In the past this was accomplished by cutting lead sheets or casting molten metals into special molds. EnviroClay is readily pliable, yet has enough consistency to hold it's shape after placement. It requires no special tools or techniques to produce patient shields. This material permits accurate, reproduceable technique for obtaining small openings in shields molded to fit patients.

Specification:

The lead is the non-soluble form of elemental lead (87% by weight).

Uses:

  • Temporary gamma shielding.
  • Shielding for cable tray penetrations
  • Radiographic film masking to prevent radiation scatter

Specification
Hydrogen Atoms per cc x 1022:
 
3.3 x 1022
Atoms per cc x 1021 (Additive):
 
9.9 (Bi)
Weight % (Additive):
 
90 (Bi)
lb/ft2:
 
238
Recommended Temperature Limit:
 
110 °F (45 °C)
Machinability:
 
poor
Thermal neutron 1/10” thickness:
 
81.2
Macroscopic Thermal Neutron Cross Section cm-1:
 
0.01
Attenuation Factor for 1” 10/1:
 
1
Gamma x 108R
 
5
Neutrons x 1017 n/cm2:
 
2.5
Density:
 
3.8g/cc (238 lbs/cu ft)
Typical Shielding Thickness (Inch):
 
1.0
Volume % Bismuth:
 
39%
Lead Equivalent Thickness (inch):
 
0.39
   
Element
Pct
Weight atoms/ cc
H
1.44%
3.3E + 22
Bi
90.00%
9.9E + 21
C
8.66%
 
Total 100%
Attentuation Factors at Various Gamma Energies for 1” thickness
0.2 MeV
0.5 MeV
1.0 MeV
19125
4.70
2
 
Approximate Attentuation Factors for 2” (51 mm) thickness:
Source
Attenuation factor
Ir-192
30.20
Cs-137
8.40
Co-60
3.02

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