THEREOF

CROSS-REFERENCE TO RELATED APPLICATIONS

[001] This application claims priority to U.S. Provisional Patent Application No.

62/577,333 filed on October 26, 2017, the entire content of which is hereby incorporated by reference.

BACKGROUND

[002] A seventeen- step protocol to produce bulk cathodes that produce exothermic reactions when irradiated by single and dual laser stimulation is known in the prior art. Three steps in the protocol call for the fabricated cathode to be heated and cooled slowly to ambient temperature over 8-10 hours. The slow-cool method produces a blue-green oxide layer on the cathode, which must be subsequently removed by acid etching with Aqua Regia or other acids suitable for dissolving metal oxides. Cathodes produced by the slow-cool method sometimes fail to produce exothermic reactions in response to laser stimulation. Formation and removal of the oxide layer on the cathode may be responsible for variations in reproducibility of the exothermic reactions. Therefore, there is a need for a method of producing exothermic ally responsive cathodes that avoids formation of oxide layers.

SUMMARY OF THE INVENTION

[003] The present invention avoids oxide layer formation by rapid cooling of the cathode material during the fabrication process. This method produces a cathode free of oxide formation and can receive a light acid treatment to produce a roughened cathode surface.

[004] In one embodiment of the present invention, a method of producing exothermically responsive cathodes may include polishing a surface of a metal billet a first time, rinsing the metal billet with water, heating the metal billet at approximately 750° C for approximately 3 hours, rapidly cooling the metal billet a first time, and roughening the surface of the metal billet with an acid a first time. The method may further include polishing the surface of the metal billet a second time, cleaning the metal billet using an ultrasonic cleaner a first time, annealing the metal billet by heating it at approximately 850° C for approximately 3 hours a first time, rapidly cooling the metal billet a second time, polishing the surface of the metal billet a third time, cleaning the metal billet using an ultrasonic cleaner a second time, and thinning the metal billet using a cold-roller. The method may further include polishing the surface of the metal billet a fourth time, cleaning the metal billet using an ultrasonic cleaner a third time, annealing the metal billet by heating it at approximately 850° C for approximately 3 hours a second time, roughening the surface of the metal billet with an acid a second time, and cleaning the metal billet using an ultrasonic cleaner a fourth time.

[005] In yet another embodiment of the present invention, an exothermically responsive cathode may be prepared by a process including polishing a surface of a metal billet a first time, rinsing the metal billet with water, heating the metal billet at approximately 750° C for approximately 3 hours, rapidly cooling the metal billet a first time, and roughening the surface of the metal billet with an acid a first time. The process may further include polishing the surface of the metal billet a second time, cleaning the metal billet using an ultrasonic cleaner a first time, annealing the metal billet by heating it at approximately 850° C for approximately 3 hours a first time, rapidly cooling the metal billet a second time, polishing the surface of the metal billet a third time, cleaning the metal billet using an ultrasonic cleaner a second time, and thinning the metal billet using a cold-roller. The process may further include polishing the surface of the metal billet a fourth time, cleaning the metal billet using an ultrasonic cleaner a third time, annealing the metal billet by heating it at approximately 850° C for approximately 3 hours a second time, roughening the surface of the metal billet with an acid a second time, and cleaning the metal billet using an ultrasonic cleaner a fourth time.

[006] In yet another embodiment, the metal billet may be comprised of more than one metal.

[007] In yet another embodiment, the metal billet may be comprised of palladium.

[008] In yet another embodiment, polishing the surface of the metal billet may include using an aluminum oxide paste.

[009] In yet another embodiment, polishing the surface of the metal billet may further include using a metal brush.

[0010] In yet another embodiment, rapidly cooling the metal billet may include air quenching by placing the metal billet on a metal block.

[0011] In yet another embodiment, rapidly cooling the metal billet may include placing the metal billet on top of a frozen deuterium oxide block.

[0012] In yet another embodiment, cleaning the metal billet may include using distilled water.

[0013] In yet another embodiment, the acid may comprise Aqua regia.

BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 is a flow diagram of a method for producing exothermically responsive cathodes according to an embodiment of the present invention.

DETAILED DESCRIPTION

[0015] In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. One skilled in the art will recognize that the embodiments of the invention may be practiced without these specific details or with an equivalent arrangement. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the embodiments of the invention.

[0016] The presently disclosed subject matter is presented with sufficient details to provide an understanding of one or more particular embodiments of broader inventive subject matters. The descriptions expound upon and exemplify particular features of those particular embodiments without limiting the inventive subject matters to the explicitly described embodiments and features. Considerations in view of these descriptions will likely give rise to additional and similar embodiments and features without departing from the scope of the presently disclosed subject matter.

[0017] The metallurgical field is familiar with accelerated quenching methods, as discussed in prior art references such as Physical Metallurgy Principles, Second Edition by Robert E. Reed-Hill and Physical Metallurgy, Third Edition by Peter Haasen. Rapid quenching is known to "quench in" vacancies in the metal produced at high temperatures so they remain in the metal at lower temperatures. Further, it is conjectured that deuterium can enter these vacancies to produce exothermic reactions and stabilize the vacancies. Rate of cooling can control the final outcome of the crystal structure of the metal and the crystal structure often determines the level of heat produced by the cathode when stimulated with a laser. The known rapid quenching methods are air, oil, water, and brine. Liquid quenching provides the fastest cool-down and can be done with or without agitation. One of ordinary skill in the art would understand that the methods of the present invention may be practiced with any of the known rapid quenching methods.

[0018] Referring now to FIG. 1, a method of producing exothermically responsive cathodes may comprise polishing a surface of a metal billet a first time 101, rinsing the metal billet with water 102, heating the metal billet at approximately 750° C for approximately 3 hours 103, rapidly cooling the metal billet a first time 104, and roughening the surface of the metal billet with an acid a first time 105. The method may further comprise polishing the surface of the metal billet a second time 106, cleaning the metal billet using an ultrasonic cleaner a first time 107, annealing the metal billet by heating it at approximately 850° C for approximately 3 hours a first time 108, rapidly cooling the metal billet a second time 109, polishing the surface of the metal billet a third time 110, cleaning the metal billet using an ultrasonic cleaner a second time 111, and thinning the metal billet using a cold-roller 112. The method may further comprise polishing the surface of the metal billet a fourth time 113, cleaning the metal billet using an ultrasonic cleaner a third time 114, annealing the metal billet by heating it at approximately 850° C for approximately 3 hours a second time 115, roughening the surface of the metal billet with an acid a second time 116, and cleaning the metal billet using an ultrasonic cleaner a fourth time 117.

[0019] During the thinning step 112, the cold-roller is used to reduce the thickness of the metal billet to approximately 0.25 mm. The thickness of the metal billet will be further reduced during acid etching in step 116, and finished cathodes less than 0.20 mm thickness tend to curl from the stresses of loading.

[0020] During the cleaning steps 107, 111, 114, the metal billet may be placed

[0021] In yet another embodiment, the metal billet may be comprised of more than one metal. The metal billet does not need to be comprised of a single metal. Metals such as copper, gold, or platinum may be over plated with doped palladium and/or gold to form the metal billet and achieve the same results.

[0022] In yet another embodiment, the metal billet may be comprised of palladium.

[0023] In yet another embodiment, polishing the surface of the metal billet may include using an aluminum oxide paste.

[0024] In yet another embodiment, polishing the surface of the metal billet may further include using a metal brush.

[0025] As discussed above, rapid cooling may be achieved using any of the known rapid quenching methods known in the art. In one embodiment, rapidly cooling the metal billet may include air quenching by placing the metal billet on a metal block. After heating, the metal billet is rapidly removed from the heat source with a pair of tongs and placed on a stainless steel or aluminum block for rapid cooling to ambient temperature. The cooling block may be comprised of any other highly conductive metal. Variations of this method are to chill the metal blocks to freezing or below. In yet another embodiment, rapidly cooling the metal billet may include placing the metal billet on top of a frozen deuterium oxide block. The rapid melting of the deuterium oxide provides agitation of the cathode surface, cooling the cathode at a faster rate. This produces a cathode without the oxide layer and retains the increased concentration of vacancies produced during heating. The frozen deuterium oxide block may be used in combination with the metal cooling block to achieve more rapid cooling.

[0026] In yet another embodiment, cleaning the metal billet may include using distilled water.

[0027] In yet another embodiment, the acid may comprise Aqua regia.

[0028] The above description and drawings are illustrative and are not to be construed as limiting the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description.

[0029] Reference in this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments.

[0030] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise," "comprising," and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to." As used herein, the terms "connected," "coupled," or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling of connection between the elements can be physical, logical, or any combination thereof. Additionally, the words "herein," "above," "below," and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word "or," in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0031] The teachings of the disclosure provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.

[0032] These and other changes can be made to the disclosure in light of the above

Detailed Description. While the above description describes certain embodiments of the disclosure, and describes the best mode contemplated, no matter how detailed the above appears in text, the teachings can be practiced in many ways. Details of the system may vary

considerably in its implementation details, while still being encompassed by the subject matter disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the disclosure should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the disclosure with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the disclosure to the specific embodiments disclosed in the

specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the disclosure encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the disclosure under the claims.

[0033] The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Certain terms that are used to describe the disclosure are discussed above, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the disclosure. For convenience, certain terms may be highlighted, for example using capitalization, italics and/or quotation marks. The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that same element can be described in more than one way.

[0034] Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any exemplified term. Likewise, the disclosure is not limited to various embodiments given in this specification.

[0035] Without intent to further limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.

[0036] Some portions of this description describe the embodiments of the invention in terms of algorithms and symbolic representations of operations on information. These algorithmic descriptions and representations are commonly used by those skilled in the data processing arts to convey the substance of their work effectively to others skilled in the art. These operations, while described functionally, computationally, or logically, are understood to be implemented by computer programs or equivalent electrical circuits, microcode, or the like. Furthermore, it has also proven convenient at times, to refer to these arrangements of operations as modules, without loss of generality. The described operations and their associated modules may be embodied in software, firmware, hardware, or any combinations thereof.

[0037] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

[0038] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the presently disclosed subject matter pertains. Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the presently disclosed subject matter, representative methods, devices, and materials are now described.

[0039] Following long-standing patent law convention, the terms "a", "an", and "the" refer to "one or more" when used in the subject specification, including the claims. Thus, for example reference to "an additive" can include a plurality of such additives, and so forth.

[0040] Unless otherwise indicated, all numbers expressing quantities of components, conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the instant specification and attached claims are

approximations that can vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter.

[0041] As used herein, the term "about", when referring to a value or to an amount of mass, weight, time, volume, concentration, and/or percentage can encompass variations of, in some embodiments +/-20%, in some embodiments, +/-10%, in some embodiments +1- 5%, in some embodiments +/-1%, in some embodiments +/-0.5%, and in some embodiments, +/-0.1%, from the specified amount, as such variations are appropriate in the disclosed products and methods.