EP1372183A2 - High-temperature oven for solid samples evaporation in an electron-cyclotron-resonance ion source - Google Patents

Abstract

The oven at the end, is symmetrical about the axis. The open end of the cup (4) faces the ion source and has a rod joined to the inner conductor at its outer base. The external conductor (6) is out of contact with the rod and reaches up almost to the cup base, forming the filament holder. A free-standing heating coil (2) surrounds the cup. This contacts the cup wall at one end and the end face of the external conductor (6) facing the cup at the other. The cup, attached inner conductor and external conductor, are made from electrically-conducting material which is dimensionally-stable at over 2000degreesC. The heating coil is a tungsten alloy, introduced free of mechanical stress. At the highest operating temperature, it is dimensionally-stable, or at least cannot move into contact with other components. The rod is plugged detachably into a bush (10), being inserted to a given axially length and surrounded completely by it and equally-spaced spring contacts. The current supply (21) and lead through (16) of the thrust unit comprises an axial, alloy rod of good thermal- and electrical conductivity, which resists tension, compression and torsion.

Description

The invention relates to a high-temperature furnace for solid evaporation in E lektron- Z yklotron- R esonanz- I on OURCES q, ECR IQ, in international usage even under ECRIS, E lectron- C yclotron- R esonance- I on- S ource known. The high-temperature furnace is electrically and mechanically coupled to a coolant-driven push rod device, with which it can be pushed through a guide tube flanged onto the recipient / vacuum housing into the evaporation position depending on the material to be evaporated and fixed or withdrawn therefrom without ventilation of the EZR-IQ. A pulling slide is flanged to this guide tube on the environment side, in order to enable the high-temperature furnace to be inserted or removed without recipient ventilation.

The high temperature furnace is important for metal ion generation, since these are only obtained from a vaporous medium can be. To do this, the corresponding metal must first be evaporated depending on the metal temperatures well above 1000 ° C are necessary.

The constant use of an EZR ion source has shown that the production of an ion beam from solid-state atoms takes a considerable amount of time. As soon as the material is used up or another solid is to be used, i.e. after each opening of the ion source, a pumping phase of several hours has to be accepted. This is used to achieve the required high vacuum of around 10 ^-7 mbar. This problem was first solved with a high-temperature furnace, as is known from DE 196 05 171. The structure of the high-temperature furnace and the materials used for it only allow operation in the temperature range from about 500 ° C to about 1500 ° C, so many metallic elements for evaporation are excluded because the temperatures required with this system, in which a heating wire is on one ceramic base body is wound, can not be reached. The ceramics available in this temperature range become chemically reactive at the high temperatures and therefore cannot achieve the long service life required.

The desire to provide vaporous metallic elements which only evaporate above 1500 ° C to about 2000 ° C also the problem that this invention that this problem solves, is based, namely such a high temperature furnace with at least one crucible volume as from the prior art known with sufficient heating capacity for the to provide evaporating amount of metal. In particular it says the requirement in the room to provide a metal vapor from uranium oxide in order to be able to use it in the EZR-IQ to create.

In claim 1, the high-temperature furnace with its characteristic Features described that solves the task or the Requirement met to also be able to provide uranium atoms. behind it the technical task is the one with maximum temperature load Materials / alloys required evaporation performance to provide, but also the previous exchange friendliness of the high temperature furnace at least.

The high-temperature furnace at the end of the entire arrangement lies coaxial to the axis of the same and consists of a to Ionic source open, cup-shaped crucible, at the bottom outside a stem, the inner conductor, attaches. Surrounds the stem concentric, without touching it, until just before the The outer conductor reaching the bottom of the cup, the filament holder. Cup and style consist of one body and are made of a material that meets the extreme thermal requirements Preservation of the geometric form has grown. For temperatures up to just over 2000 ° C, only tungsten is found as suitable, but it is very difficult to edit to measure is.

That is why a special, highly heat-resistant tungsten alloy is used such as tungsten cerium oxide or tungsten lanthanum oxide or Tungsten thorium oxide used (claim 2). Wolfram is there each doped with 1 to 2% of the respective oxide. Across from The Wolram cerium oxide alloy does not have pure tungsten here important advantage of the lower electron work function. Tungsten-lanthanum oxide has better creep resistance than tungsten, a higher recrystallization temperature high degrees of deformation and in particular an even higher heat resistance. Tungsten thorium oxide has one compared to pure tungsten higher recrystallization temperature, higher heat resistance, a lower electron work function and a good one mechanical workability, but the problematic Disadvantage: it is radioactive. For the high temperature furnace is of manufacturing, machinability, and use, high heat resistance, seen from the tungsten-lanthanum oxide alloy preferable.

The outer conductor is also extremely high in operation Exposed to temperatures, but not to the extent that Cup / crucible that is directly illuminated. On the outer conductor attaches the heating coil / spiral. As material for the outer conductor tantalum or molybdenum or niobium or tungsten is suitable (Claim 3). If still a reasonably good mechanical one Machinability is required, tantalum is preferred.

The heating coil, which is only available with, sits around the cup at one end the rim of the cup and at the other end the contact the forehead facing the outer conductor. The The heating coil is free of tension and pressure, i.e. without mechanical tension installed and deforms even under the highest loads at most only so far that the exposed area is still nowhere touched. The heating coil is made of a special Tungsten alloy that keeps the extreme loads constant in shape endures. So far, only so-called vacuum-metallized has been considered Wolfram, or VM-Wolfram for short, from Plansee Aktiengesellschaft in A-6600 Reute / Tirol.

The current transitions from the component are closed for operation Construction component essential. It is allowed even at high thermal load to no current density increases that completely lead to rapid self-destruction. For this purpose, the stem is in the end area in front of its free forehead over a given axial length and around the full circumference around by means of a socket (10) around the circumference evenly distributed spring contacts with one on the free forehead the push rod inner part of the pushing device (13) releasably inserted. Experience has shown that this component has proven itself proven long-term and is other contacting measures think.

The pusher has mechanical and electrical functions. Mechanically because the high-temperature furnace is in position with it pushed / rotated or pulled out of it. Electric because the heating current via the power supply and current feedthrough flows. A copper-beryllium alloy fulfills all of them Operating requirements satisfactory.

In addition to the construction principle characterized in claim 1, subclaims 4 to 7 describe measures which support stable long-term behavior and user friendliness:
The current feedthrough is an assembly, that is to say a prefabricated component, made of a central copper rod with a sleeve of dielectric, ceramic material that is pushed over it. Aluminum oxide, Al ₂ O ₃ , for example, proves to be well suited. This Al ₂ O ₃ sleeve is in a metallic ring pot sleeve, which, when hard-soldered to the copper rod, is fixed in place. A metallic sleeve is also pushed over the forehead over the other forehead area. Both metallic sleeves are made of a weldable iron-nickel alloy, for example FeNi42, and do not touch (claim 4).

In order to generate heat with as little loss as possible inside the cup, sets according to claim 5 on the free forehead of the cup a surrounding Shielding tube that the heating coil at least completely covered. In this shield tube is a cylindrical one Shielding with at least the length of the installed heating coil pushed. Both shields are inserted with the one in between corrugated reflective tape at a distance from each other held, it touches both point and / or at most only linear in sections. It is an effective heat shield built up and heat conduction to the inevitable Dimension limited. Both shields and the foil are made of a heat-resistant material, e.g. Tantalum.

The guide tube is metallic and has good heat conductivity. It overlaps the shielding tube in every working position of the high temperature furnace and forms an annular gap with it. The vastness of the On the one hand, annular gaps leave an electrical potential difference between the guide tube and the shield to and is on the other hand at most so far that the microwave from the EZR-IQ cannot penetrate yet, for example highest 1/10 of the wavelength of the microwave. So that's the High temperature furnace including a pushing device from the microwave in the Containers are shielded so that no destructive coupling can enter the oven and the pusher. The Oven can have a different electrical potential than that Guide tube are placed (claim 6), that is for certain Use in an accelerator system is important.

The flat contact on the handle of the furnace is to be avoided of selective current density increases imperative. The commercially available ODU contact from Otto Dunkel Mühldorf am Inn meets the requirements for nominal operation long-term (claim 7). One based on this principle Plug contact sits in the forehead protruding into the surroundings (the power supply) of the inner part of the assembled Push rod. The mating contact for the power connection is on the outer tube in the extension to the rear outside of the recipient in the clamp for axial positioning of the high-temperature furnace, there is also an ODU plug contact built-in.

Using a free-standing heating coil, for example 17 turns, which can be selected at over 2000 ° C the materials used and the type of construction less than 0.7 mm in the implementation example presented below sagging is new, including the use of a Push rod with two functions, which on an outer diameter of just 13 mm as an example, not just a coaxial one Water supply and discharge includes, but also the supply and discharge the required heating current of ~ 35 A at a voltage of ~ 12 V in the implementation example.

The completely insulated furnace system can operate on a separate voltage be placed because the all enveloping leadership or Housing tube with the inserted high temperature furnace Inner tube, middle tube and outer tube nowhere over the entire length touched metallic.

The use of materials with a required vapor pressure of 10 ^-3 Torr at up to 2000 ° C in an oven for solid-state evaporation with the smallest dimensions is possible. The furnace can be easily put to another potential.

Figur 1 den an die Schubeinrichtung andockenden Hochtemperaturofen;

Figur 2 die Positionierungseinrichtung und den Kühlmittelanschluss;

Figur 3 den Zusammenbau insgesamt.

The invention is further illustrated by the drawing. The drawing consists of 3 figures. In detail shows:

1 shows the high-temperature furnace docking on the pusher;

Figure 2 shows the positioning device and the coolant connection;

Figure 3 shows the overall assembly.

The implementation example is exemplary. The freestanding Heating coil 2 is for the application in the ion source Accelerator system designed by GSI. The geometric contours are adapted to the plant. The principle is on other use cases transferable and can in its masses and interpretations be modified accordingly.

The high-temperature furnace contains a 30 mm free-standing heating coil 2 with a total of 17 turns. This heating coil 2, which is made from vacuum m metallized tungsten, VM tungsten, from Plansee, becomes so hot during operation that the useful material can be heated to just over 2000 ° C. Due to the special design and the selected material, the heating coil 2 bends only minimally, and at most to such an extent that no contact with another component of the high-temperature furnace can occur in any intended operating case, apart from the electrical contacting on the respective forehead electrical short circuit does not occur in nominal operation.

The assembled push rod consists of various components over its length, on the one hand those for the central electrical line, namely the power supply 21 with its ODU piercing contact 47 on the forehead to the surroundings, which is screwed into the assembled power feed-through 16, the push rod inner part 13 being included the current feedthrough 16 is screwed and is placed on the stem of the crucible holder 4 via the ODU contact 10. This overall electrically centrally conductive connection is surrounded by ceramic tubes for electrical insulation in the area of the power supply 21 and half of the power feedthrough 16, in the area of the inner rod part 13 with the ceramic tube 12, in the area of the stem 4 with the ceramic retaining pin 8. These ceramic tubes 20, 12, 8 are all made of Al ₂ O ₃ . The coaxial electrical return line consists of the outer conductor 6, the filament receptacle 6, around the stem 4, it is clamped via threaded pins 23 to the front push rod part 9, which itself is screwed to the push rod outer part 14, which in turn is screwed to the push rod rear part 15. The push rod rear part 15 is brazed to the outside of the cylindrical sleeve of the current feedthrough 16.

The outer tube is brazed to the rear part 15 of the push rod 17 and leads to the coolant connection F. The inner tube 19 is welded to the sleeve on the current feedthrough 16 on the inside and also leads to the coolant connection F. The center tube sits coaxially between the outer tube 17 and the inner tube 19 18 with its beveled forehead in the area of the screw connection of power supply 21 and power feedthrough 16 am Push rod rear part 15, there is also the coolant deflection.

The guide ball ring 11 made of Al ₂ O ₃ in the end region of the stem 4 keeps this structure coaxial in the housing tube 48, forming a gap.

With this construction, there is, on the one hand, the closed coolant circuit and the ambient air pressure becomes immediate along the power supply 21 to the ring pot-shaped Holding sleeve guided on the assembled power feedthrough 16.

This structure and the use of ODU contacts can required heating power of about 400 W the high temperature furnace are fed. The push rod is with the conventional slightly varied (outer diameter push rod 13 mm) Lock system introduced in the EZR-IQ.

A. Die freistehende Heizwendel 2 ist aus dem hochtemperaturfester Wolframdraht, der im ppm Bereich mit Aluminium- und Kaliumsilikat dotiert wurde und dadurch eine extrem große Formstabilität und Warmfestigkeit hat. Das ist zwingend, weil sonst eine Durchbiegung des Heizdrahtes bis zur Tiegelaufnahme 4 zum zerstörerischen Kurzschluss führt.

B. Die Tiegelaufnahme besteht aus eine Legierung aus Wolfram mit 2% Lanthanoxid. Die Tiegelaufnahme hat über eine Länge von etwa 55 mm keine Führung, steht also frei. Daher kommt als Material bei diesen hohen Temperaturen nur Wolfram in Frage. Reines Wolfram ist sehr schwer zu bearbeiten, spanabhebend nur bei über 200°C. Die Legierung ist schon bei Raumtemperatur bearbeitbar und hat darüber hinaus eine noch höhere Warmstandfestigkeit.

C. Der Ring 11 mit zum Kugelmittelpunkt symmetrischer Kugelstumpfaußenwand ist aus Keramik (Al₂O₃), er zentriert den Hochtemperaturofen auf die Achse.

D. Das Außenrohr 17 aus Stahl der Norm 1.4301 sowie die Stromdurchführung 16 sind mit dem Schubstangenhinterteil 15 aus der Kupferlegierung CuBe2 vakuumdicht hartverlötet.

E. Die koaxiale Wasserkühlung des Schubrohres unterbindet eine Überhitzung der Rundschnurringe 37 aus Fluorkautschuk, FPM, Handelsnahme: Viton® sowie der Schleusenteile 30/31/32/34 aus PEEK. Dadurch kann der Hochtemperaturofen ohne lange Abkühlzeiten aus der Ionenquelle herausgezogen werden und ist sofort durch einen bereitstehenden anderen austauschbar.
Die Teile 9/14/15 des Schubrohres sind aus der Kupferlegierung CuBe2, um eine gute Wärmeableitung bei möglichst großer Härte zu erreichen.
Die konfektionierte Stromdurchführung 16 wird mit dem Innenrohr 19 vakuumdicht WIG geschweißt; der Innenleiter ist aus Kupfer; die aufgeschobene dielektrische Hülse, Keramikisolierung, ist aus Al₂O₃ und wird durch die im Bild linke Ringtopfhülse, die am zentralen Kupferleiter hart angelötet ist, ortsfest gehalten; die im Bild rechte, die Stirn der Al₂O₃-Hülse überragende zweite Hülse berührt die linke Hülse nicht; beide metallischen Hülsen sind hier aus der FeNi42-Legierung.

F. Der Kühlmittelanschluss 27 - das Kühlmittel ist hier Wasser - und das Mittenrohr 18 sind miteinander vakuumdicht hartverlötet. Das Kühlmittel umströmt die Stromzuführung 21 nicht unmittelbar. Durch den Aufbau mit den drei Rohren, Innen-, Mitten- und Außenrohr, besteht Luftdruck der Umgebung bis zur Stromdurchführung 16 hin.

G. Das Führungsrohr 48 ist aus Kupfer, der Kleinflansch 50 ist aus Edelstahl, beide sind mit dem Anschlussflansch 49 vakuumdicht hartverlötet.

I. Der Zugschieber H und das Kreuzstück 55 sind über die drei Spannringe 53 eingebaut. Damit wird, abhängig vom Vorhaben, belüftet und evakuiert. Am Kreuzstück 55 wird gleichzeitig der anliegende Druckzustand gemessen.
Nach dem Herausziehen des an die Schubeinrichtung gekoppelten Hochtemperaturofens bis hinter den letzten der drei Spannringe 53, siehe gestrichelte Position, wird der Zugschieber geschlossen und das hintere Schleusenteil 29 - 34 zusammen mit dem Hochtemperaturofen und dem Schubrohr abgenommen, ohne die EZR- IQ zu belüften.

K. Die zwei Dichthülsen 31/32, die Endkappe 34, das Schleusenhinterteil aus PEEK und die Rundschnurringe 37 aus FPM, Handelsname Viton®, sind zur Dichtung gegen das Vakuum und zur Führung des Schubrohres. Durch Anziehen der Schleusenüberwurfmutter 33 aus Aluminium kann der Anpressdruck auf die Rundschnurringe 37 erhöht werden. Beim Wechsel des Hochtemperaturofens wird die Schleusenüberwurfmutter 33 soweit gelöst, das der Druck der Rundschnurringe 37 eine axiale Verschiebung des Schubrohres zulässt. Ein Verschieben des Hochtemperaturofens in das Schleusenvorderteil ohne einem Druckanstieg in der IQ kann durchgeführt werden.

L. Mit dem Klemmstück 25 aus Aluminium wird die axiale Position des Hochtemperaturofens fixiert. Darüber hinaus wird dort die Stromversorgung über einen ODU-Kontakt 39 angeschlossen. Der zweite Anschluss 47 für die Stromversorgung sitzt an der in die Umgebung gerichtete Stirn der Schubeinrichtung.

N. Der Wasseranschluss 27 besteht aus genormten Schnellwechselkupplungen. Der Hohlraum zwischen dem Innenrohr 19 und dem Mittenrohr 18, beide aus Stahl der Norm 1.4301, dient zur Zuführung, der Hohlraum zwischen dem Mittenrohr 18 und dem Aussenrohr 17, ebenfalls aus dieser Stahllegierung, zur Abführung des Kühlwassers.

The structure of the high-temperature furnace with pusher is as follows:

A. The free-standing heating coil 2 is made of high-temperature-resistant tungsten wire, which has been doped in the ppm range with aluminum and potassium silicate and therefore has extremely high dimensional stability and heat resistance. This is imperative, because otherwise bending the heating wire up to the crucible holder 4 leads to a destructive short circuit.

B. The crucible holder consists of an alloy of tungsten with 2% lanthanum oxide. The crucible holder has no guide over a length of about 55 mm, so it is free. Therefore, only tungsten can be used as material at these high temperatures. Pure tungsten is very difficult to machine, cutting only at over 200 ° C. The alloy can be processed at room temperature and also has an even higher heat resistance.

C. The ring 11 with a spherical stump outer wall symmetrical to the center of the ball is made of ceramic (Al ₂ O ₃ ), it centers the high-temperature furnace on the axis.

D. The outer tube 17 made of steel of the 1.4301 standard and the current feedthrough 16 are hard-soldered to the rear part 15 of the copper alloy CuBe2 in a vacuum-tight manner.

E. The coaxial water cooling of the push pipe prevents overheating of the round cord rings 37 made of fluororubber, FPM, trade name: Viton® and the lock parts 30/31/32/34 made of PEEK. As a result, the high-temperature furnace can be pulled out of the ion source without long cooling times and can be replaced immediately by another one that is ready.
The parts 9/14/15 of the push tube are made of the copper alloy CuBe2 in order to achieve good heat dissipation with the greatest possible hardness.
The assembled current feedthrough 16 is welded to the inner tube 19 in a vacuum-tight manner; the inner conductor is made of copper; the slide-on dielectric sleeve, ceramic insulation, is made of Al ₂ O ₃ and is held in place by the ring pot sleeve on the left, which is hard-soldered to the central copper conductor; the second sleeve on the right, protruding from the front of the Al ₂ O ₃ sleeve, does not touch the left sleeve; both metallic sleeves are made of the FeNi42 alloy.

F. The coolant connection 27 - the coolant here is water - and the center tube 18 are brazed to one another in a vacuum-tight manner. The coolant does not flow directly around the power supply 21. Due to the structure with the three tubes, inner, middle and outer tube, there is air pressure in the environment up to the current feedthrough 16.

G. The guide tube 48 is made of copper, the small flange 50 is made of stainless steel, both are vacuum-brazed to the connecting flange 49.

I. The slide valve H and the cross piece 55 are installed over the three clamping rings 53. Depending on the project, this is used to ventilate and evacuate. At the cross piece 55, the applied pressure state is measured at the same time.
After pulling out the high-temperature furnace coupled to the pusher to behind the last of the three clamping rings 53, see dashed position, the slide valve is closed and the rear lock part 29 - 34 is removed together with the high-temperature furnace and the push tube without venting the EZR-IQ.

K. The two sealing sleeves 31/32, the end cap 34, the lock rear part made of PEEK and the round cord rings 37 made of FPM, trade name Viton®, are used to seal against the vacuum and to guide the push tube. By tightening the lock nut 33 made of aluminum, the contact pressure on the round cord rings 37 can be increased. When changing the high-temperature furnace, the lock nut 33 is loosened to such an extent that the pressure of the round cord rings 37 permits an axial displacement of the push tube. The high-temperature furnace can be moved into the front part of the lock without an increase in pressure in the IQ.

L. The axial position of the high-temperature furnace is fixed with the clamping piece 25 made of aluminum. In addition, the power supply is connected there via an ODU contact 39. The second connection 47 for the power supply is located on the forehead of the pusher facing the surroundings.

N. The water connection 27 consists of standardized quick-change couplings. The cavity between the inner tube 19 and the center tube 18, both made of steel of the standard 1.4301, is used for supply, the cavity between the center tube 18 and the outer tube 17, also made of this steel alloy, for removing the cooling water.

Ein Test ohne Materialfüllung bei einer Temperatur von 1950°C bis 2050°C lief über 200 Stunden unproblematisch.

Ein weiterer Test betraf den Dauerbetrieb über mehrere Tage mit Verdampfen von Vanadium bei Temperaturen bis 1900°C durchgeführt. Aus dem Becher des Hochtemperaturofens ins Plasma gelangende Vanadiumatome waren so zahlreich, gelangten in solcher Zahl in das Plasma und wurden darin zumindest in solcher Zahl ionisiert, dass Ionenströme bis ~ 200 µA daraus extrahiert werden konnten.

The implementation example described has passed initial tests:

A test without material filling at a temperature of 1950 ° C to 2050 ° C ran without problems for 200 hours.

Another test concerned continuous operation over several days with vanadium vaporization at temperatures up to 1900 ° C. Vanadium atoms coming into the plasma from the beaker of the high-temperature furnace were so numerous, came into the plasma in such numbers and were ionized therein at least in such numbers that ion currents of up to ~ 200 µA could be extracted from them.

LIST OF REFERENCE NUMBERS

1 shielding tantalum 2 heating coil VM-W 3 shielding tantalum 4 crucible recording W (2% LaO) 5 ceramic ring Al ₂ O ₃ 6 Filamentaufnahme tantalum 7 furnace operation molybdenum 8th retaining pin Al ₂ O ₃ 9 Pushrod front CuBe2 10 ODU contact Ø 3 socket Brass 11 guide ball Al ₂ O ₃ 12 Ceramic tube 1 Al ₂ O ₃ 13 Pushrod inner part CuBe2 14 Push rod outer part CuBe2 15 Pushrod rump CuBe2 16 Current feedthrough Al ₂ O ₃ / FeNi42 / copper 17 outer tube 1.4301 18 middle tube 1.4301 19 inner tube 1.4301 20 Ceramic tube 2 Al ₂ O ₃ 21 power supply CuBe2 22 Hexagon socket set screw M 3 x 4 with tip 1.4301 23 Hexagon socket set screw M 3 x 3 with tip 1.4301 24 Hexagon socket set screw M 3 x 3 with tip 1.4301 25 clamp aluminum 26 Reinforcement tube 1 1.4301 27 water cooling 1.4301 28 Reinforcement tube 2 1.4301 29 Lock front 1.4301 30 Lock rump PEEK 31 Sealing sleeve 1 PEEK 32 Sealing sleeve 2 PEEK 33 Lock nut aluminum 34 endcap PEEK 35 Round cord ring Ø 20 x 2.5 FPM (Viton) 36 Allen screw M3 x 16 1.4301 37 Round cord ring Ø 13 x 2.2 FPM (Viton) 38 Hexagon socket screw M5 x 25 1.4301 39 ODU contact Ø 4 plug Brass 40 Round cord ring Ø15 x 2 FPM (Viton) 41 Union nut Gyrolok Ø 15 1.4401 42 Round cord ring Ø 11 x 1.5 FPM (Viton) 43 Walther coupling plug 1.4571 44 Walther coupling socket 1.4571 45 Union nut Gyrolok □ 8 1.4401 46 Round cord ring Ø 6 x 2 FPM (Viton) 47 ODU contact Ø 4 socket Brass 48 housing tube copper 49 flange copper 50 Small flange DN 16 ISO KF 1.4404 51 Support ring DN 16 ISO KF 1.4404 52 Round cord ring Ø 18 x 5 FPM (Viton) 53 Clamping ring DN 16 ISO KF 1.4404 54 Pull valve DN 16 ISO KF Aluminum / 1.4404 55 Cross piece DN 16 ISO KF 1.4404 56 reflective tape tantalum

Claims (7)

High-temperature furnace for solid-state evaporation in electron cyclotron resonance ion sources, EZR-IQ,
electrically and mechanically coupled to a pusher with which it can be pushed into the evaporation position and locked or pulled out of it without ventilation of the EZR-IQ through a guide tube flanged to the recipient / vacuum housing and a flanged slide valve attached to it,
characterized in that the high-temperature furnace located at the end of the arrangement sits coaxially with the axis of this arrangement,
that from a crucible (4) open towards the ion source, which consists of a cup with a stem attached to its outer bottom, the inner conductor, and
the outer conductor (6), the filament receptacle, which does not touch this stem and which reaches just before the bottom of the cup, and
the heating coil (2) standing free around the cup, which contacts the cup rim with one end and with the other end the face of the outer conductor (6) facing the cup,
consists,
wherein the cup (4) with attached inner conductor (4) made of an electrically conductive material that can be thermally loaded up to over 2000 ° C. without changing the shape and
the outer conductor (6) consists of the same,
the heating coil (2) is made of a tungsten alloy, which, when used without mechanical tension, does not change its shape at the highest nominal temperature or at most only changes to such an extent that it cannot come into contact with other components,
that the handle (4) in the end region in front of its free forehead is releasably inserted over a predetermined axial length and around the full circumference by means of a bushing (10) made of spring contacts which are equally distributed around the circumference, with a push rod inner part (13) docking on the free forehead of the pushing device is
that the power supply (21) and the power feed-through (16) of the thrust device coupled to it each consist of an axially extending rod made of an alloy that is electrically conductive, heat-conductive and mechanically resilient to tension, pressure and torsion. High-temperature furnace according to claim 1,
characterized in that the cup (4) with attached inner conductor (4) is made of a high-temperature tungsten alloy, such as tungsten cerium oxide or tungsten lanthanum oxide or tungsten thorium oxide. High temperature furnace according to claim 2,
characterized in that the outer conductor (6) is made of tantalum or molybdenum or niobium or tungsten. High temperature furnace according to claim 3,
characterized in that the current feedthrough (16) is an assembly made of a rod-shaped, electrically highly conductive material such as copper with a sleeve of dielectric, ceramic material which is pushed over and which is held in place at one end region via a metallic ring pot sleeve on the copper rod (16) and on the other forehead area is surrounded by a metal sleeve up to and beyond the forehead, the two sleeves not touching High temperature furnace according to claim 4,
characterized in that a surrounding shielding tube (1) attaches to the free face of the cup and at least completely covers the heating coil (2),
in this shielding tube (1) a cylindrical shield (3) with at least the length of the built-in heating coil (2) is pushed, which is held in position with a corrugated reflective film (56), the two shields (1) and (3) at points and / or if necessary touched linearly in sections and these three parts (1), (3), (56) are made of a heat-resistant, metallic material. High temperature furnace according to claim 5,
characterized in that the guide tube (48) is metallic and has good thermal conductivity and the shielding tube (1) does not overlap in any contact position in any working position of the high-temperature furnace,
the annular gap between the guide tube (48) and the shielding tube (1) is at least to the extent that a different electrical potential can be maintained and at most is to the extent that the microwave cannot penetrate from the EZR-IQ. High temperature furnace according to claim 6,
characterized in that the flat electrical contact device (10) between the stem (4) and the push rod inner part (13) is an ODU contact.

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