EP1464060A1

EP1464060A1 - Method and device for production of radio-isotopes from a target

Info

Publication number: EP1464060A1
Application number: EP02806546A
Authority: EP
Inventors: Stéphane Lucas; Ray Bricault
Original assignee: Ion Beam Applications SA
Current assignee: Ion Beam Applications SA
Priority date: 2001-12-21
Filing date: 2002-12-23
Publication date: 2004-10-06
Anticipated expiration: 2022-12-23
Also published as: DE60220316T2; DE60220316D1; US20050069076A1; ATE363126T1; EP1321948A1; WO2003063181A1; EP1464060B1

Abstract

The invention relates to a method for production of a radio-isotope (4) form a target (3), containing a precursor (1) of said radio-isotope (4), using a beam of accelerated particles, comprising the following method steps: preparation of a target (3), containing the precursor (1) of the radioisotope (4), irradiation of said target (3) within an irradiation chamber (10) with a beam of accelerated particles in order to induce the transmutation of the precursor (1) into the radio-isotope (4), heating said target (3) in order to bring about the efflux of the radio-isotope (4) from the target (3), collection of said radio-isotope (4), extracted as a gas and condensation of said radio-isotope (4) into a solid or liquid. The invention further relates to a device for carrying out the above method and use of the device and method for the production of palladium 103 from rhodium 103.

Description

PROCESS AND DEVICE FOR THE PRODUCTION OF RADIO-ISOTOPES

FROM A TARGET

Subject of the invention

The present invention relates to a method and a device for the production of radioisotopes from a target essentially consisting of an isotope precursor which is irradiated by a beam of accelerated particles, the radioisotope once produced being separated from its precursor.

A particular application of the present invention relates to the production of palladium 103 from rhodium 103.

State of the art

The usual production of radioisotopes is carried out by bombardment or irradiation of a target essentially consisting of an isotope precursor using a beam of accelerated particles.

There is a nuclear reaction which causes a fraction of the isotope precursor present to be transformed into a radioisotope. It should be noted that in most cases, the radioisotope created is intimately mixed with the isotope precursor material constituting the target and therefore remains in said target. It should also be noted that usually only a few percent of the precursor are transformed into exploitable radioisotopes. Several types of methods have been proposed for separating the radioisotope from its precursor. One of them essentially consists of a chemical separation according to which the target is completely dissolved, for example in a strong acid. Filtration is then carried out and optionally electro-dissolution of the radioisotope and finally precipitation of the latter. As an example of this chemical separation method, the rhodium-palladium 103 pair can be cited. The target consists of rhodium, as an isotope precursor, deposited on a copper support. This target is subjected to irradiation with a 14 MeV proton beam for 6 days, which induces a reaction 103 p ^ _ 103 p ^ _e - (- allows to obtain that approximately 1% of rhodium 103 is transformed into palladium 103. Once the irradiation is complete, the target is discharged and brought to an armored enclosure called a "hot cell" which is intended to allow the separation of the isotope from its precursor. [0008] In order to separate the palladium rhodium, the separation procedure described above is used. In particular, the target consisting of the copper support and the rhodium-palladium mixture in solid form is dissolved with a strong acid solution such as an NH3 + H2SO4 mixture. This dissolves the copper and keeps the rhodium and palladium in the form of precipitates. It is then sufficient to carry out a filtration. The separation of the palladium from the palladium-rhodium mixture will be obtained by electro-dissolution of the m mixture into a solution of hydrochloric acid with chlorine flow to improve performance (Applied Radiat. Isot. 38 (2), pp. 151-157 (1987)), followed by a separation step carried out for example by complexation of the palladium with using alpha-furil dioxin (AFD) in order to selectively extract palladium by the liquid-liquid extraction method (Radiochim. Radioanal. Lett. 48 (1), pp.15-19 (1981)). A final precipitation ends the process to isolate the palladium 103 from the rhodium 103 and condition it in the desired form.

It is also possible to cause chemical dissolution of rhodium 103 in order to recover only the palladium 103 by means of a NaAuCl4 solution (Appl. Radiât. Isot. 48 (3), pp.327-331 (1997) )) and to separate the rhodium from the palladium using a solution of α-benzoinoxime (ABO).

However, we first observe that whatever the separation methods used, the maximum yield ever achieved described in the literature is around 90%.

In addition, the implementation of such techniques is complex and there is generation of effluents which can prove to be dangerous and polluting. It should also be noted that unfortunately, this separation process completely destroys the target, and therefore rhodium, which is a particularly expensive material. Consequently, the target cannot be reused for a future irradiation. In addition, the acid solutions used for the separation will be polluted by radioactive waste and will require decontamination, which significantly increases the cost of the process.

Finally, to perform the last precipitation, a trainer is necessary, for example palladium 102, the use of which reduces the specific activity of palladium 103. Document US 5,468,355 describes in detail a process for the production of ¹³ N oxides comprising a step of bombarding a carbon-based target with a beam of high energy charged particles, so as to generate a layer of ¹³ N on the surface of the target, then a step of combustion of the target in the presence of gaseous oxygen so as to extract from said target the oxides of ¹³ N. This document also mentions another embodiment for extracting a radioisotope of a bombed target, by heating, without combustion of said target. The document thus evokes an embodiment in which a target containing ¹⁰ B or B as a precursor is, after bombardment, heated and swept by a gas such as helium to extract the radioisotope ^{1: L} C ^therefrom . However, the document does not detail the implementation of this other form of execution.

Document US 5,987,087 describes a process for extracting, by selective heat treatment, from a target based on arsenic, previously irradiated with a beam of charged particles, the selenium-72 radioisotope produced following this irradiation. In this process, the target material once irradiated is mixed with a metallic reagent, such as stainless steel filings, or aluminum, before undergoing heat treatment. Obtaining this mixture makes it possible to obtain a differentiated sublimation of arsenic (precursor) and selenium-72 (radioisotope of interest). The heat treatment consists in heating in two stages the target once irradiated and then mixed with the metallic reagent. In the first step, the mixture is heated to a temperature between 1000 ° C and 1100 ° C. In a second step, a second heating is carried out at 1300 ° C. of the mixture so as to cause the sublimation of selenium-72 which is harvested for example on a cold support. Selenium-72 is then recovered separately. In other words, in this document, there is an intermediate stage of treatment between the irradiation of the target and the stage of thermal treatment in order to separate the radioisotope of interest which is selenium-72. The heat treatment is not done directly on the target but on the target mixed with a metallic reagent. In addition, the method of this document makes use of a ^'stream of a purified inert gas. Furthermore, the problem that US 5,987,087 seeks to solve, which is that of extracting selenium-72 produced from an arsenic-based target, and the solution which it proposes, relate only to 'to a very special case of precursor / radioisotope.

Aims of the invention

The present invention aims to provide a method and a device for producing radioisotopes which does not have the drawbacks of the state of the art. The present invention aims to provide a solution which reduces the production of radioactive waste.

The present invention further aims to provide a method in which the target is not destroyed, and can therefore be reused for a new production of radioisotope.

The present invention further aims to provide a radioisotope with a high specific activity.

Main characteristic elements of the invention The present invention relates to a process for producing a radioisotope of interest from a target comprising a precursor of said radioisotope, with using an accelerated particle beam, said method comprising the following steps:

- preparation of a target comprising the precursor of the radioisotope, - irradiation, within an irradiation chamber, of said target by a beam of accelerated particles, with a view to inducing the transmutation of the precursor into radio- isotope,

heating of said target with a view to causing the radioisotope to effuse out of the target,

- Collecting said extracted radioisotope in gaseous form and condensing said radioisotope in solid or liquid form.

Note that in the following description, the expressions "radioisotope" and "radioisotope of interest" will be used interchangeably to designate the radioisotope that one seeks to produce, while the term " precursor ”will designate, as its name indicates, the element from which it is sought to obtain said radioisotope of interest.

In the method according to the invention, the radioisotope of interest is generally obtained by irradiation using a proton beam of a solid target containing the precursor, the radioisotope of interest being produced within said target, also preferably in solid form.

The target, in the present invention, therefore comprises: before irradiation: the precursor, optionally linked to a metal support; after irradiation: the precursor, possibly linked to a metallic support, and the radioisotope of interest. The separation of the radioisotope of interest and the precursor will therefore consist in subjecting the solid target to a heat treatment to obtain an effusion reaction, that is to say thermal separation of the radioisotope of interest.

The heat treatment in order to cause the effusion of the radioisotope of interest, is therefore carried out in the present invention, directly on the irradiated target, and not on a mixture which would be constituted by the irradiated target then mixed to a metallic reagent such as stainless steel or aluminum filings, unlike the process described in document US Pat. No. 5,987,087. In other words, in the process according to the invention, it is not necessary to subject the target after irradiation to a treatment before heating it in order to extract the radioisotope of interest.

For this purpose, it must be precursor / radioisotope couples of interest which have relatively different melting and boiling temperatures from each other, so that the treatment of effusion makes it possible to obtain a diffusion of the radioisotope within the target itself, its extraction or escape by evaporation and sublimation, while the target precursor remains present within said target preferably in solid form. It should therefore be understood that in the present invention, the concept of effusion refers to a physical phenomenon "wider" than sublimation and must be understood as comprising the phenomenon of sublimation. More specifically, the melting temperature of the radioisotope of interest is less than the melting temperature of the precursor by at least 100 ° C.

It is also important to emphasize that, in the present invention, the precursor therefore remains at the pure state, that is to say that it can be recovered at the end of the process, without it being necessary for this to perform an additional extraction or treatment step. In other words, once the radioisotope has been extracted from the target, said target can be directly recovered without further processing. In the case where it is subsequently desired to reuse said precursor, this characteristic of the invention allows a certain time saving, while ensuring a better reuse yield.

The heat treatment used to obtain the effusion of the radioisotope of interest can be any treatment operating by the Joule effect. For example, the energy intended for heat treatment can come from irradiation by a beam of charged particles such as electrons, by the beam used for the nuclear reaction, by infrared radiation, by laser treatment. , by plasma treatment or any other suitable heat treatment.

For example, heating under vacuum or under a controlled inert atmosphere will quickly obtain the desired effusion effect. It should therefore be understood that in the present invention, one does not circulate gas such as oxygen during the heat treatment which is subjected to ^' the irradiated target.

In general, there is a relationship between the speed of effusion of an element contained in a heated target and its diffusion coefficient, to the extent that a certain number of parameters which determine the speed of effusion influence also the diffusion coefficient. Among the parameters determining the effusion speed, we find: the melting temperature of said element relative to the target; the vapor pressure of the element of the diffusing element; - the energy of activation of the diffusion; the nature of the target (metal or ceramic, for example); and the size of the diffusing element, more precisely its ionic radius. Thus, it is possible to separate Zn from a target of Y by effusion by heating the target to a temperature above 900 ° C., from Be to a target of Zr by heating the target to a temperature above 1100 ° K, Pd of a Rh target by heating the Rh target to a temperature above 1000 ° C.

To summarize, we see that the speed of effusion of an element (radioisotope) is all the more important as its ionic radius is small: the effusion from a tantalum target is thus two times faster for berillium than for barium. It will also be noted that the speed of effusion of an element increases with temperature according to an exponential law.

The effusion speed of an element

(radioisotope) also depends on the crystallographic structure of the target. Thus, if during the heating of the target, a recrystallization takes place, there is a reduction in the number of grain boundaries at the level of the crystal and the diffusion of the element can then take place both through the joints and between the joints, which has the effect of affecting the speed of effusion of said element.

We can finally note that the particle beam can influence the effusion rate of the radio- isotope. Indeed, the speed of effusion will be different according to the defects created by this beam within the target, between the surface of the target and the position in the target at the level of which the radioisotope is generated by nuclear reaction. It is thus known that the mechanisms referenced in the literature under the abbreviations “RED” (Radiation Enhanced Diffusion) and “RES” (Radiation Enhanced Ségrégation) and which are linked to the diffusion mechanisms (interstitial, diffusion, etc.), either drastically increase the diffusion coefficient, and therefore the speed of effusion, by creating gap movements on the diffusion path, or on the contrary considerably reduce the diffusion by creating precipitation sites on the diffusion path.

According to a first embodiment of the present invention, the heat treatment will occur within an effusion chamber separate from the irradiation chamber in order to obtain said effusion. According to a more preferred embodiment, the collecting and condensing step can also be carried out within said effusion chamber. For this purpose, and in a particularly advantageous manner, this effusion chamber will be provided with means for collecting and condensing said extracted radioisotope.

The collection and condensation means can be constituted by a collection substrate such as a ceramic, metallic or polymeric support, cold or cooled. Preferably, this substrate will have low adhesion characteristics.

According to this embodiment, an additional step of separation of the radioisotope extracted, collected and condensed on the collection substrate should be produce. Optionally, this separation step could be carried out within a separation enclosure separate from the effusion enclosure. Advantageously, this separation enclosure comprises a bath of acid solution in which the collection substrate can be soaked in order to obtain a separation of the radioisotope from said collection substrate. Then, it will be necessary to filter and separate said radioisotope in order to condition it in the desired form. According to another embodiment, the heat treatment can be carried out directly within the irradiation chamber, for example directly by irradiation with the beam of charged particles which made it possible to carry out the transmutation of the radioisotope. . Another object of the invention relates to a device for implementing the process for producing a radioisotope, said device comprising the following means:

Means for irradiating a target comprising an isotope precursor in order to induce a transmutation of the precursor into the radioisotope,

Heating means for causing the effusion of the radioisotope within said target,

- means for collecting and condensing the extracted radioisotope.

Preferably, the means for collecting and condensing the extracted radioisotope consist of a cold collection substrate.

Preferably, the collection substrate has an interlayer having low adhesion characteristics with the radioisotope. Preferably, the device according to the invention further comprises means for separation of the radioisotope from said collection substrate.

Advantageously, the separation means are constituted by a separation enclosure comprising a bath of acid solution in which is disposed the collection substrate with the radioisotope.

The present invention also relates in particular to the use of said method and said device for the production of palladium 103 from rhodium 103. In other words, it relates to the reaction 103Rh (p, n) 103p ^ _by irradiation of a proton beam. Other examples of pairs of metals can of course be envisaged for the implementation of the method (for example the couples l ^ In / l ^ Cd, ¹⁹⁷ Hg / ¹⁹⁷ Au, ⁹⁵ Tc / ⁹⁵ Mo, Zn / Y, Be / Zr, Ou / Ni).

BRIEF DESCRIPTION OF THE FIGURES FIGS. 1a and 1b schematically describe the various steps of the process for preparing the radioisotope according to a first and a second embodiment of the present invention, respectively. Figures 2a and 2b respectively describe the effusion and separation chambers used for the implementation of the methods according to the present invention.

FIG. 3 describes a second embodiment in which the steps of irradiation and effusion can be carried out directly on-line within the irradiation chamber. Figures 4a and 4b schematically describe a particle accelerator which can be used for the implementation of the method. Figure 4a corresponds to a perspective view of this device, while FIG. 4b corresponds to a top view.

Description of several preferred embodiments of the invention

The figure schematically describes the various stages of a first embodiment of the method for producing a radioisotope according to the present invention. Reference is made to the preparation of the radioisotope lO- ^ pc ^ referenced 4, from a target 3 comprising rhodium lO ^ pj- ^ isotope precursor, referenced 1, by irradiation with a beam of protons.

Initially, it is first of all to prepare the target 3 comprising the precursor 1 of the radioisotope 4 (step A-preparation of the target). To do this, Rh is deposited on a metal plate 2 which is in this case a copper plate. This is usually done by electrolysis, so as to obtain a deposit of a thickness such that the proton beam used during irradiation (for example a proton beam of 14 MeV) loses at least three quarters of its energy within of the target. However, other deposition techniques such as evaporation, plasma deposition techniques (direct current (DC), radiofrequency or microwave) under vacuum or atmospheric plasma (plasma spraying) can be used.

In the case of a target 3 inclined at 10 ° relative to the direction of the beam, a thickness of 50 μ is sufficient for 14 MeV protons. Once the target 3 has been made, it is loaded into a cyclotron and subjected to a proton beam with an energy of 14 MeV for 6 days (step B- irradiation). The transmutation of l ° ³ Rh into l ° ³ Pd takes place at the rate of 0.225 mCi / mAH. At the end of 144 hours, a production of 28.8 Ci will be obtained for a current of 1 mA continuous, and taking into account the decrease.

It should be noted that the quantity of ^ O ^ Pd (radioisotope 4) harvested corresponds to less than 1% of the initial quantity of (precursor 1) present on target 3.

In this first embodiment of the invention, it is necessary to maintain the temperature of the target 3 at all times below the effusion temperature of the palladium in the rhodium. If this were not so, the palladium would exit the target, and condense on the surrounding walls. The irradiated target 3 is then discharged and transferred (step C-extraction and transfer) to an effusion chamber 17 as shown in FIG. 2a. This effusion chamber is a shielded enclosure in which effusion is carried out (step D). The shedding of a constituent out of an alloy (apart from this alloy) is based on the following physical phenomena. The most volatile constituent (here palladium) passes into the gas phase from the surface, which causes a difference in concentration of volatile constituent between the surface and the interior of the target. A flow of diffusion of the volatile constituent, from inside the target, towards the surface, then arises. Evaporation of the volatile component continues, and reduces the concentration of volatile component within the target. Finally, the vapor of the volatile component is condensed and collected on a cold surface. Note that it is necessary for the volatile component to have a lower melting temperature than that of the other components of the alloy, or a higher partial vaporization pressure for a given temperature. Palladium and rhodium have melting temperatures of 1554.9 ° C and 1964 ° C respectively. Within the effusion chamber 17, the target 3 is heated, for example by means of electric heating, by Joule effect or by induction, of an electron beam, of infrared, of a laser, or a DC plasma or radio frequency or microwave. The next step is then to collect and condense the palladium 4 extracted from the target 3 on a collection support 5 (step E) to then separate and collect it (step F), for example in the form of PdCl ₂ . Figure 2a describes an effusion chamber 17 used according to the first embodiment of the method of the invention. It is of course a shielded enclosure into which the irradiated target 3 is transferred (step C of FIG. La) and which makes it possible to carry out the effusion steps (step D) of the radioisotope 4 outside the target. 3 but also of capture and condensation (step E) of said radioisotope 4 extracted.

This target 3 is preferably heated under vacuum or under a controlled atmosphere using heat treatment means 18 in order to cause the diffusion of palladium 4 within the target 3 to its surface and its evaporation / sublimation out of it. A temperature between 800 ° C and 1750 ° C is suitable for causing the effusion of palladium 4 out of the rhodium matrix (target 3).

Advantageously, the heat treatment means 18 are in the form of a simple electrical resistance. They must act in a minimum of time and must be very simple to regulate. In addition, they must make it possible to preserve target 3 and to save its integrity in order to allow its subsequent use for future irradiations.

The evacuation and maintenance of the effusion chamber 17 under vacuum are ensured by a vacuum pump 19.

Palladium 4 present in the effusion chamber 17 in gaseous form is collected and condensed (step E of Figure la) on a support 5 collection. The collection support 5 is cold or cooled, to a temperature below the condensation temperature of palladium 4. Palladium 4 is collected in solid or liquid form. Said substrate ^' 5 is placed near the target under a protective bell 20.

Particularly advantageously, the collection substrate 5 is a cold ceramic or metal support and it has poor adhesion. It may for example have a non-adherent interlayer (not shown). For example, soluble polymers or greases can be used to make this interlayer.

At the end of the effusion and collection operation (steps D and E), the target 3 still contains practically the initial amount of rhodium, and it has not been affected mechanically or chemically. It can therefore advantageously be reinstalled in the irradiation chamber, for a new palladium production campaign (step G). Then, the collection substrate 5 is transferred using a transfer system to another enclosure called separation enclosure 21 in which the separation step (step F of FIG. La) of the radioisotope 4 and collection substrate 5 is performed. FIG. 2b describes such a separation enclosure 21 to which the collection substrate is brought.

Advantageously, this separation enclosure 21 comprises a bath 22 of a solution so as to release the ^ - ^^ Pd (radioisotope 4) in said solution. This separation can be obtained by chemical means, such as dissolving the interlayer and / or palladium, and / or mechanical means such as stirring.

Then, this solution is treated so as to isolate the 103pd (radioisotope 4) (step F of FIG. La) which is packaged in small vials using dose dispensers (“doses dispenser”) . The activity of each vial is measured for control, and the product can then be used as a radiochemical.

It should be noted that the various elements of the effusion chambers 17 and separation 21 must be such that they are easily decontaminable, can be integrated within a shielded "hot-cell" enclosure, equipped with a system adequate transfer of the target 3, the irradiation chamber 10 to the effusion chamber 17, and the collection substrate 5 from the effusion chamber 17 to the separation chamber 21 and are easy to interview.

The target 3 transfer system and the collection substrate 5 must itself be easily removable, for example for verification, and easily decontaminable. It must also be secure. The effusion chamber 17 and separation chamber 21 can be combined into a single enclosure. FIG. 1b schematically describes the various steps of a second embodiment of the method for producing a radioisotope according to the present invention, in which the effusion step is carried out on-line, that is to say directly within the irradiation chamber.

The constitution of the target (step A) is done in the same way as in the first embodiment. As shown in Figure 3, a collection substrate 5 is installed in the irradiation chamber. It is therefore not necessary to extract the target 3 to proceed to effusion-collection. This device makes it possible to carry out irradiation and effusion-collection simultaneously (steps B, D e ^' t E simultaneous). The energy required to heat the target is provided in whole or in part by the beam of accelerated particles. At the end of the irradiation, the collection substrate 5 is extracted from the irradiation chamber 10. The separation of the deposited palladium (step F) is then carried out in the same manner as in the first embodiment. The target 3 may remain within the irradiation chamber 10. [0083] FIG. 3 therefore describes a device suitable for the implementation of the second embodiment of the method of the invention. In the irradiation chamber 10 are installed the target 3 as well as the collection substrate 5. A set of vacuum pumps makes it possible to reach, step by step, the high vacuum level required within the accelerator. Figures 4a and 4b schematically describe a particle accelerator which can be used for the implementation of the method. More specifically, Figure 24a is a perspective view of this accelerator, while Figure 4b is a top view of the same device. As illustrated in these figures, the particle accelerator 7 comprises: a source capable of generating a particle beam, - the accelerator 6 itself, a circuit 9 for routing the beam, a deflection magnet 11 which allows the particle beam to be directed either to a pumping system

12 intended to control the quality of the beam parameters, either to a shielded enclosure 10 constituting the irradiation chamber placed at the end of the line. Between the accelerator 6 and the deflection magnet 11, the device 7 further comprises a series of auxiliary magnets which correspond to quadrupoles 13 and to sextupoles 14 and which have the function of ensuring focusing of the beam.

It will also be noted that just at the outlet of the accelerator 6 there are collimators 15. [0088] Furthermore, a scanning magnet 16 makes it possible, as the name suggests, to scan the target 3 using of the radiation beam.

Conventionally, there is the target 3 obtained in the chamber 10 at the end of the beam line of the accelerator 6 of charged particles. Advantageously, the accelerator 6 can be constituted by a cyclotron which makes it possible to generate a beam of protons having a certain divergence and which is corrected by the presence of the collimators 15.

These collimators 15 are essentially intended to prevent part of the beam (20%) from hitting elements of the beam line and damaging them.

Advantageously, these collimators 15 can be removable and themselves coated with a layer of rhodium, so as to take advantage of the beam loss to directly produce lO ^ pα (radioisotope 4).

For this purpose, the collimators 15 must be able to meet the following requirements: ease of assembly / disassembly and placement in the line, very good cooling of the irradiated surface, ease of transfer to a lead container, ease of disassembly in a “Hot cell”, minimum copper substrate mass, minimum rhodium surface to be covered, reuse for each irradiation of a maximum of components.

Target 3 can also be installed directly inside the particle accelerator 6. Both in the first and in the second embodiment of the invention, target 3 and the collection substrate 5 can be used several times successively. This provides an economical rhodium process, producing little waste. The invention should not be considered as limited to the preferred embodiments described above. In particular, the target can consist entirely of the isotope precursor, or of an alloy comprising this isotope precursor.

Claims

1. Method for producing, using an accelerated particle beam, a radioisotope (4) from a target (3) comprising a precursor (1) of said radioisotope (4), said method comprising the following steps:

- preparation of a target (3) comprising the precursor (1) of the radioisotope (4),,

- irradiation, within an irradiation chamber (10), of said target (3) by a beam of accelerated particles, with a view to inducing the transmutation of the precursor (1) into the radioisotope (4), Heating of said target (3) in order to cause the radioisotope (4) to effuse out of the target (3),

- Collecting said radioisotope (4) extracted in gaseous form and condensing said radioisotope (4) in solid or liquid form.

2. Method according to claim 1, characterized in that the condensation of the radioisotope (4) in liquid or solid form is carried out by contact of the radioisotope (4) in gaseous form with suitable solid means, the radioisotope (4) being in a subsequent step separated from said medium.

3. Method according to claim 2, characterized in that it further comprises a step of conditioning said radioisotope (4) produced in a suitable liquid or solid form.

4. Method according to one of claims 1 to 3, characterized in that the heating is obtained by the Joule effect, a treatment with a beam of charged particles such as electrons, by radiation infrared, by laser treatment, by plasma treatment.

5. Method according to claim 4, characterized in that the heating is carried out under vacuum or under a controlled inert atmosphere.

6. Method according to any one of the preceding claims, characterized in that the heating is carried out within an armored effusion enclosure (17) situated outside the irradiation chamber (10).

7. Method according to claim 6, characterized in that the collecting and condensing step is carried out within said effusion enclosure (17).

8. Method according to any one of claims 1 to 5, characterized in that the steps of irradiation, heating and collection and condensation of the extracted radioisotope are carried out online within the irradiation chamber (10 ).

9. Method according to any one of the preceding claims, characterized in that at the end of the heating step, the target (3) is reused for a new irradiation step.

10. Device for implementing the process for producing a radioisotope (4) according to any one of the preceding claims, said device comprising the following means:

- means for irradiating (6,7,8,9,10) a target (3) comprising an isotope precursor (1) in order to induce a transmutation of the precursor (1) into the radioisotope (4)

heating means in order to cause the effusion of the radioisotope (4) within said target, - means for collecting and condensing the extracted radioisotope.

11. Device according to claim 10, characterized in that the means for collecting and condensing the extracted radioisotope consist of a cold collection substrate (5).

12. Device according to claim 11, characterized in that the collection substrate (5) has an interlayer having low adhesion characteristics with the radioisotope (4).

13. Device according to claim 12, characterized in that it further comprises means for separating the radioisotope from said collection substrate.

14. Device according to claim 15, characterized in that the separation means consist of a separation enclosure (21) comprising a bath (22) of acid solution in which is disposed the collection substrate (5) with the radio- isotope (4).

15. Use of the method according to one of claims 1 to 9 or of the device according to one of claims 10 to 14 for the production of palladium 103 from rhodium 103.