http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-3786258-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_c7b87237907dcb9c5f85cf62489916c0 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G21K1-02 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H05H3-06 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G21K1-02 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H05H3-06 |
| filingDate | 1972-02-01-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| grantDate | 1974-01-15-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_6236b7fdcf6c019883cb7c75fa21e5a5 |
| publicationDate | 1974-01-15-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | US-3786258-A |
| titleOfInvention | Closed system neutron generator tube |
| abstract | A closed system, sealed-off neutron generator tube is described which generates 14 MeV neutrons from the T(d,n)He4 nuclear reaction on a deuterium and tritium absorption loaded target surface onto which accelerated deuterium and tritium gas ions are impinging. The electrode structure of the tube consists of a magnetic poleface of one polarity, a cathode electrode in front of and adjacent to, but electrically insulated from that poleface and, a non-magnetic metallic anode discharge chamber surrounding the cathode electrode in vacuum tight connection with the first magnetic poleface which chamber ends in a full-width opened emission aperture, the rim of which constitutes another magnetic poleface. An acceleration electrode aperture whose cross-section corresponds and is adjacent to the emission aperture constitutes a short and wide acceleration gap. A target electrode opposite to the cathode electrode beyond the acceleration gap is electrically connected to the acceleration electrode and its surface is prepared with a tritium and deuterium absorbed target sheath. A magnetic field of about 1,000 - 2,000 Oe is applied by outside current windings. The path of the magnetic field emerges from the poleface behind the cathode electrode, intersects the latter, spreads along the anode discharge chamber and declines laterally in the region of the emission aperture so as to enter the poleface at its rim. A magnetic yoke outside of the windings serves to close the magnetic path between the polefaces of either polarity. The target and acceleration electrode potential is maintained at about 100 - 300 kV, while the potential of the cathode electrode is maintained at about 10 - 30 kV, both potentials being applied with a negative polarity with respect to the anode discharge chamber by means of appropriate feed-through insulators. Forced water flow cooling is provided for the electrodes, part of the vacuum envelope and the magnetic coils. Positive ions are generated inside the anode discharge chamber by means of a self-sustained low pressure high-voltage cold cathode discharge with the ionizing electrons trapped in a region of crossed magnetic and electric fields. An electron cloud rotating differentially and of nearly uniform density thus ionizes the low pressure tritium deuterium gas mixture. The ions discharged from this region by the electric discharge field are either lost to the cathode electrode or to a larger degree driven in the opposite direction into the region of the wide emission aperture and enter the continuing electric field of the acceleration gap upon passing the acceleration electrode aperture, these ions obtain a sufficient velocity to release neutrons from the fusion reactions when they finally impinge on the target surface material. Secondary electrons, released from the target surface by the impinging ions and accelerated in the opposite direction to the ion flow, pass the acceleration gap and the discharge region and must be intercepted by the cathode electrode. High flux neutron irradiation of samples for activation analysis or production of short-lived radioisotopes is achieved inside a cylindrical target. In this geometry, a fairly uniform neutron flux distribution is produced by bombarding the cylindrical target at its outside with ions generated in an annular discharge region concentric to the target, whicH ions are accelerated radially inward onto the target. The axially measured width of the ion current density distribution should be comparable to the diameter of the target cylinder. A well collimated neutron beam, with a high dose rate applicable in medical cancer therapy irradiation with fast neutrons, is produced in the axial direction to the target cylinder outside of a thick radiation shield which is equipped with a collimating bore with the cross-section corresponding to that of the target cylinder. Optimum collimation is obtained by a slightly conical target cylinder having the form of a truncated cone with its apex located half-way on the axis along the collimating bore. An inside shielding cone resembling the residual of the target frustrum up to the apex tip is inserted into the first half of the collimating bore. The latter may be interchangable, thus being either divergent, cylindrical or convergent, depending on the size of the irradiation field to be actually used. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2010169134-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-9177749-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-5949835-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-8822912-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-8374306-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-5745536-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-8153997-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/WO-9406122-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2009196390-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-8779351-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/WO-8505727-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4139777-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-7342988-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2007237281-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-8666015-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-9389334-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4008411-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2006017411-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6036631-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-8644442-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4997619-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2007197497-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2008080659-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4529571-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6925137-B1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2010282978-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-114340132-B http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-114340132-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2003234355-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6577697-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2014210340-A1 |
| priorityDate | 1971-03-13-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 64.