DE102007017212A1 - Method and device for cooling a gas - Google Patents

Abstract

The invention provides a method and apparatus for vibration-free cooling of a gas. The gas is brought into thermal contact with a first cooling medium in a first cooling step. Subsequently, in a second cooling step, it flows through a condenser, which is in thermal contact with a second cooling medium, and is thereby cooled by not more than 10 K. This low temperature gradient is largely responsible for ensuring that the gaseous or liquid gas stream leaving the condenser is very homogeneous and laminar. It is therefore suitable for further processing into a stream of solid pellets of the same size. These pellets can be transported over several meters in a vacuum and are therefore suitable as target material for the generation of a plasma by intensive laser irradiation.

Description

The The invention relates to a method and a device for cooling, in particular for liquefaction, a gas.

State of the art

Out many materials generate a plasma by bombardment with intense laser light. Such a plasma emits X-rays as well as extremely ultraviolet (EUV) light off. But it can also be charged particles, such as electrons or protons, accelerate.

There To generate a plasma, a very high laser intensity is necessary is, the irradiated material (target) is at the site of irradiation locally destroyed. For the permanent generation of a plasma therefore a source is needed, the a continuous supply of unconsumed target material supplies.

Out (Ö Nordhage, "On a Hydrogen Pellet Target for Antiproton Physics with PANDA ", Dissertation University Uppsala, ISBN 91-554-6649-4) it is known to add hydrogen first liquefy, the liquid flow with a vibrating nozzle divided into drops and then these drops through further cooling to solidify into pellets. These pellets are used as targets for the investigation of interactions with fast protons at a synchrotron used and could also used in principle for the production of plasmas by laser bombardment become.

adversely are the pellets produced in this way, and therefore also the ones produced from them Plasmas, of strongly varying quality.

Task and solution

It is therefore the object of the invention, a method and an apparatus for cooling to provide a gas whose end product lower quality variations and thus as a raw material for the production of pellet targets for laser bombardment is more suitable than the cooled according to the prior art gas.

These The object is achieved by a method according to the main claim and a device according to the independent claim. Further advantageous embodiments will be apparent from the following referred back Dependent claims. An on-device based plasma source and advantageous Uses thereof are the subject of further ancillary claims.

Subject of the invention

in the As part of the invention, a method for cooling a gas has been developed. In this case, the gas is in a first cooling step through a conduit guided, which is in thermal contact with a first cooling medium.

When cooling medium In principle, any medium is suitable that has a lower temperature as the gas, wherein the temperature preferably both spatially over the Medium is homogeneous as well as temporally constant. It can, for example be a cooled solid, through which the line passes. It can also be a bath of a liquid through which the Line runs. This liquid in particular, a liquefied Kryogas.

Especially advantageous is a liquefied cryogenic gas, which is capable of exchanging steam with the environment, first cooling medium selected. There with the escaping vapor also those taken in its creation Heat of vaporization is discharged to the environment, the temperature of the liquefied increases Cryogenic gas is not over so long its boiling point, as it is not completely evaporated.

In a second cooling step the gas is passed through a condenser guided, which is in thermal contact with a second cooling medium. That's it second cooling medium usually colder as the first one. But it can also be the same temperature as that first cooling medium and in particular be identical to this.

According to the invention, the gas is cooled in the second cooling step by not more than twice, preferably not more than 1.5 times and most preferably not more than 1 times the temperature difference between its melting point and its boiling point. The temperature difference between the melting and boiling points is a material property inherent in the gas. It is for example for H ₂ 6 K, for N ₂ 14 K and for Ar, Kr and Xe 4 K.

This measure has the effect that the flow of the gas in and behind the condenser is particularly homogeneous and particularly laminar. These advantages are particularly evident in a particularly preferred embodiment of the invention, in which the gas is liquefied in the second cooling step: Then there are no places in the flow of the liquefied gas at which it boils or freezes. It has been recognized that such a conditioned flow of liquefied gas can be processed particularly well, for example to droplets of defined size and shape: temperature fluctuations of the liquefied gas cause Geschwin digkeitsschwankungen of emerging from the condenser gas jet. If this gas jet is divided into drops, these speed fluctuations reduce their quality. The measure according to the invention reduces the temperature fluctuations and thus makes it possible to produce liquid gas droplets of better quality.

Experience has shown that quality of the liquefied Gases are best when a constant amount of this gas in the the liquefier is present. This can be achieved advantageously in that the Gas the liquefier exclusively fed in the gas phase becomes. Therefor the gas must not be cooled so much before the condenser that here the temperature falls below the boiling point. Optimally, that will Gas the liquefier with a little bit over supplied to its boiling point temperature, so its temperature in the liquefier only has to be changed by a small amount. The liquefier takes then essentially the energy difference between the gas phase and the liquid Phase of the gas. The gas should not freeze in the condenser since This can otherwise clog.

Of the condenser For example, a chilled solid be in the lead for the gas is introduced. Particularly advantageous is the second cooling medium through the liquefier guided. This transmits less Vibrations on the gas as, for example, a cooling of the condenser with a chiller. It has been recognized that vibrations transmitted through the condenser combine homogeneity and laminar flow of the gas flow Affect liquefier and therefore are to be prevented.

Of the condenser and thus the gas passed through it can be particularly low in vibration cool, if a gaseous second cooling medium chosen becomes. A single gas particle will not have enough momentum to cause a measurable deflection of the massive condenser. The Pulse transfers through the totality of the particles are statistically distributed so that they almost completely pick up and the liquefier Total is not measurable out.

When gaseous second cooling medium For example, the vapor phase is above a liquefied one Kryogas suitable. The steam dissipates heat of vaporization. at constant pressure in the reservoir of the second cooling medium is therefore the evaporation rate and thus the temperature of both the remaining liquefied Gas supply and the vapor phase almost constant. About the pressure in the storage container can the evaporation rate and thus the temperature of the vapor phase of the second cooling medium roughly regulated. The pressure also determines the flow of the second cooling medium, the authoritative for the cooling capacity in the liquefier and thus for the amount of per unit time coolable Gas is.

Advantageous become the gas and the second cooling medium opposite through the liquefier guided. This limits the maximum occurring temperature difference between the two currents, the one turbulence in the flow of the gas, especially if this in the second cooling step liquefied becomes.

In a particularly advantageous embodiment of the invention is the Gas before entering the condenser with the leaking from the condenser second cooling medium in an intercooler placed in thermal contact, for example by a heat exchanger. This reduces the temperature difference in the second cooling step in the liquefier still to be bridged. At the same time, the residual cold from the condenser exiting second cooling medium exploited, so that less of this cooling medium is consumed.

In a further advantageous embodiment of the invention is the Gas between the first cooling step and the intercooler heated for example, with an electric heater. This allows the Inlet temperature of the gas in the condenser particularly sensitive and also be regulated quickly. The temperature of the gas immediately after the first cooling step is only comparatively lethargic to change, because this heats the entire supply of the first cooling medium or chilled would have to be. The in the intercooler caused cooling depends on the outlet temperature of the second cooling medium from the condenser and therefore can not be directly influenced without the temperature conditions in the liquefier to change.

The Temperature of the second cooling medium can be roughly regulate by the pressure in the reservoir of this cryogenic gas, which in turn determines its evaporation rate. Advantageously, the second cooling medium before entering the condenser heated for example, with an electric heater. This warming can both more sensitive than also done faster be considered an indirect temperature change by change the pressure in the reservoir.

If the gas is liquefied by the process according to the invention, a particularly advantageous embodiment of the invention provides for it to be passed through a vibrating nozzle in the liquefied state. This nozzle preferably vibrates parallel to the flow direction of the liquefied gas, and preferably with an amplitude of between 100 and 1000 nm. In this way, the liquefied gas in a stream of drops of consistent shape and Size to be converted. The velocity of the effluent liquefied gas is determined by the pressure at which the gas is supplied to the first cooling step and can be regulated by varying this pressure.

It it was recognized that unwanted Vibrations during cooling of the gas of the prior art, the limiting factor for the quality of the drops and for the constancy of this quality were. Such vibrations have been caused, for example, by use from cooling heads in the gas and introduced into the apparatus. The invention vibration-free cooling avoids such disturbances and allows so the production of drops in not only higher, but also the same lasting quality (especially size) as this was possible according to the prior art.

Out at the vibrating nozzle formed drops can, for example, by bombardment with intense Laser pulses are generated by a plasma, which X-rays and / or extreme Ultraviolet (EUV) light is emitted.

For such and other applications that run in a vacuum, the liquefied gas in a particularly advantageous embodiment of the invention the vibrating nozzle transferred to a vacuum. there It is particularly advantageous in that by the vibration of the nozzle in drops uniform shape and size divided liquefied Solidify gas. This is done by surface evaporation, which adds an extra cooling until it reaches freezing. It then creates a homogeneous Electricity from solid pellets, which transports in vacuum also over longer distances can be. This is particularly advantageous for the bombardment with intense laser pulses. Because the plasma generated thereby considerable amounts of heat and emits high-energy radiation, the shelling should be in a spatial Distance to the source of the pellets take place to this source not to damage.

Advantageous the transfer takes place in the vacuum is spaced from the vibrating nozzle; especially can the liquefied Gas through a chamber in which the same gas is in a gaseous state, be transferred into the vacuum, wherein the gas in the chamber preferably in the vicinity of the triple point located. This includes in particular the combination of a pressure between 0.2 times and 3 times the triple point pressure with a Temperature between 1 times and 1.2 times the triple point temperature to understand. In this way, the homogeneity and flight direction the stream of liquefied Gas or the resulting drop when crossing in the vacuum as much as possible maintained.

Out For the same reason, it is advantageous to pass the liquefied gas through a nozzle in the To transfer vacuum, whose Inner diameter gradually decreases towards the vacuum. It should be the Inner diameter of the nozzle when the gas enters by a factor of at most 10, preferably by one Factor between 3 and 4, be greater as on the vacuum side. Then the speeds of the liquid drops or pellets distributed homogeneously, and the pellet stream is tightly collimated around the target flight direction.

These homogeneity and collimation will be maximal when the pressure gradient is along the nozzle becomes minimal. This can be achieved when the diameter of the Nozzle along their length decreases exponentially and the nozzle also advantageous at least ten times longer than their exit diameter.

In a particularly advantageous embodiment of the invention, the gas is transferred to the vacuum in at least two stages. Advantageously, in the first stage, there is a pressure of 10 ^-5 mbar or more, preferably 10 ^-4 mbar or more, so that the shape of the gas droplets remains frozen when frozen into pellets. Advantageously prevails in the last stage, a pressure of 10 ^-6 mbar or less, preferably 10 ^-7 mbar or less; Since these are typical base pressures of accelerator systems and systems for generating EUV light, the pellets can then be transferred directly to these systems. To realize the steps, for example, a plurality of vacuum chambers with graduated pressures, which are connected to one another in each case by openings or nozzles which can be passed through by the pellets, can be arranged one behind the other in the direction of flight of the pellets. As a driving force for the pellets, the pressure difference between the chambers can be used. If a triple point chamber is present, the transition from the triple point chamber into the first vacuum chamber gives the pellets a much greater acceleration than the transitions between the remaining chambers. If the chambers are arranged one below the other, however, the gravitational field of the earth can also be used as a further propulsion force, whereby this effect is comparatively low (about 15 m / s speed increase to 10 m fall distance).

The Pellets have after being transferred to the Vacuum advantageously a speed of at least 50 m / s, preferably of at least 100 m / s. In the production of plasma from the pellets by means of Laser bombardment, the pellets are evaporated and thus consumed. The speed of the pellet flow and the distances between determine the pellets in the pellet stream about the possible repetition rate.

In particular, He, N ₂ , Ar, Kr and Xe are suitable in gaseous and liquid form. With the method according to the invention, for example, liquid droplets and solid pellets of H ₂ , N ₂ , Ar, Kr and Xe can be produced.

in the The invention also provides a device for cooling a Gas developed in particular for carrying out the method according to the invention suitable is. This device is characterized by a condenser comprising at least two lines through which the gas and a main cooling medium can flow in opposite directions, which are in thermal contact with each other.

These measure has the effect that in the operation of the condenser along the entire length of the two Lines a small temperature difference between these two Lines is adjustable. Is the gas in its warmest or coldest Condition, it is also the second cooling medium. This can be a low temperature gradient over the cross-section of the first conduit can be achieved, reflecting the homogeneity and laminarity of the flow in improved this first line.

This Effect is still in an advantageous embodiment of the invention reinforced by that the two lines arranged parallel or concentric with each other are.

In a particularly advantageous embodiment of the invention is the condenser a pre-cooling medium upstream, which are brought into thermal contact with the gas can. This measure has the effect of making the gas most of the temperature difference between its original temperature and the desired target temperature already in thermal contact with the pre-cooling medium can. Is next to the origin temperature of the gas its maximum Temperature reduction in the condenser given, a lower end temperature is reached.

Advantageous is the pre-cooling medium in a container arranged, through which passes a line through which the gas can flow. A Such arrangement maximizes thermal contact between the gas and the pre-cooling medium.

The container advantageously has a ring shape. Under a ring shape is in To understand in this context every closed form, the one Restricted area in its interior. This area does not have to be circular but may also have an oval or even angular shape; it is through the pre-cooling medium against heat radiation protected from the environment.

Advantageous is the stock of the main cooling medium arranged in this bounded area. Then it avoids that This is overly fast heated. For example, the pre-cooling medium cheaper liquid Nitrogen and the main cooling medium the much more expensive liquid Be helium. heat radiation from the environment consumes additional nitrogen in such an arrangement, not additional Helium.

In a particularly advantageous embodiment of the invention includes the device a condenser downstream nozzle, which has means for generating a vibration. As a means for generating the vibration are in particular piezoelectric means suitable. One in the condenser liquefied laminar stream produced Gases can through this nozzle with a suitable choice of the vibration amplitude defined in drops be broken up.

In a further advantageous embodiment of the invention includes the device at least one of the nozzle downstream vacuum chamber. Then you can exit from the nozzle Drops liquefied Gases at the transition freeze into pellets in the vacuum chamber. It was recognized that solid pellets a longer Distance between the place of their production and the place of their use return can liquefied as drops Gas. The pellets can then, for example, form a pellet target that in a defined Interaction zone interacts with radiation from a radiation source. Such a pellet target has the advantage that the target material can be replenished continuously in the interaction zone.

Around To obtain the shape of the drops when frozen can be beneficial several vacuum chambers with graduated pressures arranged one behind the other be.

Advantageous the vacuum chamber is spatially from the nozzle spaced, such as by a triple point chamber, in conditions close to the triple point of the gas. Then get the liquid drops after exiting the nozzle the opportunity to stabilize before solidifying into pellets become.

In An advantageous embodiment of the invention is the entrance in the vacuum chamber is designed as a further nozzle whose Inner diameter gradually decreases towards the vacuum. It should be the Inner diameter of the other nozzle on the inlet side is larger by a factor of at most 10 as on the vacuum side. Then there are the speeds the entering into the vacuum chamber liquid droplet or Pellets homogeneously distributed, and the pellet flow is tight around the target flight direction collimated.

In the context of the invention, a Plas found a source. This contains a directed to an interaction zone radiation source and the inventive device for cooling a gas. The device is arranged to emit cooled gas into the interaction zone. As a radiation source, in particular a laser is suitable.

It it was recognized that such a plasma source operated continuously can be and at the same time is more durable than plasma sources the state of the art. The gas as the target material, which when bombarded is consumed with the beam from the radiation source, regardless of his State of aggregation be supplied continuously. Will it be from emits the device in the form of pellets, the device advantageous in a big one Distance (order of magnitude 1 m and more) from the interaction zone. Then it will be not by the heat and radioactive radiation of the plasma damaged.

Advantageous the plasma source comprises a cold trap, which absorbs the portion of the gas that does not emit the jet the radiation source interacts. The cold trap is preferably in the flow direction of the gas or in the direction of flight of the solid pellets behind the zone in which the gas or pellets interact with the beam. The capture of excess gas residues as well used pellets in the cold trap improved the vacuum in the plasma source and reduces the to maintain this vacuum required pump power.

The Plasma generated with the plasma source can be X-ray and extremely ultraviolet (EUV) generate radiation. In such a plasma is also the acceleration charged particles, such as electrons and protons, at energies of several 100 MeV possible. Thus, the plasma source for example, in a device for photolithographic structuring of semiconductors as a source for EUV radiation serve. But it can also be used for example in a particle accelerator become. The zone where the cooled gas (preferably in the form of pellets) and the accelerator beam interact, is then extremely compact to build.

Special description part

following the object of the invention is explained in more detail with reference to figures, without that the subject of the invention is limited thereby. It is shown:

1 : Exemplary embodiment of the device according to the invention and the method according to the invention

2 : Hydrogen drops produced by the process according to the invention.

3 : Local distribution of 20 μm diameter hydrogen pellets about 1.2 m from the triple point chamber.

4 : Embodiment of the device according to the invention with a plurality of vacuum chambers.

1 shows an embodiment of the inventive device as well as for the inventive method in cross-section. Through a container 1 for the liquid precooling medium (first cooling medium) 2 runs a sinuous line 3 in which the gas to be cooled 4 is cooled in a first cooling step. Inside of the container 1 bounded area 5 there is another container with a supply of main cooling medium (second cooling medium) 6 ,

The gas 4 can optionally by heating 7 be heated before passing through a heat exchanger 8th in thermal contact with that from the condenser 9 exiting main cooling medium 6 is brought. Subsequently, the gas enters the condenser 9 one. From the main cooling medium 6 the vapor phase is via a pipe 10 fed to the condenser. The condenser 9 converts the gas 4 in a liquid flow, passing through a vibrating nozzle 11 is broken into drops. These drops can then be solidified by surface evaporation upon passage into vacuum.

In one embodiment of the process, hydrogen is used as the gas 4 used. The pre-cooling medium 2 is liquid nitrogen, the main cooling medium 6 is liquid helium. The hydrogen is cooled down from room temperature (293 K) to 81 K in the first cooling step. The heating system 7 is not used in this embodiment. The vapor phase of helium has a temperature of 4.5 K on exiting the liquid helium reservoir and entering the condenser 9 a temperature of 5.05 K. When entering the heat exchanger 8th It is 16.2 K warm and cools the incoming hydrogen to 21 K, before it is cooled in the condenser to 16.9 K and thus liquefied.

Through the vibrating nozzle 11 the jet of liquid hydrogen turns into drops 12 of the same size, which are introduced into a filled with gaseous hydrogen triple point chamber (70 mbar, 14 K).

Two different types of vibrating nozzles were used: brass edged glass nozzles with inside diameters between 12 and 12 inches 40 μm and stainless steel nozzles with inner diameters between 16 and 40 μm. Glass nozzles have smoother inner surfaces and, being transparent, allow optical control of their function during operation. Stainless steel nozzles are more reproducible to produce, and their exit ports have a better (ie, smaller) length to diameter ratio. Thus, a lower pressure is needed to drive liquefied gas through stainless steel nozzles.

2 shows the out of the vibrating nozzle 11 in the triple point chamber exiting hydrogen droplets. These pass from the chamber through a further nozzle with 600 microns vacuum-side inner diameter in a first vacuum of 10 ^-2 mbar and thereby freeze to pellets. The droplets or pellets are accelerated by the gas flow from the triple point chamber in the direction of vacuum. Through another nozzle, the pellets pass into a second vacuum of 10 ^-4 mbar and from there through a tube of 2 cm diameter in an interaction zone in which they are bombarded with laser light. This interaction zone may be several meters away from the triple point chamber. It was possible to observe pellets of consistent quality with diameters between 18 and 60 μm at a distance of 1.2 m from the triple point chamber. The pellet diameter corresponds essentially to the final diameter of the vibrating nozzle 11 between condenser and triple point chamber.

The spatial and the angular distribution of the pellets and their velocities were observed with CCD cameras. After crossing into the first vacuum have pellets of 30 microns Size an average Speed of about 70 m / s. Over a period of a few Seconds is the size of the pellets stable up to 1%, over a period of several hours up to 10%.

The radius R _{c of} the nozzle for the passage into the vacuum tapers in this embodiment exponentially with the coordinate x along the nozzle: R c = R 1 + R 2 * Exp (-δ · x) where δ is a free taper parameter and R ₁ and R ₂ depend on the radius R _max on the inlet side and the radius R _min on the vacuum side as follows:

3 shows the local distribution of 20 μm diameter hydrogen pellets in a plane perpendicular to the direction of flight about 1.2 m from the triple point chamber. Plotted is the relative abundance n in arbitrary units over the deviation Δx of the pellets from the main flight direction. The pellet jet is very well collimated; by far the majority of pellets deviate by less than 200 μm from the main flight direction. This is due to the fact that the liquid hydrogen jet is broken up into drops very regularly. The cause of this, in turn, is that of the vibrating nozzle 11 a so homogeneous and laminar hydrogen flow is supplied. Currently, about 30% of all reach the vibrating nozzle 11 Pellets produced the interaction zone.

4 shows an embodiment of the device according to the invention. The nozzle 11 flows into a triple point chamber 20 , In operation, there is a pressure between 0.2 times and 3 times the triple point pressure. The temperature is between 1 times and 1.2 times the triple point temperature. In the direction of flight of the drops 12 one behind the other are vacuum chambers 21 . 22 and 23 arranged through which the drops 12 gradually transferred to the vacuum. Here are the drops 12 in the triple point chamber 20 still fluid and freeze when passing into the chamber 21 , The chambers 21 . 22 and 23 are among themselves as well as from the triple point chamber 20 by permeable to the pellets nozzles 24 separated. In the first chamber 21 In operation, there is a pressure of the order of 10 ^-4 mbar, in the last chamber 23 a pressure of the order of 10 ^-7 mbar.

The device comprises a laser (not shown) whose beam 25 in an interaction zone with the drops frozen into pellets 12 interacts. Unused pellets are in a cold trap 27 collected.

Claims (45)

Method for cooling a gas with the steps: - the gas is in a first cooling step guided by a line, which is in thermal contact with a first cooling medium; - the gas is in a second cooling step through a condenser guided, which is in thermal contact with a second cooling medium, and is in order not more than twice the temperature difference between cooled at its melting and boiling point. A method according to claim 1, characterized in that the gas in the second step by no more than 1.5 times the temperature difference between its melting and its boiling point is cooled. Method according to one of claims 1 to 2, characterized that the second cooling medium colder is the first. Method according to one of claims 1 to 3, characterized that a liquefied Kryogas, which is able to exchange steam with the environment, as first cooling medium chosen becomes. Method according to one of claims 1 to 4, characterized that the second cooling medium through the liquefier guided becomes. Method according to claim 5, characterized in that that the gas and the second cooling medium in opposite directions the liquefier guided become. Method according to one of claims 1 to 6, characterized that a gaseous second cooling medium is selected. Method according to one of claims 5 to 7, characterized that the gas before entering the condenser in an intercooler with the from the liquefier exiting second cooling medium is brought into thermal contact. Method according to one of claims 1 to 8, characterized the gas is heated between the first cooling step and the intercooler. Method according to one of claims 1 to 9, characterized that the gas in the second cooling step liquefied becomes. Method according to claim 10, characterized in that that liquefied Gas through a vibrating nozzle is directed. Method according to claim 11, characterized in that that the nozzle parallel to the flow direction of the liquefied Gases vibrate. Method according to claim 12, characterized in that that the nozzle vibrated with an amplitude between 100 and 1000 nm. Method according to one of claims 11 to 13, characterized that the liquefied gas from the vibrating nozzle is transferred into a vacuum. Method according to claim 14, characterized in that that liquefied Gas when transferring to the vacuum is solidified. Method according to one of claims 14 to 15, characterized that the overpass in the vacuum is spaced from the vibrating nozzle. Method according to one of claims 14 to 16, characterized that the liquefied gas through a chamber in which the same gas is in gaseous state is present, is transferred to the vacuum. Method according to claim 17, characterized in that the gas in the chamber is near the triple point. Method according to one of claims 14 to 18, characterized that the liquefied gas through a nozzle is transferred into the vacuum, whose Inner diameter gradually decreases towards the vacuum. Method according to claim 19, characterized that the inner diameter of the nozzle at Entry of the gas by a factor of at most 10 is greater as on the vacuum side. Method according to one of claims 14 to 20, characterized that the gas is transferred to the vacuum in at least two stages. A method according to claim 21, characterized in that in the first stage, a pressure of 10 ^-5 mbar or more, preferably 10 ^-4 mbar or more, prevails. Method according to one of claims 21 to 22, characterized in that in the last stage, a pressure of 10 ^-6 mbar or less, preferably 10 ^-7 mbar or less prevails. Method according to one of claims 14 to 23, characterized that the gas after transferring into the vacuum is a speed of at least 50 m / s, preferably of at least 100 m / s. Method according to one of claims 1 to 24, characterized in that at least one gas from the group (He, N ₂ , Ar, Kr, Xe) is selected as the coolant. Device for cooling a gas, characterized through a condenser comprising at least two of the gas and a main cooling medium opposite flow-through Lines that are in thermal contact with each other. Apparatus according to claim 26, characterized by condenser comprising two lines arranged parallel to one another. Device according to one of claims 26 to 27, characterized through a condenser comprising two concentrically arranged lines. Apparatus according to any of claims 26 to 28, comprising the liquefier upstream pre-cooling medium, which can be brought into thermal contact with the gas. Device according to claim 29, characterized in that that the pre-cooling medium in a container is arranged, through which a flow-through of the gas line runs. Apparatus according to claim 30, characterized by a ring-shaped Container. Device according to one of claims 30 to 31, characterized by an imprisoned in the container Area arranged supply of the second cooling medium. Device according to one of claims 26 to 32, characterized by a downstream of the condenser Nozzle, which Means for generating a vibration has. Apparatus according to claim 33, characterized by piezoelectric means for generating the vibration. Device according to one of claims 33 to 34, characterized through at least one of the nozzle downstream Vacuum chamber. Apparatus according to claim 35, characterized by several successively arranged vacuum chambers with graduated To press. Device according to one of claims 35 to 36, characterized that the vacuum chamber spatially from the nozzle is spaced. Apparatus according to claim 37, characterized by a triple point chamber as a means for spacing the vacuum chamber from the nozzle. Device according to one of claims 35 to 38, characterized that the inlet into the vacuum chamber designed as another nozzle is, whose inner diameter steadily decreases towards the vacuum. Device according to claim 39, characterized in that that the inner diameter of the other nozzle on the inlet side to a factor of at most 10 is larger as on the vacuum side. Plasma source with one on an interaction zone directed radiation source, characterized by a device according to one of the claims 26 to 40, which is arranged to be cooled gas can emit into the interaction zone. Plasma source according to claim 41, characterized by a laser as a radiation source. Plasma source according to one of claims 41 to 42, characterized by a cold trap to absorb gas that is not with the beam from the radiation source interacts. Apparatus for photolithographic structuring of semiconductors, characterized by a plasma source after a the claims 41 to 43. Particle accelerator, characterized by a Plasma source according to one of claims 41 to 43.