US3699381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion source device having control means for reducing filament current below its starting value
Assignee: Hitachi Ltd
•
Filing: 1971-01-11
•
Granted: 1972-10-17
•
Expires: 1991-01-11
Abstract
Abstract An ion source device of the Duoplasmatron type has a current reduction resistor in the filament circuit thereof for reducing the filament current during steady state operation thereof, and a relay adapted to normally short-circuit both terminals of the current reduction resistor, which relay is energized by a current flowing through an intermediate electrode circuit so as to open both of these terminals of the resistor thereby making it possible to reduce the steady state filament current.
Inventors
- 👤 Toshio Kondo
- 👤 Hifumi Tamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:42
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/022; H01J27/00; H01J27/02; H01J27/08; H01J27/10; H01J37/00; H01J37/02; H01J37/04; H01J37/08; H01J37/24; H01J37/242; Y; Y10; Y10S; Y10S315/00; Y10S315/05
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
169 words
In an ion source device for an ion micro-analyzer and the like comprising a filament for emitting electrons, an intermediate electrode for accelerating said electrons emitted from said filament, a heating power source connected in circuit to said filament for supplying a filament current to said filament at a starting value necessary to initiate a gaseous discharge in the space adjacent said intermediate electrode, a first voltage source connected between said filament and said intermediate electrode, anode means for accelerating ions produced in the space adjacent said intermediate electrode, a magnet disposed between said intermediate electrode and said anode for concentrating said ions, and an extractor of said ions and a second voltage source connected between said extractor and said anode, the improvement which comprises filament current control means responsive to a discharge current flowing from said first voltage sOurce to said intermediate electrode for reducing and maintaining said filament current at a lesser value than said starting value, which lesser value is still sufficient to maintain said discharge.
Claim 2
Dependent Claim
169 words
In an ion source device for an ion micro-analyzer and the like comprising a filament for emitting electrons, an intermediate electrode for accelerating said electrons emitted from said filament, a heating power source connected in circuit to said filament for supplying a filament current to said filament at a starting value necessary to initiate a gaseous discharge in the space adjacent said intermediate electrode, a first voltage source connected between said filament and said intermediate electrode, anode means for accelerating ions produced in the space adjacent said intermediate electrode, a magnet disposed between said intermediate electrode and said anode for concentrating said ions, and an extractor of said ions and a second voltage source connected between said extractor and said anode, the improvement which comprises filament current control means responsive to a discharge current flowing from said first voltage sOurce to said intermediate electrode for reducing and maintaining said filament current at a lesser value than said starting value, which lesser value is still sufficient to maintain said discharge.
Claim 3
Dependent Claim
32 words
The combination defined in claim 1, wherein said filament current control means includes switching means for selectively increasing the resistance of said filament circuit in response to detection of said discharge current.
Claim 4
Dependent Claim
28 words
The combination defined in claim 1, wherein said magnet is made of an electrical insulating material and is disposed in contact with said intermediate electrode and said anode.
Claim 5
Dependent Claim
62 words
The combination defined in claim 1, wherein said filament current control means includes a current reduction resistor connected in series between said filament and said heating power source, and switching means normally short-circuiting said current reduction resistor for removing said short-circuit in response to said discharge current, so as to reduce said filament current in the steady operating state of said device.
Claim 6
Dependent Claim
47 words
The combination defined in claim 4, wherein said switching means includes a movable switch contact normally connected across said current reduction resistor and an operating winding connected between said first voltage source and said intermediate electrode for actuating said movable switch contact when energized by current flow.
Claim 7
Dependent Claim
28 words
The combination defined in claim 5, wherein said magnet is made of an electrical insulating material and is disposed in contact with said intermediate electrode and said anode.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |