EP3238225B1 - Source d'electrons de haute energie a base de cnt avec element de commande par onde electromagnetique deportee - Google Patents
Source d'electrons de haute energie a base de cnt avec element de commande par onde electromagnetique deportee Download PDFInfo
- Publication number
- EP3238225B1 EP3238225B1 EP15820149.1A EP15820149A EP3238225B1 EP 3238225 B1 EP3238225 B1 EP 3238225B1 EP 15820149 A EP15820149 A EP 15820149A EP 3238225 B1 EP3238225 B1 EP 3238225B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- source
- scco
- electrode
- electron source
- field effect
- 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.)
- Active
Links
- 238000012216 screening Methods 0.000 claims description 51
- 239000002071 nanotube Substances 0.000 claims description 46
- 239000000758 substrate Substances 0.000 claims description 27
- 230000005669 field effect Effects 0.000 claims description 26
- 230000003287 optical effect Effects 0.000 claims description 17
- 238000005538 encapsulation Methods 0.000 claims description 9
- 239000012212 insulator Substances 0.000 claims description 9
- 208000036822 Small cell carcinoma of the ovary Diseases 0.000 claims description 8
- 201000005292 ovarian small cell carcinoma Diseases 0.000 claims description 8
- 230000005684 electric field Effects 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 5
- 239000013307 optical fiber Substances 0.000 claims description 5
- 239000011343 solid material Substances 0.000 claims description 2
- 229910052799 carbon Inorganic materials 0.000 claims 1
- 230000001939 inductive effect Effects 0.000 claims 1
- 239000002121 nanofiber Substances 0.000 claims 1
- 239000002041 carbon nanotube Substances 0.000 description 25
- 230000005540 biological transmission Effects 0.000 description 7
- 230000004907 flux Effects 0.000 description 7
- 238000005286 illumination Methods 0.000 description 6
- 239000002134 carbon nanofiber Substances 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 5
- 230000010354 integration Effects 0.000 description 5
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical class C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 5
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 4
- 229910021393 carbon nanotube Inorganic materials 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- 238000002955 isolation Methods 0.000 description 3
- 239000000615 nonconductor Substances 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 235000021183 entrée Nutrition 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 239000011787 zinc oxide Substances 0.000 description 2
- 229920000297 Rayon Polymers 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000010719 annulation reaction Methods 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002118 epoxides Chemical class 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002048 multi walled nanotube Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000002964 rayon Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/30—Cold cathodes, e.g. field-emissive cathode
- H01J1/304—Field-emissive cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J35/00—X-ray tubes
- H01J35/02—Details
- H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
- H01J35/06—Cathodes
- H01J35/065—Field emission, photo emission or secondary emission cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2235/00—X-ray tubes
- H01J2235/06—Cathode assembly
- H01J2235/062—Cold cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2235/00—X-ray tubes
- H01J2235/06—Cathode assembly
- H01J2235/068—Multi-cathode assembly
Definitions
- the invention relates to a high energy electron source, between 20 and 500 kV, for example, comprising at least one switchable or modulatable cathode or electron source and an electromagnetic wave control element external to the cathode structure. switchable.
- It is used in the field of electron tubes incorporating an electron gun, and more particularly in the field of X-ray tubes. It relates to switchable or modulatable cathodes comprising one or more field effect emitters, or based on nanotubes. carbon nanofibers or CNT, associated with an electromagnetic wave (SCCO) controlled current source that can be physically deported out of the X-ray tube. It relates to an X-ray source, RX, delivering a wave-controlled RX flux. electromagnetic, for example an optical illumination source, and can be switched between an ON state and an OFF state or be regulated between these two states.
- SCCO electromagnetic wave
- Switchable cathodes with an electromagnetic wave proposed today are optically controlled cathodes (photocathodes).
- CNT photocathodes One of the problems in CNT photocathodes is that photoelements physically associated with CNTs are subject to X-rays and ionizing bombardment within the tube enclosure. Their integration therefore requires a hardening technology.
- their integration in the form of a network homologous to the network of CNTs constrains the possible dimensions of these photoelements, which can limit their breakdown voltage, for example typically 40V, while the use of larger photoelements allows voltages of breakdown up to several hundred volts.
- the document US 2006/0002514 discloses a device comprising an array of electronic transmitters associated with an extraction grid, a photosensitive component connected to a voltage source and to the extraction grid, and to a resistor connected to the mass.
- the gate is positively polarized with respect to the tip so as to allow the emission of electrons from this tip.
- the emission of electronic transmitters depends on the difference in voltage between the gate voltage and the tip voltage. This voltage difference depends on the on or off state of the photosensitive device.
- the emission current then follows the Fowler-Nordheim law known to those skilled in the art which is, as a first approximation, an exponential of the gate voltage. As a result, the emission current can not be finely controlled.
- the patent US 5,804,833 discloses a structure comprising a photocathode and an anode.
- the photocathode comprises an emitter structure made on a detector structure.
- the bias voltage is typically 10 kV.
- Such a configuration does not make it possible to manufacture an RX source (operating voltage of 50 to 500 kV) having a low RX flux in the OFF state corresponding to the unlit detector structure.
- This patent discloses a second configuration that involves the use of a voltage source to bias the gate relative to the contact to activate the sensing structure.
- the addition of a source of voltage at the photocathode complicates the high voltage supply of the photocathode, by adding a photocathode transformer. isolation, for example.
- the detector and emitter structures are made in a continuous piece of semiconductor with the photoconductive element located under the emitter. It is therefore exposed to X-rays generated in the tube.
- the photoelements always having a leakage current, there is an electron emission current that generates on the target X-rays. These X-rays in turn generate a current in the photoconductor. This loop induces the appearance of a residual flow of X-rays. It is therefore not possible in this configuration to obtain an extremely low residual X-ray flux in the OFF state, ie, without illumination of the photoelement.
- the subject of the invention relates to a new high energy electron source structure controllable by an electromagnetic wave based on field effect transmitters, for example carbon nanotubes / nanofibers (CNT) where the configuration of the electrodes of the switchable cathode allows a dynamic reconfiguration of the potential in the vicinity of the CNTs.
- CNT carbon nanotubes / nanofibers
- the nanotube or nanotubes are electrically connected to a base, all placed on a surface.
- the reconfiguration of the potential is in particular ensured by the coupling of the CNTs with a current source controlled by an electromagnetic wave (SCCO) which is externalised from the substrate and which, in fact, can be physically removed from a tube incorporating the switchable cathode (or modular) as an electronic source.
- SCCO electromagnetic wave
- This integration makes it possible in particular to avoid the direct exposure of the photoelement to the X-rays generated in the tube and the effect of the high-energy ion flux on the cathode which may lead to erosion or a modification of the electrical properties of the substrate, for example , the hydrogenation of silicon.
- the SCCO is disposed in a high voltage connector associated with the vacuum chamber, said connector comprising a window transparent to the electromagnetic wave, at least one source of electromagnetic waves controlled by the control circuit.
- the source of electromagnetic waves is an optical source such as a laser source, a laser diode, a light emitting diode, and the window is transparent to the wavelength of the optical source.
- the source of electromagnetic waves is a radiofrequency source comprising a transmission module and an RF radiofrequency transmission antenna
- the SCCO comprises an RF reception antenna connected to an RF reception module, and a source current controlled by this receiving module.
- the SCCO includes, for example, an RF receiving antenna connected to an RF receiving module, two cathodes and a microprocessor adapted to drive the current generation.
- a switchable or modulatable cathode based on field effect transmitters comprises at least two zones, each of these zones is connected to an output of a corresponding current source and one or more connected laser sources. to a control circuit.
- the transport of the optical wave can be carried out using an insulating optical fiber inserted into a solid material.
- the substrate comprises a screening electrode having on one part an opening Oi, on which an encapsulation insulator is deposited, the base electrode and the emitter being arranged opposite the the opening made in the screening electrode.
- a base electrode having a radius R the distance between the base electrode and the screening electrode is of the order of R.
- the electron source may comprise a substrate covered with an insulating layer comprising a via allowing contact of the base electrode of the field effect transistor, a screening electrode positioned around a transmitter effect of field, a layer of encapsulation insulator deposited to cover the screening electrode and at least partially the base electrode of the nanotube.
- the source may also include an array of field effect transmitters connected to the substrate through the presence of through contacts.
- the substrate comprises a continuous screening electrode, an encapsulation insulator on which are positioned the base electrode and the associated field effect transmitter.
- a field effect transmitter is a carbon nanotube or a carbon nanofiber.
- the invention also relates to a source of electrons where the electrons strike an anode for the production of X-rays.
- CNTs CNTs
- micrometric field effect transmitter for example, silicon or metal micropoints, diamond, zinc oxide ZnO, etc.
- the figure 1 discloses a first exemplary embodiment of a switchable or modulatable electromagnetic wave high energy electron source 100 which comprises a grounded vacuum enclosure 101 including an X-ray transparent window 102, a high voltage power supply 103, ( -30 to -500 kV), a switchable cathode 104 based on field effect emitters, for example carbon nanotubes / nanofibers CNT 105, integrating one or more screening electrodes 111, the conductive layers on the other hand, else or around the nanotube are connected.
- a switchable or modulatable electromagnetic wave high energy electron source 100 which comprises a grounded vacuum enclosure 101 including an X-ray transparent window 102, a high voltage power supply 103, ( -30 to -500 kV), a switchable cathode 104 based on field effect emitters, for example carbon nanotubes / nanofibers CNT 105, integrating one or more screening electrodes 111, the conductive layers on the other hand, else or around the nanotube are connected.
- the electromagnetic wave current control element is arranged outside the vacuum chamber, the switchable cathode and the SCCO being polarized at the high negative voltage, an anode 106 at ground, a wave source electromagnetic 107, for example an optical source such as a laser, a laser diode or a light emitting diode, a window transparent to the electromagnetic wave 108 and a control circuit 109 of this source of electromagnetic waves, for example an optical source .
- the supply of the source is galvanically decoupled from the high voltage supply 103.
- the high voltage supply 103 delivers a potential having a value chosen to create an anode field sufficient to induce transmission from the transmitter 105.
- the current control element (SCCO) remote from the enclosure in this example, is a phototransistor or photodiode illuminated by an optical source through an optically transparent window and a gas optically transparent dielectric.
- the SCCO 120 is located in a high voltage connector 121, comprising a ground-tight envelope 122 and composed of electrical insulators 123 and pressurized gas with high dielectric strength and optically transparent 124.
- the switchable cathode 104 ( figure 2 , figure 3 ) comprises at least one multi-wall carbon nanotube / nanofiber 105 (CNT), comprising a conductive surface 105s located under the foot of the emitter, the CNT is oriented vertically relative to the plane of the cathode, a screening electrode 111 of the field induced by the anode 106 located on either side or around the nanotube, these elements being arranged on a substrate 112.
- the electrical insulator 115 has openings at the base electrodes 110 so as to connect electrically the CNTs 105 to the substrate 112.
- a CNT has an important aspect ratio, for example, in the range [100-200], between its length one hundred nanometers to several microns, and its diameter taken at the apex or equivalent for apex surfaces of Non spherical CNTs, one nanometer to several tens of nanometers.
- the distance between the screening electrode 111 and the nanotube 105 is close to the height h CNT of the nanotube.
- the screening electrode 111 is preferably disposed in a plane P comprising the foot conductive surface 105p of the transmitter or located below this plane.
- the insulating zone 115 supports the potential difference between the disk at the base of the nanotube and the screening electrode. The reduction of this voltage makes it possible to limit the induced electrical stress.
- the conductive electrode between the nanotube 105 and the substrate 112 is connected to the output terminal 131 of the SCCO.
- the screening electrode 111 on the surface of the substrate is connected to the input terminal 132 of the SCCO.
- the input terminal 132 of the SCCO is connected to the high voltage HT.
- the optical source 107 illuminates the current source SCCO with a power controlled by the electronic control circuit 109.
- the potential of the output terminal 131 is in this example greater than or equal to the potential of the terminal
- the screening electrode 111 only serves to reduce or eliminate the electric field induced by the anode 106 on the transmitter 105, in normal operation.
- Screening electrode then screens the anode field applied locally to the nanotube, which automatically reduces the CNT emission current I CNT, until the CNT current I delivered by the CNT is equal to the current I SCCO delivered by the current source SCCO.
- the CNT current I delivered by the nanotube or nanotubes automatically adjusts to the current I SCCO delivered by the SCCO.
- This operating mode makes it possible to control the emission current of the nanotube according to a quasi-linear law of the optical power, in this exemplary embodiment (the SCCO being a photodiode or a phototransistor).
- the position of the SCCO 120 outside the vacuum chamber prevents its exposure to generated X-rays.
- the residual flow of X-rays emitted when the power source is not illuminated, OFF state, is then very weak.
- This configuration does not require an active voltage source to handle the voltage of the shielding electrode or to activate the SCCO.
- the high voltage power supply generates only one signal to bias the switchable cathode and the SCCO relative to the anode. It is thus possible to design a very compact high voltage power supply that does not require an isolation transformer in normal operation.
- the anode 106 is grounded which facilitates its cooling.
- the anode 106 may include an opening for the passage of electrons, the anode 106 being connected to a vacuum chamber according to a scheme known to those skilled in the art.
- the source according to the invention is a source of high energy electrons, for example from 20 to 500 kV.
- FIG 3 illustrates an exemplary embodiment of the invention with a CNT network, 105i.
- the elements referenced in this figure have been described previously.
- the figure 4 schematically illustrates the operation of the cathode controlled by the SCCO. It includes the emission current I CNT of a CNT as a function of the potential difference between the nanotube 105 and the screening electrode 111, and this for a constant anode field. It also includes the current I SCCO delivered by the SCCO according to the bias voltage of this SCCO and according to the optical power Popt received by the SCCO.
- the difference in voltage between the nanotube and the screening electrode which is equal to the voltage difference between the output terminal and the input terminal of the SCCO source.
- the current value is the intersection, I s , between the curve 200 of the current delivered by the SCCO and the current curve 201. emission of the nanotube.
- the emission current of the CNT is equal to this current of 10 ⁇ A.
- the delivered current I SCCO by the source is equal to the current value corresponding to the intersection of the curve describing the dark current I obsc and the emission curve. nanotube.
- the dark current of the SCCO source must be extremely low and a voltage across the SCCO current source must be lower than the avalanche voltage of the SCCO source. SCCO.
- the figure 5 represents the voltage difference between a CNT and a shielding electrode allowing a cancellation of the field at the top of the CNT.
- this voltage is 110 V.
- an SCCO that has an avalanche voltage greater than 110V and which has an extremely low dark current.
- the current source SCCO can also feed a network of nanotubes, as will be schematized later.
- the current in the ON state, illuminated current source can reach for example 1 mA.
- An ON / OFF ratio of 10 6 is then obtained.
- the voltage that makes it possible to cancel the field at the top of the nanotube is of the order of 50 V. It is then possible to use SCCOs having a lower avalanche voltage.
- the insulation thickness will be adjusted according to the voltages to be held and the insulating material. For example, 1 .mu.m of thermal silica can hold a voltage of 200V and theoretically 1000V.
- the operating principle of the switchable cathode described above remains the same for this variant embodiment.
- the figure 6 represents an alternative embodiment using an electrical insulating optical fiber for the propagation of the control signal.
- An insulating optical fiber 140 allows the propagation of the signal from the source 107.
- This fiber passes through a dielectric solid 141, such as a polymer, a ceramic, an epoxide, in order to excite the SCCO 120.
- the assembly is disposed in an electrical insulator 142. As in the example of the figure 1 , there is a direct optical link between the optical source and the remote SCCO source.
- the figure 7 illustrates a radiofrequency electromagnetic wave source 180 for controlling the SCCO.
- the radiofrequency source comprises a transmission module 181 and an RF emission antenna 182.
- the SCCO comprises an RF reception antenna 183 connected to a module RF receiver 184, and a current source controlled by this receiving module.
- the SCCO is therefore a source of current controlled by the source of electromagnetic waves 180.
- Such a device does not require any direct link between the RF source and the SCCO.
- This device is particularly well suited for controlling many switchable cathodes carried at high voltage by an electromagnetic wave having different modulations and thus allowing transmission multiplexing and demultiplexing at the reception of each channel, CNT cathode.
- the control can be all or nothing (On / Off) or allow precise control of the current intensity of CNT pulse width modulation or Pulse Width Modulation PWM in Anglo-Saxon.
- the figure 8 schematically a variant for controlling two cathodes C 1 , C 2 by multiplexing Mix.
- This device allows, for example, the RF control and the generation of PWM signals to control the current from a second microprocessor 185.
- the communication between the two RF microprocessors can be done using the SPI protocol for example.
- the figure 9 represents a variant for which the switchable cathode comprises at least two zones 81, 82, or even more than two zones.
- Each zone comprises one or more CNTs 105 and each zone is connected to an output 83s, 84s, of a current source 83, 84 corresponding thereto.
- Each CNT 105 is associated with a screening electrode positioned on either side or around the nanotube as described above.
- One or more laser sources 85, 86 are connected to a control circuit. The operation of this variant is similar to that described for the preceding figures with a greater possibility in the modulation.
- the figure 10 is a sectional view of an example of a solution for eliminating current leaks that may exist on the surface of the insulator 1001.
- the substrate 1000 is covered with an insulating layer 1001 comprising a via 1002 allowing the contact of the base electrode of the nanotube, a screening electrode 111 positioned around the nanotube 105 ( figure 2 ).
- An encapsulation insulator layer 1004 is deposited to cover the shielding electrode and at least partially the base electrode of the nanotube. This arrangement advantageously makes it possible to reduce or even cancel the leakage currents.
- the figure 11 represents a network of nanotubes 105 connected to the substrate through the presence of through contacts 1100, known by the abbreviation TSV (through silicon vias).
- TSV through silicon vias
- the presence of these TSV makes it possible to transfer contacts from the rear face 1101 to the front face 1102.
- they make it possible to electrically control different areas on the chip surface.
- all the CNTs 105 are connected to the substrate 91. Electrically isolated shielding electrodes can be attached to different CNTs areas, thus independently controlling their emission currents.
- the figure 12 schematically an example of individually polarized nanotubes 105 through the presence of through contacts TSV 1100 and the presence of a surface control electrode 1200 common to different nanotubes CNTs.
- the figure 13 describes an example of integration at a surface level.
- an insulating layer 1301 is deposited on the substrate 1300.
- a conductive layer is cut into two disjoint conductive areas, 1303, 1304, but interlaced so as to obtain an interdigitated structure.
- One of the electrodes serves as a base electrode 110 at CNT 105 ( figure 2 ), the other electrode plays the role of screening electrode 111.
- the substrate no longer has an electrical role, only a role of mechanical support.
- the figure 14 gives an exemplary embodiment of different transmission zones 1401, 1402, 1403, 1404, 1405 with individual control of the emitted current.
- Each of the zones has a structure such as that described in figure 12 .
- the different areas are positioned next to each other according to the specifications of the intended application. It is possible carry out a transfer of contacts on the rear face without changing the operating principle.
- the figure 15A and the figure 15B two examples of insulating multilayer structure.
- the figure 15A represents a first embodiment which allows in particular to avoid the risk of current leakage on the surface of the insulation. Is deposited on an insulating substrate a screening electrode 151 having on one part an opening O, on which is deposited an encapsulation insulator 152. The base electrode and the nanotube are arranged vis-à-vis the opening made in the screening electrode.
- the figure 15B schematically a second variant in which is disposed on the insulating substrate, a continuous screening electrode, an encapsulation insulator 154 on which we will position the base electrode 110 and the associated nanotube 105.
- the conductor network at the potential of the nanotubes is separated from the control screening electrode by an insulating dielectric layer.
- the galvanic isolation between the two conductive elements is no longer surface but intrinsic.
- This device is interesting with regard to arcing phenomena, partially conductive deposits may appear in the vacuum electronic tubes and more particularly the RX tubes.
- the control screening electrode preferably operates in self-polarization thus ensuring electrostatic shielding of the main field created by the anode which is carried at high voltage.
- the figure 16 schematizes an example of buried buried electrode structure optimized to minimize the coupling capacitors between the base electrode 110 connecting the CNTs 105 and the buried screening electrode 111 shown in dotted lines, it can take the form of a flat ring and has a certain surface extending outside the surface of the base electrode. This structure makes it possible to envisage operating frequencies greater than frequencies used at a continuous buried screening electrode which exhibits a stronger capacitive coupling with the base electrodes.
- the figure 17 represents an example of an electronic circuit for controlling current of the nanotubes by an optically controlled current source.
- the screening electrode 111 is voltage controlled using a phototransistor, illuminated it is passing.
- the screening electrode 111 in dashed lines, is polarized at the high voltage HT (potential reference of the system). If the phototransistor 171 is unlit, it becomes blocking: the screening electrode 111 is found to be negatively polarized with respect to the high voltage HT thanks to a battery 172 (typical polarization 40V). This makes it possible to control the voltage level of the screening electrode with respect to the potential reference.
- the base electrode 110 is connected to the high voltage HT through a phototransistor 175 which acts as an optically controlled switch.
- the phototransistor 175 Illuminated under strong flux, the phototransistor 175 is fully conducting, thereby providing a direct connection of the base electrode 110 to the high voltage HT. In the absence of light flux, the phototransistor 175 is blocking and the current emitted by the nanotubes 105 equals the dark current of the phototransistor (typically ⁇ 1nA). With intermediate illumination, the current level of the phototransistor can be regulated precisely: the current emitted by the CNTs 105 then equals this current per operating point (cf. figure 2 ). The level of illumination of the phototransistor makes it possible to control the electronic emission level of the CNTs. A Zener diode 176 placed in parallel with the phototransistor 175 makes it possible to avoid overvoltages on the phototransistor 175 and avoids its destruction during uncontrolled events such as breakdowns in the X-ray tube.
- the figure 18 schematizes an example of a network with three connections allowing the use of individual emitters and requiring electrostatic symmetry around the emission axis of a nanotube to minimize electron optical aberrations. Indeed the generated electric field has the symmetry of the electrodes which forms it (near the CNT). Thus a high symmetry is obtained by making a shielding electrode connection and base electrode connected by three channels 191, 192, 193 distributed at 120 °.
- the offset of the SCCO out of the tube offers a greater margin of maneuver on the choice of the SCCO (photo element for example), dimensions, electrical characteristics, resistance in tension, etc.
- the SCCO is no longer subject to the direct environment of the tube, X-rays, bombardment and ion implantation, etc.
- the configuration of the electrodes notably allows a dynamic reconfiguration of the potential in the vicinity of the nanotubes.
Landscapes
- Cold Cathode And The Manufacture (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR1402973A FR3030873B1 (fr) | 2014-12-23 | 2014-12-23 | Source d'electrons de haute energie a base de nanotubes/nanofibres de carbone avec element de commande par onde eletromagnetique deportee |
PCT/EP2015/080990 WO2016102575A1 (fr) | 2014-12-23 | 2015-12-22 | Source d'electrons de haute energie a base de cnt avec element de commande par onde electromagnetique deportee |
Publications (2)
Publication Number | Publication Date |
---|---|
EP3238225A1 EP3238225A1 (fr) | 2017-11-01 |
EP3238225B1 true EP3238225B1 (fr) | 2019-01-30 |
Family
ID=53008567
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP15820149.1A Active EP3238225B1 (fr) | 2014-12-23 | 2015-12-22 | Source d'electrons de haute energie a base de cnt avec element de commande par onde electromagnetique deportee |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP3238225B1 (es) |
ES (1) | ES2721017T3 (es) |
FR (1) | FR3030873B1 (es) |
WO (1) | WO2016102575A1 (es) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR3053830A1 (fr) | 2016-07-07 | 2018-01-12 | Thales | Tube electronique sous vide a cathode planaire a base de nanotubes ou nanofils |
CN111082792B (zh) * | 2019-12-29 | 2024-06-11 | 中国工程物理研究院流体物理研究所 | 一种光控半导体开关 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7085352B2 (en) * | 2004-06-30 | 2006-08-01 | General Electric Company | Electron emitter assembly and method for generating electron beams |
FR2879342B1 (fr) * | 2004-12-15 | 2008-09-26 | Thales Sa | Cathode a emission de champ, a commande optique |
DE102007046278A1 (de) * | 2007-09-27 | 2009-04-09 | Siemens Ag | Röntgenröhre mit Transmissionsanode |
FR2926924B1 (fr) * | 2008-01-25 | 2012-10-12 | Thales Sa | Source radiogene comprenant au moins une source d'electrons associee a un dispositif photoelectrique de commande |
-
2014
- 2014-12-23 FR FR1402973A patent/FR3030873B1/fr not_active Expired - Fee Related
-
2015
- 2015-12-22 ES ES15820149T patent/ES2721017T3/es active Active
- 2015-12-22 WO PCT/EP2015/080990 patent/WO2016102575A1/fr active Application Filing
- 2015-12-22 EP EP15820149.1A patent/EP3238225B1/fr active Active
Non-Patent Citations (1)
Title |
---|
None * |
Also Published As
Publication number | Publication date |
---|---|
FR3030873B1 (fr) | 2017-01-20 |
EP3238225A1 (fr) | 2017-11-01 |
FR3030873A1 (fr) | 2016-06-24 |
WO2016102575A1 (fr) | 2016-06-30 |
ES2721017T3 (es) | 2019-07-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2232520B1 (fr) | Source radiogene comprenant au moins une source d'electrons associee a un dispositif photoelectrique de commande | |
EP0602983B1 (en) | Hybrid photomultiplier tube with high sensitivity | |
EP2583298B1 (fr) | Detecteur a multiplicateur d'electrons comportant une couche de nanodiamant hautement dope | |
EP0376825A1 (fr) | Source d'électrons du type à émission de champ | |
FR2926668A1 (fr) | Source d'electrons a base d'emetteurs de champs pour radiographie multipoint. | |
EP1825490B1 (fr) | Cathode à émission de champ à commande optique | |
EP3238225B1 (fr) | Source d'electrons de haute energie a base de cnt avec element de commande par onde electromagnetique deportee | |
US7687992B2 (en) | Gating large area hybrid photomultiplier tube | |
FR2909484A1 (fr) | Systeme et procede pour limiter les effets d'arcs dans des matrices d'emetteurs de champs | |
EP0589030B1 (fr) | Canon a electrons compact comportant une source d'electrons a micropointes et laser a semi-conducteur utilisant ce canon pour le pompage electronique | |
EP0485266A1 (fr) | Canon à électrons modulé par commutation optoélectronique | |
EP3267463A2 (fr) | Tube electronique sous vide a cathode planaire a base de nanotubes ou nanofils | |
FR2486712A1 (fr) | Tube intensificateur d'images a micro-canaux, et ensemble de prise de vues comprenant un tel tube | |
WO2014095888A1 (fr) | Dispositif d'optique electronique | |
EP0625277B1 (fr) | Ecran plat a micropointes protegees individuellement par dipole | |
FR2644286A1 (fr) | Generateur de faisceau d'electrons et dispositifs electroniques utilisant un tel generateur | |
EP1030341A1 (fr) | Générateur radiofréquence de très grande puissance | |
EP1249028B1 (fr) | Cathode generatrice d'electrons et son procede de fabrication | |
FR3138808A1 (fr) | Dispositif de réduction de la charge électrique d’un véhicule spatial | |
WO2015059250A1 (fr) | Generateur de rayons x a capteur de flux integre | |
WO2010139740A2 (fr) | Source de faisceau electronique collimate a cathode froide | |
EP4162526A1 (fr) | Dispositif optoélectronique pour affichage lumineux et procédé de fabrication | |
WO1992011693A1 (fr) | Dispositif de transmission de signaux a propagation d'ondes et applications dudit dispositif pour l'amplification de tels signaux | |
FR3098010A1 (fr) | Dispositif de generation de rayonnements electromagnetiques et procede de realisation d'un tel dispositif | |
CH191362A (fr) | Analyseur électronique pour émetteur de télévision. |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE |
|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20170608 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
DAV | Request for validation of the european patent (deleted) | ||
DAX | Request for extension of the european patent (deleted) | ||
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
INTG | Intention to grant announced |
Effective date: 20180725 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D Free format text: NOT ENGLISH |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 1093922 Country of ref document: AT Kind code of ref document: T Effective date: 20190215 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D Free format text: LANGUAGE OF EP DOCUMENT: FRENCH |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602015024170 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: NV Representative=s name: SERVOPATENT GMBH, CH |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: FP |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2721017 Country of ref document: ES Kind code of ref document: T3 Effective date: 20190726 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190530 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190430 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 1093922 Country of ref document: AT Kind code of ref document: T Effective date: 20190130 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190530 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190430 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190501 Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602015024170 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
26N | No opposition filed |
Effective date: 20191031 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PCAR Free format text: NEW ADDRESS: WANNERSTRASSE 9/1, 8045 ZUERICH (CH) |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20191231 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20191222 Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20191222 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20191231 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20151222 Ref country code: MT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20190130 |
|
P01 | Opt-out of the competence of the unified patent court (upc) registered |
Effective date: 20230606 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 20231123 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20231116 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20231128 Year of fee payment: 9 Ref country code: FR Payment date: 20231122 Year of fee payment: 9 Ref country code: DE Payment date: 20231114 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 20240115 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 20240101 Year of fee payment: 9 |