Abstract:
A method of assisting with authenticating a workpiece is provided. In another aspect, ions are generated, accelerated in an accelerator, an isotope is created, and then the isotope is implanted within a workpiece to assist with authenticating of the workpiece. A further aspect includes a workpiece substrate, a visual marker and an isotope internally located within the substrate adjacent the visual marker.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/250,609, filed on Nov. 4, 2015, the entire disclosure of which is incorporated by reference herein. 
     
    
     BACKGROUND AND SUMMARY 
       [0002]    The present invention relates generally to isotope tagging and more particularly to isotope tagging for workpiece authentication. 
         [0003]    Artwork forgeries have always posed a problem. Recently, some have theorized that synthetic DNA tagging of paintings or sculptures could possibly provide authentication for artists. This DNA concept, however, may still be prone to copying or altering by sophisticated forgers with scientific knowledge. 
         [0004]    Others have attempted to use chemical or isotope markers. Such conventional constructions are disclosed in: U.S. Pat. No. 8,931,696 entitled “Counterfeit Detection System and Method” which issued to Hood on Jan. 13, 2015; U.S. Pat. No. 8,864,038 entitled “Systems and Methods for Fraud Prevention, Supply Chain Tracking, Secure Material Tracing and Information Encoding using Isotopes and Other Markers” which issued to Marka et al. on Oct. 21, 2014; and U.S. Pat. No. 5,177,360 entitled “Devices and Method to Confirm the Authenticity of Art Objects” which issued to Fernandez-Rubio on Jan. 5, 1993. These prior methods, however, use relatively inexpensive and common isotopes which can be easily obtained by a sophisticated forger with access to common medical laboratories. For example, the Hood patent mixes a liquid form of the marker with paint applied to a canvas or a dye applied to a textile, or weaves a solid form of the marker into clothing. The Marka patent pelletizes the marker for placement into bulk manufactured items. The Fernandez-Rubio patent pipetts the marker into a sealed metal enclosed cavity which is adhered to an art object. Accordingly, these conventional methods are not well suited to prevent sophisticated forgeries of unique, one-of-a-kind items. 
         [0005]    In accordance with the present invention, a method of assisting with authenticating a workpiece is provided. In another aspect, ions are generated, accelerated in an accelerator (for example, a cyclotron), an isotope is created, and then the isotope is implanted within a workpiece to assist with authenticating of the workpiece. A further aspect includes a workpiece substrate, a visual marker and an isotope internally located within the substrate adjacent the visual marker. Another aspect employs one or more isotopes having a half-life of at least three months, a precise and measurable alpha and/or gamma decay emission, and a unique isotope signature. In still another aspect, a system includes a heavy ion source, a cyclotron accelerator, an isotope separator, an optional cryogenic gas stopper, an optional fragmented isotope reaccelerator, and a rare isotope tagging station for tagging a high value workpiece with the rare isotope. Yet a further aspect uses a unique isotope, a pattern of one or more isotopes, and/or a combination of isotopes, to tag a high value workpiece for later authentication. 
         [0006]    The present method, workpiece and system are advantageous over conventional approaches. For example, rare and expensive to produce isotopes are employed which can only be created and implanted in the workpiece in a few expensive facilities, which is well beyond the financial means and technical knowledge of forgers. Furthermore, the present method, workpiece and system allow for extremely accurate and unique authentication and identification tagging or marking. Moreover, the present isotope tagging has a long and predictable lifetime, a precise and measurable decay signature, a unique decay signature, is nonhazardous to people, and will not harm the workpiece. The present method, workpiece and system have the rare isotope implanted within the workpiece after the workpiece is created. Advantageously, the present system implants small quantities of rare isotopes into a workpiece and these isotopes can only be produced by extremely expensive equipment, which are not accessible to forgers. Additionally, the authentication via detection of the decay signatures of the implanted rare ions can be performed completely non-destructively via portable gamma ray detectors with sufficient energy resolution. Additional advantages and features of the present invention will be apparent from the following description and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a diagrammatic view showing superconducting cyclotron equipment used with the present method and system; 
           [0008]      FIG. 2  is an enlarged side elevational view showing the present system including isotopes implanted within a workpiece; 
           [0009]      FIG. 3  is an enlarged back elevational view showing the present system including a visual marker and/or mask located on the workpiece; 
           [0010]      FIG. 4A  is a graph showing predicted rare isotope charge versus isotope neutron number rates expected after completion of the Facility for Rare Isotope Beams; 
           [0011]      FIG. 4B  is a table showing values associated with isotope  64   148 Gd of  FIG. 4A ; 
           [0012]      FIG. 4C  is a table showing values associated with isotope  76   194 Os of  FIG. 4A ; 
           [0013]      FIG. 4D  is a table showing values associated with isotope  26   60 Fe of  FIG. 4A ; 
           [0014]      FIG. 4E  is a table showing values associated with isotope  50   126 Sn of  FIG. 4A ; and 
           [0015]      FIG. 4F  is a table showing values associated with isotope  88   228 Ra of  FIG. 4A . 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    The present method, workpiece and system are shown in  FIGS. 1-3 . A superconducting cyclotron facility  21  includes an ion source  23 , a K500 cyclotron  25 , a K1200 cyclotron  27 , an A1900 fragment separator  29 , a momentum compression ANL gas catcher  31 , an optional cryogenic gas stopper  33 , a low energy beam line EBIT cooler buncher helium jet  35 , an optional linear reaccelerator  37 , and an isotope tagging station  39 . The preceding items are all computer controlled. Ion source  23  includes an electron cyclotron resonance (“ECR”) source or an electron beam ion source (“EBIS”), such a using an ion gun employing microwaves in a low pressure gas or thermionic emissions of electrons to ionize the base material in its gaseous state. Superconducting cyclotron facility  21  is of the type disclosed in Hausmann, M., et al., “Design of the Advanced Rare Isotope Separator ARIS at FRIB,” Nucl. Instr. Meth. B 317 (Jul. 4, 2013) 349-353; and “Experimental Equipment Needs for the Facility for Rare Isotope Beams (FRIB)—whitepaper” (Feb. 13, 2015). Facility  21  uses projectile fragmentation and induced in-flight fission of heavy-ion primary beams at energies of 100 MeV and preferably at least 200 MeV/u and at a beam power of at least 1 kW and preferably at least 400 kW, to generate rare isotope beams. More particularly, reaccelerator  37  is a superconducting—RF driver, linear accelerator. Fragment separator  29  is preferably a three-stage fragment separator including a first stage vertically bending preseparator followed by two horizontally-bending second and third stages using multiple superferric magnet dipoles and quadruples to focus the beam and/or correct image aberrations.  FIG. 1  illustrates the equipment layout of the National Superconducting Cyclotron Laboratory with the proposed location of the isotope tagging station within the accelerator complex, but alternate layouts may be employed. 
         [0017]    A high value workpiece  51  is an original artwork, such as a painting, print, photograph, sculpture, vase, tapestry, document or the like. Alternately, workpiece is an antique, jewelry, watch, vintage automobile component such as an engine block, or other such expensive or one-of-a-kind object that is prone to having forgeries or false reproductions made thereof. In the painting workpiece  51  example used herewith, a substrate  53  is canvas with an aesthetic painted layer  55  on a front surface. If a sculpture, substrate  53  includes the clay or ceramic material. If jewelry or an automobile component, substrate  53  may be a metal structure. 
         [0018]    First, a visual marker  57  is placed in a small area on a backside of workpiece  51 , such as by printing, painting or any other manner which will last for decades without significant degradation or harm to aesthetic painted layer  55 . Marker  57  provides a visual point for the authenticator to begin seeking the isotope tag. One or more metallic masks  59  are temporarily placed against marker  57 . Each mask  59  is a lead plate of about 2-10 mm thick with one or more holes  61  therethrough. Workpiece  51  is then placed in a fixture within isotope tagging station  39 . A hollow and elongated beam pipe  63  is sealed against mask  59 . 
         [0019]    A beam of heavy ions is generated from source  23  and accelerated to approximately half the speed of light by cyclotrons  25  and  27 . Nuclear reactions occur at the beginning of the fragment separator  29  to create the desired isotope. The desired isotope  71  is selected by the fragment separator and then transported for use in a beam pipe or optionally travel through catcher  31  and are slowed down in helium gas stopper  33 . Optionally, isotopes  71  are thereafter re-accelerated in linear accelerator  37  to create a precise workpiece-penetration speed. Isotopes from the fragment separator or optionally reaccelerated isotopes  71  then travel through pipe  63  and those isotopes aligned with holes  61  in mask  59 , penetrate into and are implanted between 5 mm and 1 micron deep, and more preferably at or between 1 mm and 10 microns inside workpiece  51  relative to the backside surface thereof adjacent pipe  63 . 
         [0020]    Multiple masks  59  with different hole quantities or patterns (as shown in  FIG. 3 ) may be employed to provide unique or customized identifiers. Moreover, different combinations of rare isotopes  71  may be implanted through a single or different combinations of mask holes  61  to provide unique or customized identifiers. In the example shown in  FIG. 3 , at least four and more preferably sixteen different isotope locations are provided for a single workpiece. The identifier may be published in a reference guide for each original workpiece. Since a rare isotope is chosen that can only be implanted in expensive accelerator facilities (i.e., &gt;$500 million (2015 USD)), the present approach is too expensive and technically difficult for a forger. However, the present approach is feasible for a physicist with legitimate access to such a system. The authenticator uses a gamma ray detector  73  with keV energy resolution or the like to identify the type of isotope and position of the isotope in a nondestructive manner, to assist in authentication (which includes identification) of the workpiece. 
         [0021]    Referring to  FIGS. 4A-4F , desired rare isotopes are those that are accelerated with an energy of at least 100 A-MeV and with a beam power of at least 1 kW. Furthermore, the desired rare isotopes have a half-life decay rate of at least three months, have a measurable and precise alpha or gamma decay emission (but not a beta decay emission), and have a unique and repeatable isotope signature which cannot be imitated by other isotopes. Nonlimiting exemplary desired isotopes include  64   148 Gd,  76   194 Os,  26   60 Fe,  50   126 Sn,  88   228 Ra,  82   210 Pb, and the like. Other such rare isotopes may be employed beyond those specifically identified. However,  14   32 Si, for example, is not desired since it is a pure beta emitter which makes it difficult to identify the specific isotope due to a lack of unique energies. 
         [0022]    While various embodiments have been disclosed, other embodiments may fall within the scope of the present invention. For example, the mask can have alternate external and/or hole shapes, such as elongated slots of straight or curved shapes. Additional or alternate accelerator, separator, catcher, stopper and jet equipment may be used as long as the facility is not commonly available and can produce rare isotopes accelerated with the above-specified energies and beam powers; such alternate equipment may lead to difference rates of isotope production as compared to  FIGS. 4B-4F  discussed hereinabove. Additional modifications can be made which fall within the scope and spirit of the present invention.