This invention involves a radiation absorber that is constructed from multiple layers. The layers each have specific purposes in controlling radiation intensity and or in making the absorber more effective to install and use. Layer additives may be mixed together.
It is often advantageous to reduce and control the intensity of radiation fields in those cases where the uncontrolled radiation may be harmful to animals or interfere with the operation of equipment. In other cases it is important to absorb unwanted radiation that would otherwise interfere with the intended operation of measurement equipment. This invention defines the construction of multi component radiation shields that more effectively and efficiently control fields of radiation that may otherwise create unwanted radiation exposures. In the case of this invention, radiation will be assumed to be either ionizing radiation or acoustic radiation.
An absorber is constructed from two or more layers of polymer that itself exhibits absorptive, scattering or attenuating properties or from layers of a polymer that carries an absorptive element or a plurality of elements as a filler or fillers useful in controlling the radiation being targeted to control. This invention also describes absorbers that are constructed in two or more layers with each layer having a differing functional use in the performance of the radiation attenuation task. Typically each functional or absorptive layer is constructed of a rubber like material as a natural or synthetic rubber, latex, natural or synthetic polymer, elastomer, thermoplastic, or otherwise flexible member combined with an absorptive element or plurality of elements. This layer is then formed into the desired useful shape required by the application using conventional filled polymer forming processes. These processes include but are not be limited to, rolling, extruding, spraying, casting, or otherwise molding the layer into a shape useful in the application. The polymer set into its final shape using conventional polymer setting processes of cooling for thermoplastics, heating for thermosetting materials, polymerization by the admixing of polymerization accelerators, or by external reaction by polymerization accelerators, or other such techniques. Shapes may be regular as tapes, sheets, or cylinders, or be of specialty shapes as required by the shielding application. In each case this layer is combined with at least one other layer having a differing composition, radiation shielding, or installation fastening function. This second layer is also added using conventional forming processes of adhering, molding, rolling, spraying, calendaring, casting or similar processes. In all cases the finished article is functional and can be handled as a single component. In some cases one layer may utilize a similar matrix and absorptive filler as the next, differing only by the inclusion of an additional element. Layers need not be planar, but rather may be granular where the radiation absorption relies on the local availability of one layer to the next.
The invention is used by placing the absorber in between the radiation source and the item to be shielded or protected. It may be also installed as part of the item to be shielded, or used a either a permanent or temporary cover or shield for the item.
The concepts described in these figures can also be mixed or combined to create specialty multi layer or multi-zoned absorbers tailored to a particular use application. In the specific case of the absorption of acoustic radiation, controlled zones of differing acoustic properties can be designed into the multilayer absorber to suit the intended purpose.