Patent Number: 
Section: claims

1. A radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope wherein said substrate is flexible. 2. The radiation source according to  claim 1 , wherein said substrate is made of one of paper and plastic. claim 1 3. A radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, wherein said substrate is flexible, said substrate has a first form factor when contained within said outer housing, and said substrate is manipulable to have a second form factor smaller than said first form factor when said substrate is removed from said outer housing. 4. A radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, wherein at least a portion of said radioactive deposit has at least two layers. 5. The radiation source according to  claim 4 , wherein an activity density of each of said at least two layers is the same. claim 4 6. A radiation source comprising; an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, wherein said substrate is radiopaque. 7. A radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, wherein said radioactive deposit includes a colorant. 8. The radiation source according to  claim 7 , wherein a color of a portion of said radioactive deposit corresponds to an activity level of said portion of said radioactive deposit. claim 7 9. A radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, wherein said radioactive deposit includes a binding agent for fixedly depositing said radioactive deposit on said front surface. 10. A radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, wherein said radioactive deposit is fixedly deposited upon said front surface by covering said radioactive deposit and said front surface with a sealing layer. 11. A radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, further including a second substrate with a second radioactive deposit deposited thereon, said second substrate being contained within said outer housing. 12. The radiation source according the  claim 11 , wherein the combination of said radioactive deposit and said second radioactive deposit produces a desired radioactive deposit. claim 11 13. A radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, wherein said radioactive deposit has a substantially uniform activity distribution. 14. A radiation source for calibration of nuclear imaging equipment, said radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a flexible substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, a binding agent, and a colorant, wherein  at least a portion of said radioactive deposit has at least two layers, each layer having substantially the same activity density, and  a color of a second portion of said radioactive deposit indicates the activity level of said portion of said radioactive deposit. 15. A radiation source for calibration of nuclear imaging equipment, said radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a flexible substrate removably contained within said outer housing, said substrate having a front surface;  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, and a colorant; and a sealing layer covering said radioactive deposit and said front surface of said substrate, wherein  at least a portion of said radioactive deposit has at least two layers, each layer having substantially the same activity density, and  a color of a second portion of said radioactive deposit indicates an activity level of said second portion of said radioactive deposit. 16. A nuclear imaging system, comprising: a piece of nuclear imaging equipment to be calibrated; and  a radiation flood source to calibrate the piece of nuclear imaging equipment including,  an outer housing having a fastener, said outer housing configured to be opened,  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, further including a second substrate with a second radioactive deposit deposited thereon, said second substrate being contained within said outer housing. 17. A nuclear imaging system, comprising: a piece of nuclear imaging equipment to be calibrated; and  a radiation flood source to calibrate the piece of nuclear imaging equipment including,  an outer housing having a fastener, said outer housing configured to be opened,  a substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, wherein the combination of said radioactive deposit and said second radioactive deposit produces a desired radioactive result. 18. A radiation source for calibration of nuclear imaging equipment, said radiation source comprising: an outer housing having a fastener, said outer housing configured to be opened;  a flexible substrate removably contained within said outer housing, said substrate having a front surface; and  a radioactive deposit fixedly deposited upon said front surface within said outer housing, said radioactive deposit having a radioisotope, a binding agent, and a colorant, wherein  said substrate has a first form factor when contained within said outer housing, and said substrate is manipulable to have a second form factor smaller than said first form factor when said substrate is removed from said outer housing;  at least a portion of said radioactive deposit has at least two layers, each layer having substantially the same activity density, and  the color of a portion of said radioactive deposit indicates the activity level of said portion of said radioactive deposit.