Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Examiner reached out to Applicants for an election between apparatus and method claims. No election was made prior to Examiner’s deadline for this case. Accordingly, all claims 14–23 are examined herein. Examiner reserves the right to issue a future restriction/election requirement if Applicant adds/amends claims at a later date that are distinct and/or mutually exclusive from this original presentation or from each other. Additionally, Examiner reserves the future right under election by original presentation to withdraw claims amended/added to embodiments not originally examined—see MPEP § 821.03.
Claim Rejections - 35 USC § 101
35 U.S.C. 101 reads as follows:
Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.
Claims 14–23 are rejected under 35 U.S.C. 101 because the claimed invention is not supported by a well-established utility or a substantial and credible asserted utility.
In Brenner v. Manson, the Supreme Court stated that “[t]he basic quid pro quo contemplated by the Constitution and the Congress for granting a patent monopoly is the benefit derived by the public from an invention with substantial utility. Unless and until a process is refined and developed to this point—where specific benefit exists in currently available form—the is insufficient justification for permitting an applicant to engross what may prove to be a broad field.” 383 U.S. 519, 534-35 (1966). The Manual of Patent Examining Procedure (MPEP) accordingly explains that the purpose of the utility requirement is “to limit patent protection to inventions that possess a certain level of ‘real world’ value, as opposed to subject matter that represents nothing more than an idea or concept, or is simply a starting point for future investigation or research.” MPEP § 2103, A., I.
Thus, the USPTO has the initial burden of setting forth a reason to doubt an Appellant's presumptively correct assertion of utility. In re Swartz, 232 F.3d 862, 864 (Fed. Cir. 2000). “The PTO may establish a reason to doubt an invention's asserted utility when the written description ‘suggest[s] an inherently unbelievable undertaking or involve[s] implausible scientific principles.”’ In re Cortright, 165 F.3d 1353, 1357 (Fed. Cir. 1999) (quoting In re Brana, 51 F.3d 1560, 1566 (Fed. Cir. 1995)).
Here, the claims are directed to an approach to self-sustaining nuclear fusion:
claims 14 and 17 recite a fusion reactor (tokamak) with an input power of “preferably less than 10 MW” (claim 16) but that has a net output power (“fusion energy gain factor Q>1, Q>10, Q>50,” claims 18-20).
The language Q>1, Q>10, and Q>50 in claims 18-20 requires that the nuclear fusion reactions occurring with the reactor are self-sustaining, also known in the art as achieving ignition or breakeven, all meaning net-energy production where more power is output than was input.1
In the background paragraphs of the Specification2 (¶¶ 4–11), Applicant acknowledges how all previous attempts at achieving breakeven fusion have failed:
“However, ITER's scalability calls for alternative power and particle exhaust techniques, critical for the success of tokamak-based fusion power plants,” ¶ 4
“Spherical Tokamaks (STs) offer an alternative path … However, the high-power densities achievable in STs impose even more stringent constraints on their Plasma Facing Components (PFCs) compared to conventional tokamaks, necessitating alternative power and particle exhaust techniques for an ST-based fusion pilot plant (FPP). Moreover, due to their compactness, standard STs suffer an important challenge to accommodate in the center stack the coils system, neutron shielding and tritium breeding blanket,” ¶ 5
“While the ITER baseline scenario, a high confinement mode (H-mode) with tolerable plasma-wall interaction, has been demonstrated in most present tokamaks, its applicability to a future fusion power plant remains uncertain,” ¶ 6
“The primary challenge lies in proving that a fusion plasma can be self-heated and sustained by thermonuclear reactions in an economical tokamak configuration,” ¶ 6
“Unfortunately, tokamak fusion plasmas in H-mode tend to develop magnetohydrodynamic (MHD) fluctuations that hinder the steady-state operation that is crucial,” ¶ 7
Despite the failure of all others hitherto, Applicant claims to have overcome the tremendous barriers known in the art and invented an apparatus for producing net-energy nuclear fusion that provides “a fast and cost-effective alternative for establishing a commercial fusion power plant,” Specification at ¶ 3. Applicant’s specific asserted utility is disclosed in the Specification at ¶ 32 and ¶ 40: the world’s first-ever net-energy producing nuclear fusion reactor whose power output is not just greater, but enormously so, than its power input:
“The present invention introduces … fusion energy as a viable energy source …. This configuration delivers a power input to the plasma less than 100 MW, preferably less than 10 MW. And the tokamak 1 is operated at a fusion energy gain factor Q>1, preferable Q>10, more preferable Q>50.”
The inventive fusion is further explicit per its net energy gain in claims 18 (“fusion energy gain factor Q>1”), claim 19 (“fusion energy gain factor Q>10”), and claim 20 (“fusion energy gain factor Q>50”).
Presently available publications evidence a consensus in the scientific community that there is yet to be a fusion technique capable of producing an energy gain sufficient for practical applications. As noted by Dylla,3 as recently as 2020, the largest nuclear fusion project in the world—the International Thermonuclear Experimental Reactor (ITER)—aspired to achieve a successful fusion demonstration “for several minutes duration” by 2026 at the absolute earliest. This is with a projected cost of “greater than $10 billion.”
Further according to the official ITER4 webpage:
“The world record for fusion power in a magnetic confinement fusion device is held by the European tokamak JET. In 1997, JET produced 16 MW of fusion power from a total input heating power of 24 MW (Q=0.67). ITER is designed to yield in its plasma a ten-fold return on power (Q=10), or 500 MW of fusion power from 50 MW of input heating power. ITER will not convert the heating power it produces as electricity, but — as the first of all magnetic confinement fusion experiments in history to produce net energy gain across the plasma (crossing the threshold of Q≥1) — it will prepare the way for the machines that can.”
There currently exist no nuclear fusion reactors capable of producing useful energy gain for practical applications. The National Ignition Facility (NIF) is the largest operational fusion system in the US to date that operates at extreme temperatures. In December 2022, the NIF reportedly achieved a “nuclear fusion breakthrough,” producing 3.15 MJ of fusion energy from 2.05 MJ of laser light. This was the first ever demonstration in the world of a target producing more energy than was delivered to the target. However, the laser system5 itself required 322 MJ of energy to create these fusion reactions, multiple orders of magnitude greater than the energy produced. Thus, while an achievement in fusion, the experiment is far from a demonstration of practical energy production—as stated by experts in the fusion community.6,7
When the most advanced thermonuclear fusion reactors in the world have yet to create more energy than they consume (“net” energy gain), Applicant’s claims to be in possession of a nuclear fusion apparatus that operates so efficiently as to be “a fast and cost-effective alternative for establishing a commercial fusion power plant,” Specification at ¶ 3, would be found questionable to a person of ordinary skill in the art.
Overcoming the Coulomb barrier to achieve critical ignition for nuclear fusion is only known to occur at extremely high kinetic energies, i.e., extremely high temperatures, such as those present on the sun. Georgia State University8 explains:
“The temperatures required to overcome the coulomb barrier for fusion to occur are so high as to require extraordinary means for their achievement. Such thermally initiated reactions are commonly called thermonuclear fusion. With particle energies in the range of 1-10keV, the temperatures are in the range of 107–108 K.”
Applicants have failed to sufficiently disclose how the claimed fusion reactor is capable of achieving and sustaining a fusion reaction to achieve the breakeven conditions necessary for “establishing a commercial fusion power plant.”
For the present invention, which is directed to a new design for a self-sustaining nuclear fusion reactor, a concept at odds with conventional best practices, evidence and acceptance by the scientific community is of crucial importance because the PTO may meet its burden to establish a prima facie case of lack of utility where the written description suggests an unbelievable undertaking or implausible principles. See In re Cortright, 165 F.3d. at 1357.
The claimed invention—a type of nuclear fusion reactor in its early days of research9—for generating and maintaining a fusion reaction sufficient to be used as a viable energy source is too undeveloped to be considered to have a body of existing knowledge associated with it, much less reproducibility of results. See In re Swartz, 232 F.3d at 864 (“Here the PTO provided several references showing that results in the area of cold fusion were irreproducible. Thus the PTO provided substantial evidence that those skilled in the art would ‘reasonably doubt’ the asserted utility and operability of cold fusion”). Reproducibility must go beyond one’s own laboratory. One must produce a set of instructions—a recipe—that would enable a skilled artisan to produce and use the invention. If reproducibility occurs only in one’s own laboratory, errors (such as systematic errors) could reasonably be suspected. Applicant’s disclosure is insufficient as to how the embodiments described therein are based upon valid and reproducible methodology.
The Examiner cannot find, and Applicant has not supplied, any reputable and peer-reviewed papers in which the mainstream scientific community (i.e., outside of Applicant’s own laboratory/computer simulations) has replicated or built upon Applicant’s purportedly revolutionary discovery. Therefore, the Examiner must conclude that the claimed invention has not been independently reproduced.
In view of the above, it is more likely than not that an ordinarily skilled artisan would doubt the effective obtention of a fusion reaction, i.e., causing and capability to generate energy as claimed, as well as the benefits asserted by Applicants as of the effective date of the claims. Rather, the preponderance of evidence supports a finding that as of the effective date, the claimed system was at most at starting point for future investigation or research. See In re Swartz, 232 F.3d at 864, In re Cortright, 165 F.3d at 1357.
Claims 14–23 are further rejected under 35 U.S.C. 101 because the disclosed invention is inoperative and therefore lacks patentable utility for the reasons provided in the above 101 rejection, which are incorporated herein. Applicant alleges “a fast and cost-effective alternative for establishing a commercial fusion power plant” that produces net-output power, Specification at ¶ 3 and ¶ 40. In order for a self-sustaining nuclear fusion reactor to exist, breakeven/ignition must be achieved. As detailed above, no laboratory on Earth has yet achieved nuclear fusion ignition.
The Examiner has provided a preponderance of evidence as to why the asserted operation and utility of Applicant's invention is inconsistent with known scientific principles, making it speculative at best as to whether attributes of the invention necessary to impart the asserted utility are actually present in the invention. See In re Sichert, 566 F.2d 1154, 196 USPQ 209 (CCPA 1977). Accordingly, the invention as disclosed is deemed inoperable, i.e., it does not operate to produce the results claimed by the Applicant.
Applicant may overcome the rejections under 35 U.S.C. 101 and related 112(a) rejections by not claiming net power output or self-sustaining10 tritium production. Tritium production per se from a tokamak is considered a legitimate utility under 35 U.S.C. 101.
As set forth in MPEP § 2107.01(IV), a deficiency under 35 U.S.C. 101 also creates a deficiency under 35 U.S.C. 112, first paragraph. See In re Brana, 51 F.3d 1560, 34 USPQ2d 1436 (Fed. Cir. 1995). Citing In re Brana, the Federal Circuit noted,
“Obviously, if a claimed invention does not have utility, the Specification cannot enable one to use it.”
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 14–23 are rejected under U.S.C. 112(a). Specifically, because the claimed invention is not supported by a well-established utility or a substantial and credible asserted utility for the same reasons set forth in the rejections under 35 U.S.C. 101 (which are incorporated herein), one skilled in the art clearly would not know how to use the claimed invention.
Claims 14–23 are further rejected under U.S.C. 112(a) as failing to comply with the written description requirement. The claims contains subject matter which was not described in the Specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor at the time the application was filed, had possession of the claimed invention. Specifically, a person skilled in the art at the time the application was filed would not have recognized that the inventor was in possession of the invention as claimed in view of the disclosure for the reasons provided in the above 101 rejections, which are incorporated herein.
Claims 14–23 are rejected under 35 U.S.C. 112(a) because the best mode contemplated by the inventor(s) has not been disclosed. Evidence of concealment of the best mode is based upon the disclosure of the Tan (WO 2025/097586 A1) publication cited in the below 102 rejections. Tan discloses a fusion reactor that is allegedly self-sustaining, i.e., has achieved ignition, same as Applicant’s claimed invention. However, as shown in the above 101 and 112(a) rejections, no self-sustaining nuclear fusion reactor has ever been built. Accordingly, if Applicant's fusion apparatus is operable to achieve ignition, while Tan’s was not, then the Examiner must conclude that some essential information is missing from Applicant's disclosure that makes Applicant's invention operative.
Claims 14–23 are rejected under 35 U.S.C. 112(a) as failing to comply with the enablement requirement. The claims contains subject matter which was not described in the Specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
To be enabling, the disclosure, as filed, must be sufficiently complete to enable a person of ordinary skill in the art to make and a use the full scope of the claimed invention without undue experimentation. It is the Examiner’s position that an undue amount of experimentation would be required to produce an operative embodiment of the claimed invention.
Applicant admits that previous, well-funded and decades-long attempts at producing viable nuclear fusion reactors have been unsuccessful (Specification, ¶¶ 4–7). Even so, Applicant believes they have produced an operative system for achieving nuclear fusion for useful energy production, see Specification at ¶ 3 and ¶ 32.
To determine whether a given claim is supported in sufficient detail (by combining the information provided in the disclosure with information known in the art) such that any person skilled in the art could make and use the invention as of the filing date of the application without undue experimentation, at least the following factors should be included:
(A) The breadth of the claims;
(B) The nature of the invention;
(C) The state of the prior art;
(D) The level of one of ordinary skill;
(E) The level of predictability in the art;
(F) The amount of direction provided by the inventor;
(G) The existence of working examples; and
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure.
This standard is applied in accordance with the U.S. Federal Court of Appeals decision In re Wands, 858 F.2d at 731, 737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988). See also United States v. Telectronics Inc., 857 F.2d 778, 785, 8 USPQ2d 1217, 1223 (Fed. Cir. 1988), cert. denied, 490 U.S. 1046 (1989).
Reviewing the aforementioned Wands factors, the evidence weighs in favor of a finding that undue experimentation would be necessary to make and use the claimed invention, and therefore, a determination that the disclosure fails to satisfy the enablement requirement. Specifically:
(A) The breadth of the claims: Applicant’s claims to provide the world’s first-ever breakeven nuclear fusion reactor are inadequately detailed, e.g., clms. 18–20 simply recite the desired result of a net fusion energy gain, based on a simple tokamak, claims 14 and 17.
See MPEP § 2164.08.
(B) The nature of the invention: The nature of the invention, i.e., the subject matter to which the claimed invention pertains, revolves around the viability of nuclear fusion as a non-negligible source of useful energy; as such, the subject matter to which the invention pertains lies in the hitherto unsuccessful field of commercial nuclear fusion reactors.
(C) The state of the prior art: The effects claimed by Applicant have not been verified by the existing body of scientific work.
See MPEP § 2164.05(a).
(D) The level of one of ordinary skill: The level of ordinary skill in the art is a skilled artisan who understands net-negative magnetic and inertial confinement nuclear fusion reactors but who cannot yet build or operate one that would be considered useful, e.g., for electricity production, outside the realm of research.
See MPEP § 2164.05(b).
(E) The level of predictability in the art: Thermonuclear fusion devices have failed to make serious advances towards practical applications after more than half a century of research. The predicted successes are only predictable in that they require another decade or more of study.
See MPEP § 2164.03.
(F) The amount of direction provided by the inventor: Applicant’s claimed system utilizes an allegedly novel design that may be interesting, but no step-by-step guide is provided by Applicant to actually achieve the claimed end goal of self-sustained/breakeven nuclear fusion.
See MPEP § 2164.03.
(G) The existence of working examples: No working example is provided.
See MPEP § 2164.02.
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure: The quantity of experimentation needed is unreasonable because the practical guidance provided is insufficient to enable one to build or operate a working prototype of the invention, and the provided theoretical guidance is insufficient to enable one to understand the underlying sequence of phenomena required to attempt such an endeavor. See MPEP § 2164.06.
Any claim not specifically addressed in this section that depends from a rejected claim is also rejected under 35 U.S.C. 112(a), for its dependency upon an above–rejected claim and for the same reasons.
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 14–23 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 14–23 are rejected under 35 U.S.C. 112(b) as being incomplete for omitting essential elements, such omission amounting to a gap between the elements. See MPEP § 2172.01. The omitted elements are: the elements that make Applicant’s fusion apparatus operable to achieve ignition, while all those in the prior art (e.g., Tan, cited in the below 102 rejections, in addition to the previous efforts laid out in the above 112(a) and 101 rejections) are not operable to achieve ignition. This rejection is related to the above 112(a) best mode rejection. The Examiner can only conclude that if Applicant’s apparatus is operative, but Tan’s is not, then there must be omitted elements that are critical or essential to the invention.
Claim 16 is rejected because: a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) is considered indefinite, since the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). Note the explanation given by the Board of Patent Appeals and Interferences in Ex parte Wu, 10 USPQ2d 2031, 2033 (Bd. Pat. App. & Inter. 1989), as to where broad language is followed by "such as" and then narrow language. The Board stated that this can render a claim indefinite by raising a question or doubt as to whether the feature introduced by such language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required
feature of the claims. Note also, for example, the decisions of Ex parte Steigewald, 131
USPQ 74 (Bd. App. 1961); Ex parte Hall, 83 USPQ 38 (Bd. App. 1948); and Ex parte
Hasche, 86 USPQ 481 (Bd. App. 1949).
Per MPEP § 2173.05(c): Examples of claim language which have been held to
be indefinite include "a temperature of between 45 and 78 degrees Celsius, preferably
between 50 and 60 degrees Celsius". This is the type of language recited in claim 16, which recites the broad recitation “less than 100 MW” followed by the more narrow limitation “preferably less than 10 MW.” Thus, it is unclear if the claim recites an input power of less than 100 MW, or if it recites an input power of 10 MW or less, or something else. The metes and bounds of the claim cannot be determined.
The term “similar” in claim 14 is a relative term which renders the claim indefinite. The term “similar” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. There is no consensus in the art for what is possibly “similar” to an “inverse D-shape” versus what is “non-similar” to an ”inverse D-shape.” Therefore, the metes and bounds of the claim are unclear.
The limitation “optimized for plasma heating and current drive” in claim 16 is a relative limitation which renders the claim indefinite. The limitation is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. There is no consensus in the art for what is needed for the claimed optimization of “plasma heating and current drive.” Instead, this limitation reads like a method step that a reactor operator might perform. Therefore, the metes and bounds of the claim are unclear.
Any claim not specifically addressed in this section that depends from a rejected claim is also rejected under 35 U.S.C. 112(b), for its dependency upon an above–rejected claim and for the same reasons.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
For Applicant’s benefit, portions of the cited reference(s) have been cited to aid in the review of the rejection(s). While every attempt has been made to be thorough and consistent within the rejection, it is noted that the prior art must be considered in its entirety, including disclosures that teach away from the claims. See MPEP 2141.02 VI.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claims 14 and 15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Tan11 (WO 2025/097586 A1).
Regarding claim 14, Tan discloses (figs. 11-12) a compact spherical-type tokamak (30) comprising a toroidal vacuum vessel (vacuum chamber 301) and a magnetic field system (302, 303, 304, 305) configured to confine a high temperature plasma (within chamber 301), wherein: -the magnetic field system comprises: - a solenoid (302,305) having a sand-hourglass shape (as shown in Figs. 11-12, but also described as follows: “The first coil 302 may also be referred to as an ohmic coil or a central solenoid,” end of page 6, and “the fourth coil 305 can be a central solenoid,” page 10), - toroidal field coils (304) having an inverse D-shaped design and comprising high temperature superconductor (HTS) material (“The magnet including … the third coil 304 … can be made of a superconducting coil, which can achieve zero resistance at low temperatures,” mid-page 7), - poloidal field coils (303), external to the vacuum vessel wherein the vacuum vessel has a cross-section with similar inverse D-shape as the toroidal field coils (vacuum vessel 301 and toroidal coils 304 have a same or similar shape, see especially fig. 12).
Regarding claim 15, Tan anticipates all the elements of the parent claim, and further discloses a divertor (306) to reduce the heat and particle loads per unit area on the walls of the vacuum vessel (the embodiment of figs. 11-12 may also include a divertor 306, page 10 under the description of fig. 13).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
For Applicant’s benefit, portions of the cited reference(s) have been cited to aid in the review of the rejection(s). While every attempt has been made to be thorough and consistent within the rejection, it is noted that the prior art must be considered in its entirety, including disclosures that teach away from the claims. See MPEP 2141.02 VI.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 16, 17, 18, 19, 20, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Tan.
Regarding claim 16, Tan anticipates all the elements of the parent claim, and further discloses a neutral beam heating system (“The fusion fuel gas transmitted by the intake valve assembly can be hydrogen or deuterium,” page 11, second paragraph; “Step 406 … inject fusion fuel gas,” mid-page 12) with different injection angles (implicit per the tokamak design) optimized for plasma heating and current drive (this is an intended use clause that does not limit the apparatus claim; Tan’s apparatus may indeed be optimized per these basic parameters).
Tan discloses the invention except for he does not explicitly state delivering a power input to the plasma less than 100 MW, preferably less than 10 MW.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to have used an input power less than 100/10 MW, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In this particular case, the skilled artisan is clearly motivated to reduce the input energy required for the fusion reactor because more input electricity = more cost.
Regarding claim 17, Tan discloses a method of generating fusion energy by operating the compact spherical tokamak of claim 14 comprising the steps of: - inducing a plasma (“plasma,” abstract) current by the solenoid (see claim 14 rejection, above), - generating a magnetic field with a toroidal component (304) by the toroidal field coils (304), - confining the plasma in negative triangular shape (as shown in figs. 11-12, the inverse D-shape corresponds to a negative triangularity; also, “negative triangular deformation,” abstract) with an aspect ratio of 2.2 or less (the aspect ratio R/a in fig. 2 appears to be approximately 1.5), - operating a plasma current (“plasma,” abstract), [and] - emitting fusion alpha particles and neutrons and confining said alpha particles in the plasma (“The fusion fuel gas transmitted by the intake valve assembly can be hydrogen or deuterium,” page 11, second paragraph; Examiner notes that deuterium fusion emits neutrons and may also emit alphas).
Tan does not explicitly disclose the recited parameters of a major radius of 3 m or less, a ≤10T toroidal field and the plasma current being ≤14 MA.
Tan therefore discloses the invention except for he does not explicitly state using a major radius ≤3 m, a ≤10 T toroidal field, and the plasma current being ≤14 MA.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to have used a major radius ≤3 m, a ≤10 T toroidal field, and the plasma current being ≤14 MA, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In this particular case, the Examiner finds that none of the recited parameters lie outside what is typical in a tokamak fusion reactor, and therefore, the skilled artisan would not be surprised by the results of optimizing the major radius to ≤3 m, the toroidal field to ≤10 T, and the current to ≤ 14 MA. Furthermore, since fusion reactors are still a highly experimental field, the skilled artisan is extremely motivated to run both simulations and, where results seem promising, actual experiments based on dozens of optimizable and optimized basic parameters. Radius, magnetic field strength, and current are all basic parameters in any fusion reactor, as the skilled artisan would readily attest.
Regarding claim 18, Tan teaches all the elements of the parent claim, and further discloses a fusion energy gain factor Q>1 (“…achieving net energy output,” page 8, end of second paragraph) but does not explicitly disclose the amount of time the plasma is maintained.
Tan therefore discloses the invention except for he does not explicitly state maintaining the plasma in a steady state for more than 10 seconds. It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to have (at least attempted) to maintain the plasma in a steady state for ≥10 seconds, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In this particular case, the skilled artisan is clearly motivated to maintain the plasma in a steady state as long as possible. This is the entire focus of fusion research: maintaining the plasma long enough to effect a net-energy output.
Regarding claims 19-20, Tan teaches all the elements of the parent claim, and further discloses a fusion energy gain factor Q>1 (“…achieving net energy output,” page 8, end of second paragraph).
Tan therefore discloses the invention except for he does not explicitly state a fusion energy gain factor Q>10 or Q>50. It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to have (at least attempted) to effect a gain factor of Q>10 or Q>50, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In this particular case, the skilled artisan is clearly motivated to maximize the alleged net output fusion energy, as that is the entire purpose of an experiment attempting to produce a commercially viable reactor.
Regarding claim 21, Tan teaches all the elements of the parent claim, and further discloses wherein the step of generating further comprises generating a magnetic field with a toroidal component by the toroidal field coils (as cited above). Tan does not explicitly suggest optimizing the field strength to be less than 6 T.
Tan therefore discloses the invention except for he does not explicitly state optimizing the field strength to be less than 6 T.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to have used toroidal field strength < 6 T, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In this particular case, the skilled artisan is clearly motivated to reduce the input magnetic field energy required for the fusion reactor because more input = more cost.
Claims 22 and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Tan in view of Sykes (US 2013/0089171).
Regarding claims 22 and 23, Tan teaches all the elements of the parent claim, and further discloses generating neutrons at a rate by fusing deuterium (as cited above). Tan does not explicitly recite the (a) value of neutrons per second obtained or that (b) tritium may also be used as a fuel along with deuterium.
Regarding (a), it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to have (at least attempted) to effect a neutron output of 1x1017 or 5x1018 n/s, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In this particular case, the skilled artisan is clearly motivated to maximize the neutron output, as that is the entire purpose of an experiment attempting to produce a commercially viable reactor.
Regarding (b), Sykes does teach using tritium alongside deuterium as a fuel. Sykes is in the same art area of tokamaks and teaches adding tritium alongside deuterium (e.g., “The tokamak fuelling system is designed to inject the fuelling gas or solid pellets of hydrogen, deuterium, and tritium,” ¶ 83 and “50-50 D-T mix,” ¶ 86).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to have utilized a D-T mixture of 50-50 or 70-30, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. The skilled artisan is well-aware that D-D is typically cheaper and less problematic (Sykes, ¶ 20), but D-T is theoretically better (Sykes, ¶ 94). Therefore, the skilled artisan is motivated to incorporate tritium only as available/necessary. Furthermore, since fusion reactors are still a highly experimental field, the skilled artisan is extremely motivated to run both simulations and, where results seem promising, actual experiments based on dozens of optimizable and optimized basic parameters. Any fusion researcher knows that reactors may be generally D-D or D-T, and the relative ratios thereof are highly optimizable.
Conclusion
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LILY CRABTREE GARNER
Primary Examiner
Art Unit 3646
/LILY C GARNER/Primary Examiner, Art Unit 3646
1 “Fusion “ignition” refers to the moment when a controlled fusion reaction generates more energy than is needed to spark the reaction: as much or more energy “out” than “in.”” <lasers.llnl.gov/science/ignition>. Last accessed May 28, 2025.
2 All references to the Specification in this Action refer to the pre-grant publication.
3 How Long is the Fuse on Fusion? Springer Nature Switzerland AG 2020, pages 85–86.
4 What will ITER do? <iter.org/fusion-energy/what-will-iter-do>. Last accessed Sept 1, 2026.
5 Achieving Fusion Ignition. <lasers.llnl.gov/science/achieving-fusion-ignition>. Last accessed May 12, 2025.
6 Tollefson, Jeff, and Elizabeth Gibney. "Nuclear-fusion lab achieves ‘ignition’: What does it mean?." Nature 612.7941 (2022): 597-598.
7 Thomas, William. National Ignition Facility Achieves Long-Sought Fusion Goal. Dec 16 2022. AIP News article.
8 Temperatures for Fusion, Department of Physics and Astronomy, Georgia State University webpage: <hyperphysics.phy-astr.gsu.edu/hbase/NucEne/coubar.html>
9 See Specification at ¶¶ 8–11.
10 Not presently claimed.
11 See attached and Examiner-highlighted 42-page foreign reference.
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