US2665392A - Magnetic induction accelerator - Google Patents
Magnetic induction accelerator Download PDFInfo
- Publication number
- US2665392A US2665392A US192733A US19273350A US2665392A US 2665392 A US2665392 A US 2665392A US 192733 A US192733 A US 192733A US 19273350 A US19273350 A US 19273350A US 2665392 A US2665392 A US 2665392A
- Authority
- US
- United States
- Prior art keywords
- field
- guiding field
- guiding
- acceleration
- magnetic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
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Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H11/00—Magnetic induction accelerators, e.g. betatrons
- H05H11/02—Air-cored betatrons
Definitions
- This invention relates to a magnetic induction accelerator for electrically charged elementary particles, e. g., electrons, and is particularly con-- cerned. with an accelerator for therapeutic irradiation.
- magnetic induction accelerator refers to a device in which elementary particles, e. g., electrons, are moved. along approximately circular paths in a magnetic. guiding field and.
- One. of the principalobjects of the invention is to reduce the weight of the magnetic iron in an accelerator of the above-noted type so as to obtain appreciable reduction of its total weight and bulk for the purpose of adapting it for use as a radiation source in therapeutic irradiation apparatus.
- the guiding field poles are so dimensioned that the guiding field; strength increases, as usual, in the neighborhood of the equilibrium orbit up to the final acceleration of the electrons in proportion with the accelerating field while magnetic saturation occurs therein at an intensity or strength of the acceleration which is relatively small compared with its final intensity.
- the invention is based on recognition of the fact that the electrons fill the evacuated acceleration tubeor chamber in the form of a broad band only at the commencement of acceleration, and concentrate quickly toward the equilibrium orbit, oscillating finally about said orbit within a radially narrow zone.
- the guiding field therefore has to be as wide as the evacuated tube only at the start of acceleration, so as to secure all electrons in their orbital equilibrium paths.
- the width of the guiding field may diminish with the narrowing of the electron bundle. In other words only in a portion of the guiding field which is present at the start of acceleration need the field strength increase corresponding to the 1 2 condition up to the final acceleration along the equilibrium orbit.
- the magnetic iron of the guiding field poles outside of the region near the equilibrium orbit and also the yoke may therefore be generally of smaller Weight and dimensions than heretofore.
- the toroidal accelerating tube or chamber 9 is disposed between the opposite guiding field poles 5, 6 and provides therein a closed orbital path along which the electrons are accelerated.
- guiding field poles 5, 6 form an inner guiding field zone which embraces the equilibrium paths of the electron particles with-in the tube 9 and are provided with generally ring-shaped magnetic pole shoes 10, H which are integral therewith and extend generally radially outwardly therefrom, forming an outer guiding field zone.
- the pole shoes 10, I I are about as wide as the guiding field poles 5, and somewhat wider than the tube 9. These shoes are so dimensioned that their saturation begins at the most at such time when the excitation caused by the coils l2, 13 has reached about tenfold value of the excitation at the injection of the electrons. From this moment on, the guiding field flux increases in accordance with the 1:2 condition only in the poles 5, 6 and not any more in the shoes extending therefrom.
- the field strength in said inner guiding field zone controlled by the poles 5, 6 increases substantially proportional with the field strength of the acceleration field
- the ring-shaped pole shoes 10, H become magnetically saturated at a field strength of the acceleration field which is small as compared with the final field strength thereof to cause further increase of the field strength in said outer guiding field zone which is less than proportional with the further increase of the field strength in said acceleration field. Accordingly, the total flux in the yoke does not increase to an extent as would be the case if the 1 2 condition were maintained for the entire guiding field.
- a magnetic induction accelerator for electrically charged particles comprising an annular tube providing therein a closed orbital path along which the particles are accelerated, a magnetic yoke, accelerating pole pieces magnetically cou pled to said yoke forming a path for the magnetic flux of the acceleration field which extends centrally of said tube, magnetic guiding field poles projecting generally radially outwardly from said acceleration pole pieces forming outside of said tube on opposite sides thereof annular opposing inner surfaces defining an inner guiding field zone which embraces the equilibrium paths of said particles within said tube, and generally annularly extending magnetic pole shoes projecting generally radially outwardly from said guiding field poles forming outside of said tube on opposite sides thereof annular axially opposing inner surfaces defining an outer guiding field zone.
- acceleration pole pieces and the guiding field poles and said ring-shaped pole shoes are formed by common integral members, each member having slots to separate the accelerating pole piece from the guiding field poles thereof.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Particle Accelerators (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE284202X | 1949-10-31 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2665392A true US2665392A (en) | 1954-01-05 |
Family
ID=6050588
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US192733A Expired - Lifetime US2665392A (en) | 1949-10-31 | 1950-10-28 | Magnetic induction accelerator |
Country Status (4)
Country | Link |
---|---|
US (1) | US2665392A (ja) |
CH (1) | CH284202A (ja) |
GB (1) | GB688940A (ja) |
NL (1) | NL90802C (ja) |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2193602A (en) * | 1938-05-06 | 1940-03-12 | Westinghouse Electric & Mfg Co | Device for accelerating electrons to very high velocities |
US2484549A (en) * | 1947-07-30 | 1949-10-11 | Gen Electric | Electron injection apparatus |
US2491345A (en) * | 1946-08-07 | 1949-12-13 | Gen Electric | Accelerator magnet structure |
US2510448A (en) * | 1944-10-04 | 1950-06-06 | Bbc Brown Boveri & Cie | Magnetic induction accelerator |
US2585549A (en) * | 1949-11-02 | 1952-02-12 | Bbc Brown Boveri & Cie | Apparatus for accelerating electrons |
US2624020A (en) * | 1949-12-01 | 1952-12-30 | Bbc Brown Boveri & Cie | Apparatus for accelerating electrically charged particles |
-
0
- NL NL90802D patent/NL90802C/xx active
-
1950
- 1950-09-26 CH CH284202D patent/CH284202A/de unknown
- 1950-10-28 US US192733A patent/US2665392A/en not_active Expired - Lifetime
- 1950-10-30 GB GB26457/50A patent/GB688940A/en not_active Expired
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2193602A (en) * | 1938-05-06 | 1940-03-12 | Westinghouse Electric & Mfg Co | Device for accelerating electrons to very high velocities |
US2510448A (en) * | 1944-10-04 | 1950-06-06 | Bbc Brown Boveri & Cie | Magnetic induction accelerator |
US2491345A (en) * | 1946-08-07 | 1949-12-13 | Gen Electric | Accelerator magnet structure |
US2484549A (en) * | 1947-07-30 | 1949-10-11 | Gen Electric | Electron injection apparatus |
US2585549A (en) * | 1949-11-02 | 1952-02-12 | Bbc Brown Boveri & Cie | Apparatus for accelerating electrons |
US2624020A (en) * | 1949-12-01 | 1952-12-30 | Bbc Brown Boveri & Cie | Apparatus for accelerating electrically charged particles |
Also Published As
Publication number | Publication date |
---|---|
GB688940A (en) | 1953-03-18 |
NL90802C (ja) | |
CH284202A (de) | 1952-07-15 |
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