Title: Dosimeter for measuring skin dose and more deeply penetrating radiation

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A personnel dosimeter for measuring radiation dose to a wearer within a skin layer defined between density thickness limits comprising:

a holder of thermoplastic material having a front face and a rear wall, said rear wall having an opening therein for access to a plurality of wells;

a plug adapted to seat within said rear wall opening, said plug having a plurality of posts each of which corresponding to one of said plurality of wells to define a plurality of compartments for containing TLD phosphors behind windows of predetermined density thicknesses from the front face of said holder;

a first window, within said front face at a first compartment, having a density thickness of at least about that of the lesser limit of said skin layer but no more than about the deeper limit of said skin layer;

a second window, within said front face at a second compartment, having a density thickness substantially greater than that of said first window and that of the deeper limit of said skin layer, said second window density thickness is greater than that of said first window by at least 5% but no more than 100% of the average density thicness of the phosphors contained within said first and second compartments;

a third window, within said front face at a third compartment, having a density thickness of more than that of said second window and more than that of the average density thickness of the phosphors within said first and second compartments to permit estimation of the dose of penetrating radiation into the body of the wearer and thereby determine the ratio of the net dose passing through said first and said second windows being absorbed within the thickness of phosphors within said first and second compartments whereby radiation dose to said defined skin layer can be determined as a function of said ratio of net dose.

2. The dosimeter of claim 1 wherein said plug within said rear wall is removable to expose TLD phosphors within said plurality of compartments.

3. The dosimeter of claim 1 wherein a fourth window having a density thickness substantially equal to that of said third window is included within said front face at a fourth TLD compartment, said fourth compartment containing a phosphor sensitive to neutrons, beta, gamma and X-radiation.

4. The dosimeter of claim 3 wherein TLD phosphors are disposed in said first, second and third compartments which are sensitive to beta, gamma, and X-radiation but substantially insensitive to neutron radiation.

5. The dosimeter of claim 4 wherein said first, second, and third compartments contain TLD phosphors selected from the group consisting of CaF₂ and Li⁷ F and said fourth compartment contains a TLD phosphor including Li⁶ F.

6. The dosimeter of claim 3 wherein said thermoplastic material contains particles of neutron-absorbing materials including only elements with atomic number less than about 10 distributed throughout the mass of the holder.

7. The dosimeter of claim 6 wherein said neutron-absorbing material is selected from the group consisting of BN, B₄ C, LiF, Li₂ BO₄.

8. The dosimeter of claim 3 wherein there is included within said front face a fifth window having a density thickness equivalent to about that of an average eye lens at a fifth compartment for containing a TLD phosphor.

9. The dosimeter of claim 1 wherein said first window has a density thickness of about 4-10 mg/cm², said second window a density thickness of about 30-100 mg/cm² and said third window a density thickness of about 500-1000 mg/cm².

10. The dosimeter of claim 9 wherein said first window comprises a plastic material selected from the group consisting of polyethylene terephthalate and polycarbonate resins.

11. The dosimeter of claim 10 wherein said first window is of polyethylene terephthalate having an aluminized surface.

12. The personnel dosimeter of claim 1 wherein said holder is formed of a thermoplastic material selected from the group consisting of polypropylene, acrylonitrile-butadienestyrene and polycarbonate resins.


Other info:


Inventors: Jones, Donald E. (Idaho Falls, ID)
Parker, Deray (Idaho Falls, ID)
Boren, Paul R. (Idaho Falls, ID)

Application Number: 06/055211
Filing Date: 1979-07-05
Publication_date: 1981-08-25
Assignee: US ENERGY

Primary Class(es): 250/484.300 250/482.100, 250/486.100, 250/390.030
Other Classes: G01T1/18; G01T1/00; H05B33/00; G01T1/00
US Patent Ref:

3399301	August, 1968	Schayes et al.	250/484	Thermoluminescent dosimeter for detecting radiation having a plurality of components
3761710	September, 1973	Yamashita et al.	250/486	COMPLEX THERMOLUMINESCENCE DOSIMETER

Other Refs: Other References: Gesell et al., "A Personnel Beta-Dosimetry Method for Reducing Energy Dependence", IDO-12090, Mar. 1979.
Charles, "The Development of a Practical 5 mg cm.sup.-2 Skin _Dosimeter", Proc. Fifth International Conf. on Luminescence Dosimetry, Sao Paulo, Brazil, Feb. 14-17, 1977.

Primary Examiner: Willis, Davis L.
Assistant Examiner: Fields, Carolyn E.
Attorney: Glenn, Hugh W.
Jackson, Frank H.
Denny, James E.