DETAILED ACTION
This Office action is in response to the request for continued examination filed on March 30th, 2026. Claims 1-2, 5-11, and 21-31 are pending.
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 .
Claim Rejections - 35 USC § 103
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, 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.
Claim(s) 1-2 & 5-6 & 9-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 9,384,932 (the ‘932 patent) in view of US 3,508,058 (Frentrop) and the teachings of US 2022/0152982 (Knight et al.).
Regarding claim 1, the ‘932 patent discloses a method comprising:
brazing a welding ring to an insulating tube at a first open end to create a joining point for welding a target rod in place (‘Likewise, metal washer 284 is preferably brazed to the ceramic washer 267’ see also fig. 2);
disposing a target rod into the insulating tube, wherein the target rod is at least in part in contact with the welding ring (fig. 2, target rod 245, welding ring 282 in contact); and
joining the the target rod to the welding ring at the joining point to form a vacuum envelope (‘Likewise, metal washer 284 … is in (metal-to-metal) contact (e.g., welded) with the target 244.’).
The ‘932 patent does not disclose brazing a welding lip to the target rod, wherein the welding lip is configured abut the welding ring at the joining point and welding the welding lip to the welding ring at the joining point. Frentrop discloses a method of manufacturing a neutron generating tube including brazing a welding lip to the target rod (‘The sleeve 22 in turn is brazed to a target electrode 23 which is shaped to provide an end closure for the envelope.’). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to braze the welding lip of Frentrop to the target rod of the ‘932 patent and weld it to the welding ring to form the metal-to-metal contact between the welding ring and the target rod in the case that the metal used for the welding ring was too dissimilar from copper to form a direct weld between the welding ring and the target rod. Knight discloses that adding an insert between dissimilar metals too incompatible for direct welding is known method for forming metal-to-metal contacts (“Because traditional welding between aluminum and steel is not possible, a weld transition is inserted and welded between yoke 14 and anode bar 12.”).
The ‘932 patent also does not disclose disposing a copper tubing at a second open end of the insulating tube opposite the first open end; and pinching off the copper tubing to form a sealed vacuum in the insulating tube. Frentrop discloses disposing tubing at a second open end of the insulating tube opposite the first open end; and pinching off the tubing to form a sealed vacuum in the insulating tube (‘Cap 31 also serves as a header carrying a pinch-off tubulation 32’). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to modify the method of the ‘932 patent by adding and pinching the tubing so that the interior could be pumped down through the tube and then pinched off to seal. Frentrop does not specify whether the tubing is copper, but copper tubing is known in the art, and it would have been obvious to a person having ordinary skill in the art to use copper because of its high durability.
Regarding claim 2, the ‘932 patent in view of Frentrop and the teachings of Knight discloses the method of claim 1, wherein the target rod is copper (‘copper target’).
Regarding claim 5, the ‘932 patent in view of Frentrop and the teachings of Knight discloses the method of claim 1, further comprising disposing an ion source into the insulating tube (‘With a high voltage target, deuterium and/or tritium isotopes in the Minitron are ionized and accelerated into the target face to cause a fusion reaction that generates neutrons as a byproduct.’).
Regarding claim 6, the ‘932 patent in view of Frentrop and the teachings of Knight discloses the method of claim 1, wherein the ion source further comprises a hot cathode (“dispenser cathode”).
Regarding claim 9, the ‘932 patent in view of Frentrop and the teachings of Knight et al. discloses the claimed method except the ‘932 patent is silent as to whether a gas reservoir is disposed into the insulating tube. However, Frentrop discloses disposing such a gas reservoir (“The zirconium coating 88 responds to increases in filament temperature by emitting absorbed gas, and increasing the gas pressure in the envelope until an equilibrium pressure is reached. Conversely, decreases in filament temperature cause the zirconium to absorb gas from the tube atmosphere and thereby decrease the tube gas pressure.”) and the ‘932 patent discloses ionizing deuterium and/or tritium gas (“With a high voltage target, deuterium and/or tritium isotopes in the Minitron are ionized and accelerated into the target face to cause a fusion reaction that generates neutrons as a byproduct.”). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to dispose the gas reservoir of Frentrop into the tube of the ‘932 patent to provide a reservoir to hold the deuterium and/or tritium gas during pump down of the tube.
Regarding claim 10, the ‘932 patent in view of Frentrop and the teachings of Knight et al. discloses the method of claim 9, wherein the gas reservoir is Titanium or Zirconium (“The zirconium coating 88 responds to increases in filament temperature by emitting absorbed gas, and increasing the gas pressure in the envelope until an equilibrium pressure is reached. Conversely, decreases in filament temperature cause the zirconium to absorb gas from the tube atmosphere and thereby decrease the tube gas pressure.”).
Regarding claim 11, the ‘932 patent in view of Frentrop and the teachings of Knight et al. discloses the method of claim 10, wherein the gas reservoir stores deuterium and tritium (“With a high voltage target, deuterium and/or tritium isotopes in the Minitron are ionized and accelerated into the target face to cause a fusion reaction that generates neutrons as a byproduct.”).
Claim(s) 7-8 and 21-22 is/are rejected under 35 U.S.C. 103 as being unpatentable over the ‘932 patent in view of Frentrop and the teachings of Knight et al. as applied to claims 1, 5, and 9 above, and further in view of US 9,322,262 (Chirovsky et al.).
Regarding claim 7, the ‘932 patent in view of Frentrop and the teachings of Knight et al. discloses the claimed method except for disposing a grid between the ion source and the target rod. Chirovsky et al. disclose a method of assemblying a neutron generating tube including disposing a grid between the ion source and the target rod (“The cathode and grid are disposed in a sealed chamber.”, see element 44 in figures). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to modify the method of the ‘932 patent in view of Frentrop to include disposing of the grid of Chirovsky et al. because such a grid can extend the lifetime of the cathode, as discussed in Chirovsky et al. (“A pulsed neutron generator tube using a hot dispenser cathode wherein space charge limits are set in the ion generator using cathode to grid spacing and/or grid voltages as described herein may have longer cathode life than hot (dispenser) cathode-based pulsed neutron generator structures known in the art.”).
Regarding claim 8, the ‘932 patent in view of Frentrop, the teachings of Knight et al., and Chirovsky et al. disclose the method of claim 7, further comprising disposing an extractor electrode (an extractor electrode is inherent in the use of dispenser electrode, an extraction voltage required to draw out electrons) between the grid and the target rod, wherein the grid and the extractor electrode direct an ion beam transmitted from the ion source (Chirovsky et al., “An extractor 43 may be disposed proximate the longitudinal end of the ionizer 48.”).
Regarding claim 21, the ‘932 patent in view of Frentrop, the teachings of Knight et al., and Chirovsky et al. disclose the method of claim 7, wherein the grid is an electrode (“For purposes of defining the scope of the present disclosure, the term “grid” may be used to mean either an actual grid or an electrode; both may be considered to operate with equal effect as it concerns the present disclosure.”).
Regarding claim 22, the ‘932 patent in view of Frentrop, the teachings of Knight et al., and Chirovsky et al. disclose the method of claim 7, wherein the ion source generates an ion beam disposed within the sealed vacuum (‘With a high voltage target, deuterium and/or tritium isotopes in the Minitron are ionized and accelerated into the target face to cause a fusion reaction that generates neutrons as a byproduct.’).
Claim(s) 1-2, 5-11, and 21-31 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 2013/0256522 (the ’522 publication) in view of US 9,384,932 (the ‘932 patent), US 3,508,058 (Frentrop), and the teachings of US 2022/0152982 (Knight et al.).
Regarding claim 1, the ‘522 publication discloses a method of manufacturing a neutron generator comprising: affixing a welding ring to an insulating tube at a first open end to create a joining point for holding a target rod in place (‘The neutron generator 10 may include a hollow cylindrical tube 11 made of an insulating material such as alumina ceramic and having its respective longitudinal extremities fixed to a ceramic ring 12 and a conductive ring 13,’ P 15); disposing a target rod into an insulating tube at a first open end (fig. 1, target rod 15 is disposed into tube 11) and joining the welding ring to the target rod to form a vacuum envelope (‘A transverse header 14 and the target electrode 15 close the ceramic rings 12 and 13, respectively, to provide a gas-tight, hermetic cylindrical envelope.’).
The ‘522 publication does not disclose brazing the welding to the insulating tube, disclosing only that the two are affixed. The ‘522 publication also does not disclose brazing the welding lip to the target rod, wherein the welding lip is configured to abut with the welding ring at the joining point; and welding the welding lip to the welding ring, disclosing only that the ring and target rod are connected in a manner that forms a hermetic seal.
The ‘932 patent discloses a method of forming a neutron generating tube comprising brazing a welding ring to the insulating tube at a first open end to create a joining point for forming a metal-to-metal contact with the target (‘Likewise, metal washer 284 is preferably brazed to the ceramic washer 267’ see also fig. 2), and forming said metal-to-metal through welding (‘Likewise, metal washer 284 … is in (metal-to-metal) contact (e.g., welded) with the target 244.’). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to modify the method of the ‘522 publication to include the brazing and welding steps of the ‘932 patent to form the required sealing joints.
The ‘522 publication in view of the ‘932 patent still does not disclose brazing a welding lip to a target rod, wherein the welding lip is configured to abut the welding ring at the joining point; or welding being between such a lip and the welding ring. Frentrop discloses a method of manufacturing a neutron generator including brazing a lip to a target rod, the lip being used to attached the target rod to the neutron generating tube (‘The sleeve 22 in turn is brazed to a target electrode 23 which is shaped to provide an end closure for the envelope.’). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to braze the welding lip of Frentrop to the target rod of the ‘522 publication and weld it to the welding ring to form the metal-to-metal contact between the welding ring and the target rod in the case that the metal used for the welding ring was too dissimilar from copper to form a direct weld between the welding ring and the target rod. Knight discloses that adding an insert between dissimilar metals too incompatible for direct welding is known method for forming metal-to-metal contacts (“Because traditional welding between aluminum and steel is not possible, a weld transition is inserted and welded between yoke 14 and anode bar 12.”).
The ‘522 publication also does not disclose disposing a copper tubing at a second open end of the insulating tube opposite the first open end; and pinching off the copper tubing to form a sealed vacuum in the neutron generating tube. Frentrop discloses disposing tubing at a second open end of the insulating tube opposite the first open end; and pinching off the tubing to form a sealed vacuum in the insulating tube (‘Cap 31 also serves as a header carrying a pinch-off tubulation 32’). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to modify the method of the ‘522 publication by adding and pinching the tubing so that the interior could be pumped down through the tube and then pinched off to seal. Frentrop does not specify whether the tubing is copper, but copper tubing is known in the art, and it would have been obvious to a person having ordinary skill in the art to use copper because of its high durability.
Regarding claim 2, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 1, wherein the target rod is copper (‘copper target electrode 15’ P 15).
Regarding claim 5, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 1, further comprising disposing an ion source into the insulating tube (‘A gas ionizer is also disposed in the sealed tube.’ P 8).
Regarding claim 6, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 5, wherein the ion source further comprises a hot cathode (‘The cathode 80 may include an electron emitter 81 comprising a block of material susceptible, when heated, to emit electrons.’).
Regarding claim 7, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 5, further comprising disposing a grid between the ion source and the target rod (fig. 1, element 95).
Regarding claim 8, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 7, further comprising disposing an extractor electrode between the grid and the target rod, wherein the grid and the extractor electrode direct an ion beam transmitted from the ion source (fig. 1, element 50).
Regarding claim 9, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 1, further comprising disposing a gas reservoir into the insulating tube (fig. 1, element 25).
Regarding claim 10, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 9, wherein the gas reservoir is Titanium or Zirconium (‘the gas reservoir 25, being a combination of the filament 26 and getter 44 … The getter 44 may be made from a sintered, porous material having therein interspersed particles of titanium and molybdenum.” P 26-27).
Regarding claim 11, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 10, wherein the gas reservoir stores deuterium and tritium (‘porous getter having deuterium and/or tritium adsorbed’ P 9).
Regarding claim 21, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 7, wherein the grid is an electrode (fig. 1, element 95).
Regarding claim 22, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the method of claim 7, wherein the ion source generates an ion beam disposed within the sealed vacuum (‘The ionized gas is accelerated to strike a target in the sealed envelope.’ P 9).
Regarding claim 23, the ‘522 publication discloses a system comprising: a welding ring (fig. 1, element 13) affixed to an insulating tube with a first open end (fig. 1, element 11) to create a joining point for connecting a target rod in place; a target rod, wherein the target rod is disposed into the insulating tube (fig. 1, element 15), wherein the welding ring and insulating tube are joined to form a vacuum envelope (‘The neutron generator 10 may include a hollow cylindrical tube 11 made of an insulating material such as alumina ceramic and having its respective longitudinal extremities fixed to a ceramic ring 12 and a conductive ring 13, … to provide a gas-tight, hermetic cylindrical envelope.’ P 15).
The ‘522 publication does not specify that the welding ring is brazed to the insulating tube, simply stating that they are affixed without specifying the means. The ‘932 patent discloses a neutron generating system where the conductive welding ring is brazed to the insulating tube (“According to a further embodiment of the invention, each end of annular ceramic element is coupled to a metal washer which contacts a respective electrode. The hermetic metal to ceramic coupling may be accomplished by brazing with a material such as KOVAR (a trademark of Carpenter Technology Corporation) or by other techniques known in the art.”). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to braze the conductive ring of the ‘522 publication to the insulating tube as done in the ‘932 patent because this forms a hermetic seal, as disclosed in the ‘932 patent quote above.
The ‘522 publication further does not disclose a welding lip brazed to the target rod and abutting and welded to the welding ring. Frentrop discloses a neutron generating system including a welding lip brazed to the target rod (‘The sleeve 22 in turn is brazed to a target electrode 23 which is shaped to provide an end closure for the envelope.’). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to braze the welding lip of Frentrop to the target rod of the ‘522 publication and weld it to the welding ring to form the metal-to-metal contact between the welding ring and the target rod in the case that the metal used for the welding ring was too dissimilar from copper to form a direct weld between the welding ring and the target rod. Knight discloses that adding an insert between dissimilar metals too incompatible for direct welding is known method for forming metal-to-metal contacts (“Because traditional welding between aluminum and steel is not possible, a weld transition is inserted and welded between yoke 14 and anode bar 12.”).
Finally, the ‘522 publication does not disclose a copper tubing disposed at a second end of the insulating tube opposite of the first open end, wherein a sealed vacuum is formed in the insulating tube by pinching off the copper tubing. Frentrop discloses such tubing (‘Cap 31 also serves as a header carrying a pinch-off tubulation 32’). It would have been obvious to a person having ordinary skill in the art at the time the application was filed to add such a tubing to the system of Perkins et al. tubing to provide a gas connection for evacuation, which is disclosed by Perkins et al. though it does not specify how it is done. It would further have been obvious to pinch the tubing as in Frentrop to seal after pumping. Frentrop does not specify whether the tubing is copper, but copper tubing is known in the art, and it would have been obvious to a person having ordinary skill in the art to use copper because of its high durability.
Regarding claim 24, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the system of claim 24, wherein the target rod is copper (“a copper target electrode 15.” P 15).
Regarding claim 25, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the system of claim 24, further comprising an ion source disposed in the insulating generating tube (fig. 1, element 45).
Regarding claim 26, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the system of claim 25, wherein the ion source further comprises a hot cathode (fig. 1, element 81).
Regarding claim 27, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the system of claim 25, further comprising a grid disposed between the ion source and the target rod (fig. 1, element 95).
Regarding claim 28, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the system of claim 27, further comprising an extractor electrode disposed between the grid and the target rod, wherein the grid and the extractor electrode direct an ion beam transmitted from the ion source (fig. 1, element 50).
Regarding claim 29, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the system of claim 23, further comprising a gas reservoir disposed in the insulating tube (fig. 1, element 25).
Regarding claim 30, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the system of claim 29, wherein the gas reservoir is Titanium or Zirconium (‘the gas reservoir 25, being a combination of the filament 26 and getter 44 … The getter 44 may be made from a sintered, porous material having therein interspersed particles of titanium and molybdenum.” P 26-27).
Regarding claim 31, the ‘522 publication in view of the ‘932 patent, Frentrop, and the teachings of Knight et al. discloses the system of claim 30, wherein the gas reservoir stores deuterium and tritium (‘porous getter having deuterium and/or tritium adsorbed’ P 9).
Response to Arguments
Applicant's arguments filed March 30th, 2026 have been fully considered but they are not persuasive.
Applicant argues that Frentrop merely discloses that the metal sleeve is brazed to the target electrode and cannot be reasonably construed to teach brazing a welding ring to the insulating tube or welding the metal lip to a welding ring.
Examiner does not rely on Frentrop to teach either brazing a welding ring to the insulating tube or to welding the metal lip to a welding ring. Examiner relies on Frentrop only to teach brazing a metal lip to a target rod and for the copper tubing. Perkins discloses both brazing of the welding ring and welding metal-to-metal contacts, so Frentrop does not need to teach or suggest those features.
Applicant notes that construction of neutron generating tubes is complex and difficult and that their embodiments present techniques to mitigate these difficulties and manufacture neutron generating tubes that are more robust and have other benefits.
This argument fails to comply with 37 CFR 1.111(b) because it amounts to a general allegation that described embodiments constitute a patentable invention without specifically pointing out how the language of the claims patentably distinguishes them from the references.
Conclusion
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/ELIZA W OSENBAUGH-STEWART/Primary Examiner, Art Unit 2881
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