WO2006034779A1

WO2006034779A1 - Multilayered construction body protecting against radiation

Info

Publication number: WO2006034779A1
Application number: PCT/EP2005/009706
Authority: WO
Inventors: Georg Fehrenbacher; Torsten Radon
Original assignee: Gesellschaft für Schwerionenforschung mbH
Priority date: 2004-09-24
Filing date: 2005-09-09
Publication date: 2006-04-06
Also published as: DE102004052158A1

Abstract

The invention relates to a multilayered construction body protecting against radiation, shielding against gamma and/or particle radiation from high energy and/or nuclear reactions, used as a wall, bottom or ceiling of a radiation protection chamber. According to the invention, the construction body protecting against radiation comprises two carrier layers, between which at least one or optionally two radiation shielding layer(s) is/are arranged in a sandwich-type structure.The first radiation shielding layer is made of a first shielding material reducing the effect of gamma radiation and/or high energy particle radiation and the optional second radiation shielding layer is made of a neturon-moderating and absorbing material. According to the invention, the first and/or second shielding material is provided in the form of a loose or compacted filling material between the first and second carrier layer. The inventive low-cost construction body protecting against radiation can be produced and dismounted in a quick and easy manner and can be easily recycled.

Description

Multilayer radiation protection building

FIELD OF THE INVENTION The invention relates to a multilayered

Radiation protection structure, in particular for shielding gamma and / or particle radiation from high energy and / or nuclear reactions and for use as a wall, floor or ceiling of a radiation protection chamber.

Background of the invention

High-energy accelerators for particle beams have so far been used mainly in basic research. Other applications, e.g. energy generation is discussed in the context of inertial fusion, where heavy-ion accelerators serve as drivers of nuclear fusion reactions.

Furthermore, the use of particle accelerators in medicine for deep tumor irradiation is about to move from a medical research project to a recognized cure. Dedicated particle irradiation clinics are currently under construction in Heidelberg, Germany (see KD Gross, M.Pavlavic (Editors), Report of the DKFZ, GSI, and FZR (1998)) or will soon be completed in Munich, Germany (see www .rptc.de, Rinecker Proton Therapy Center an institution of PRO-HEALTH AG).

Various ion therapy units are being planned throughout Europe, such as the CNA in Italy, the Medaustron project in Austria or an accelerator at the Karolinska Hospital in Stockholm. The proton therapy system with isocentric gantry has been in operation for several years at the PSI in Villigen in Switzerland.

In all systems, where beam losses or beam deposition occur, there is the technical problem of defining shielding measures in order to reduce the radiation levels outside these areas and, in particular, to maintain them at a level that complies with the requirements (limits) of the respective national radiation protection legislation.

Until now, mainly concrete shields in the form of firmly cast walls and ceilings have been used on accelerator systems and in general in nuclear technology. Alternatively, individual shielding modules, which are assembled as individual parts result in an overall shielding. For special requirements on the shield, in addition to normal concrete with typical densities in the range of 2.3 g / cm ³ , heavy concrete types with corresponding aggregates such as magnetite, limonite or barite concrete with densities of up to 3.6 g / cm ³ can be used (see also DIN 25413). However, as these types of concrete are costly, in practice, normal concrete is used to optimize costs and the results of the screening.

High energy accelerators, when ions are slowed down in matter, produce different secondary radiations through nuclear interactions. If, for example, an ion beam in the range of GeV per nucleon or even higher is used, pion radiation is increasingly generated in the direction of the primary ion beam. This sharply directed pion beam breaks up into muons. Furthermore, increasingly high-energy neutron or photon radiation is generated. This high-energy radiation has a very high range, even in very dense matter such as concrete.

Consequently, at very high particle energies, e.g. for a 30 GeV proton beam stopped in matter, a very long or thick shielding will be installed. Therefore, previously known shields sometimes have very high wall thicknesses in order to be able to effectively shield the radiation.

So if concrete is used as a shielding material, therefore, large quantities of concrete must be processed and poured into corresponding predetermined shapes. This is disadvantageous in several respects.

Such massive concrete shields are namely built by introducing the liquid concrete into a reinforced by iron reinforcements and prefabricated by formwork form. This causes a long construction time in a highly disadvantageous manner, because for very strong shielding the setting and cooling time of the concrete is in the range of up to several months.

In addition, conventional hard-poured and set concrete shades are inflexible and difficult to recycle. Namely, once the concrete shield is completed, it can be changed only very difficult or only with great effort later. The concrete is hardened and the steel reinforcements within the layer make it difficult to change the structure of the shield.

For example, the document DE 103 27 466 A1 discloses a concrete double wall which is filled with in-situ concrete, so that a compact concrete layer is obtained. Although you can the in-situ concrete heavy materials are added to enhance the radiation protection, but these are incorporated into the in-situ concrete, so that the above-mentioned disadvantages of a potted hardened concrete wall are also present. Particularly disadvantageous is the low

Heavy material density in the in-situ concrete, so that the ratio of thickness to shielding further improvement. In general, this is an attempt to cope with the difficulties of a variety of layers, which makes the structure, however, overly complicated. Furthermore, this arrangement seems to be designed only for specific fields of application.

Today, the recycling of raw materials is becoming increasingly important. However, recycling the hardened concrete is almost impossible.

General description of the invention

The invention therefore has the task of a multi-layer radiation protection structure, in particular for the shielding of high-energy gamma and / or

To provide particle radiation from high energy and / or nuclear reactions and for use as a wall, floor or ceiling of a radiation protection chamber, which at least partially meets the above requirements and avoids or at least reduces the disadvantages of known techniques.

In particular, it is an object to provide such a radiation protection structure and a radiation protection chamber, which are quick, inexpensive and inexpensive to produce and build and also dismantle again and their components are good to recycle.

A further object is to provide such a radiation protection construction body which has the lowest possible overall thickness with a high shielding effect. Yet another object is to provide such a radiation protection structure which is relatively flexibly adaptable to changes in the desired radiation shielding characteristic.

The problem is solved in a surprisingly simple way already by the subject-matter of patent claim 1. Advantageous developments of the invention are defined in the subclaims.

According to the invention, a multilayer

Radiation protection structure provided, which in particular for the shielding of gamma and / or particle radiation from high energy and / or nuclear reactions and for use as

Wall, floor or ceiling of a radiation protection chamber is prepared. The radiation protection building or the

Radiation protection device comprises at least a first and second solid support layer, e.g. each a normal concrete slab, and at least a first Strahlungsabschirmschicht on. The first

Radiation shielding layer is arranged between the first and second support layer, such that a sandwich-like structure is formed.

The first radiation shielding layer consists of a

Gamma radiation and / or high-energy particle radiation attenuating first shielding material, which is provided in the operating state of the radiation protection structure as a loose or compacted, ie in particular unbound filling material between the first and second support layer. Thus, the gamma radiation and / or high energy particle radiation attenuating first radiation shielding layer is formed as a first loose or densified filling layer. Here, the first shielding material is arranged as bulk material in the form of granular raw material between the two support layers, wherein the two support layers are retained as two separate layers.

In other words, the first shielding material is preferably not mixed with concrete or other set building material to form a solid layer, but remains, in particular, for the entire duration of the application as an unbound bed, so that at least partially

Functional separation between support and Abschirmschirmfunktion the support layers or Strahlungsabschirmschichten is achieved.

Namely, the first shielding material also fulfills its shielding function against high-energy radiation even in unbound and unprocessed form, but a considerably reduced outlay arises in comparison with the previously known methods.

Advantageously, a longer setting and cooling phase can be dispensed with in the production of the radiation protection structure according to the invention with the heaped-up first radiation shielding layer, so that the overall construction time can be shortened.

Furthermore, the outer shape of the shield can be changed more easily than with solid potted concrete shields. In fact, in the case of the invention, it is only necessary to structurally change the formwork or base layers. These are in the inventive

Structure preferably only a few tens of centimeters thick, eg thinner than 50 centimeters, 40 centimeters, 30 centimeters or 20 centimeters and / or of lesser thickness than the first radiation shielding layer. First, the loose or compacted shielding material or bulk material is removed, subsequently the base layers become rebuilt and then the same bulk material can be re-introduced. This is relatively easy and it is even achieved a double benefit. On the one hand no new expensive shielding material is needed and on the other hand, that removed shielding material must not be disposed of. This is a considerable advantage, especially with radioactive material whose disposal poses considerable problems.

However, the structure according to the invention is also advantageous in the event of final demolition and disposal of the installation after it has been used. Again, the effort can be reduced accordingly by the invention. The support layers and the shielding material or bulk material can be dismantled separately beyond and in particular the latter can be used again for other applications. A laboriously dismantled thickly poured conventional concrete wall is for radiation protection shields in nuclear technology usually no longer usable.

It has proven to be advantageous simple to produce the first and / or second support layer of uniform or homogeneous building material, in particular concrete slabs and to assemble them on site. Although the concrete slabs may possibly be reinforced for stabilization, however, the concrete slabs preferably contain no further heavy material additives and the area between the building material slabs in which the shielding material is poured in may preferably remain devoid of armor since the shielding material has essentially no supporting function. In particular, heavy materials or metals are preferably added to the liquid concrete.

Preferably, the first radiation shielding layer is formed as a spallation layer, so that an effective Radiation shielding high-energy particle radiation is guaranteed.

Likewise for shielding high-energy gamma and / or particle radiation, the first shielding material advantageously contains as main component elements having an atomic number greater than 20, in particular greater than 25, the proportion of elements having an atomic number greater than 20 or 25 at the atomic number first shielding material preferably at least 20 wt .-%, in particular at least 40 wt .-%, 60 wt .-% or 65 wt .-% is.

Furthermore, it is advantageous for the shielding effect if the first shielding material, for example by appropriate selection of material and / or densification, has a density of at least 2 g / cm ³ , in particular at least 3 g / cm ³ , 3.5 g / cm ³ , 4 g / cm ³ or 5 g / cm ³ , because thereby the wall thickness can be reduced.

The first shielding material proposed is, in particular, a material containing metal and / or metal compounds.

It is particularly simple and cost-effective to use metal-containing ore, in particular iron ore, as the first shielding material.

Advantageously, therefore, granular, in particular coarse or fine-grained raw material can be used as a shielding, which comes directly from the dismantling of the deposits and is not or only slightly processed.

The suitable first shielding material may also be based on the so-called tenth-value layer thickness of the candidate Materials are selected. A tenth-value layer thickness is the necessary layer thickness to reduce the original dose rate by a factor of 10.

According to Sullivan, the following values are given for the tenth-value layer thicknesses of high-energy neutron radiation for various materials according to Table 1 (see A.H. Sullivan, A Guide to Radiation and Radioactivity Levels near High Energy Particle Accelerators, Nuclear Technology Publishing, Ashford, Kent (1992)):

Table 1:

Various materials for attenuation of high-energy particle radiation with tenth-layer thicknesses Di _{/ 10} .

Preferably, the first shielding material is selected such that the first radiation shielding layer for high-energy particle radiation, in particular high-energy

Neutron radiation, a Zehntelwertschichtdicke of less than 75 cm, in particular less than 70 cm, smaller than 60 cm or smaller than 50 cm.

A particularly preferred embodiment of the invention has a double-sandwich construction in which two loose or compacted radiation shielding layers, in particular made of different material between two support layers and a partition wall or intermediate layer for the separation of the two Fill layers are provided so that the radiation protection structure has the following layer order:

- first base course,

first radiation shielding material, intermediate layer,

second radiation shielding material,

- second base course.

Such an arrangement can be particularly effectively adapted to the requirements of the shielding of high-energy radiation.

The partition may e.g. also be designed as a foil or a metal sheet.

A surprising finding of the invention is that with a simplification of the construction, a result improved in many respects can be achieved.

The second shielding material comprises or consists of a neutron moderating and / or absorbing material.

For this come especially materials, which as

Main constituent Elements with an atomic number less than 25, in particular less than 20, are considered.

These materials also typically have a lower density than the first shielding material, namely preferably at most 3.5 g / cm ³ , in particular at most 3 g / cm ³ , 2 g / cm ³ or 1.8 g / cm ³ .

As a neutron moderating and / or absorbent material are exemplified the following materials are suitable: Bon _0, Gadoliniuπ \ i _57, gadolinium ^, Cadmiumn ₃ or Lithiumε. It is also possible to use gypsum with an addition of a neutron-absorbing material. Under certain circumstances, it may also be advantageous to use as the second radiation shielding layer a liquid layer, for example of boron dissolved in water.

Particularly preferred, due to its neutron moderating

Effect is a hydrogen-containing or hydrous second shielding material. In particular, gypsum has proven to be suitable because of the bound water content to scatter and absorb generated neutron radiation.

Finally, with a number of radiation protection structures according to the invention, it is possible to build up a radiation protection chamber for a reaction site on a particle accelerator, the radiation protection structures forming walls, floors and / or ceilings of the radiation protection chamber.

Particularly advantageous again is the separation of functions according to the invention between the support function and the radiation shielding function of the respective layers, such that the support layers ensure the statics of the radiation protection structure and the chamber and the first and / or second radiation shielding layer essentially only fulfill a radiation shielding function.

The radiation protection chamber preferably initially has an entry region for a high-energy beam generated by the particle accelerator, which strikes a target at a reaction site in the chamber.

In particular, the radiation protection construction body has an asymmetric layer structure, wherein the first radiation shielding layer on the side facing the target and the second radiation shielding layer are arranged on the side facing away from the target, ie in particular that to the radiation source facing part of the shield of materials with higher atomic number Z, for example, metal or metal ore exists.

It has also been found that under certain circumstances it is sufficient to provide the radiation protection structure in the forward direction with both of the aforementioned radiation shielding layers. In fact, the lateral radiation protection bodies usually require only one layer of the second shielding material. In other words, the radiation protection chamber has, in sections, the first and second radiation shielding layers.

The reason for this arrangement is that high energy hadrons such as e.g. fast neutrons, but also protons, pions and muons essentially in

Forward direction are emitted from the target and experience in the first shielding material core interactions with increased probability and are generated in spallation reactions mostly protons, nuclear fragments and neutrons of lower energy.

These lower energy reaction products are efficiently attenuated in the second radiation suppression layer, as well as laterally and backwardly emitted, lower energy radiation from the target.

However, depending on the radiation protection application, it may also be advantageous to form not only a substantially closed outer cage made of the second shielding material but also an inner cage of the first shielding material.

The chamber nevertheless preferably has an access area for persons, for example in the form of a retractable radiation protection door or a labyrinth-shaped entrance area. Furthermore, provision may be made for using an additional loose or compacted radiation shielding layer made of a material which is obtained when shielding nuclear installations.

The invention thus ensures even under extreme conditions in particular:

1. An effective weakening of all types of radiation (neutrons, photons, pions, muons, protons).

2. The lowest possible activation during operation, or a rapid decay of the generated radioactivity.

3. The possibility of reusing the shielding materials or correspondingly easy disposal of the materials even after a long period of use.

4. A reduced effort in the construction (in this regard, for example, the lack of heat from setting concrete) and the degradation of the shield. This achieves a simplified dismantling compared to the solid concrete structure.

5. A situation under sometimes very high levels of radiation. With a suitable material selection, no or only a small chemical change of the shielding materials occurs.

6. Compliance with the protective provisions, in particular fire safety regulations, i. including resistance to thermal effects and exposure to hazardous substances such as Lyes and acids as well as low release of pollutants.

7. The possibility of modifying an arrangement of radiation protection structures to changed spatial requirements, for example by adding new irradiation areas on an accelerator. 8. The avoidance of gaps between the shielding walls through which the radiation could be transported.

9. The possibility of greater use of industrially prefabricated components. 10. A reduction of the energy expenditure for the construction and the dismantling of the shielding.

11. A reduction in construction and dismantling times.

In the following the invention will be explained in more detail by means of embodiments and with reference to the drawings, wherein the same and similar elements are provided in part with the same reference numerals and the features of the various embodiments can be combined.

Brief description of the figures

Show it:

1 shows a cross section through an exemplary embodiment of the multilayer radiation protection structure I ₁ according to the invention

2 shows a schematic horizontal section through a first exemplary embodiment of the radiation protection chamber 50 according to the invention,

FIG. 3 shows a resulting dose distribution in the form of a radiation transport program. FIG

Isodosislinien for the radiation protection chamber 50 of FIG. 2, Fig. 4 is a schematic horizontal section through a second embodiment of the radiation protection chamber 50 according to the invention with a therapy space for

5 shows a schematic horizontal section through a third exemplary embodiment of the radiation protection chamber 50 according to the invention with a therapy station for ion irradiation. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows an exemplary structure of a radiation protection building 1 according to the invention. The radiation protection structure has as support layers an inner and an outer wall 2, 4 consisting of concrete, a first metal-containing Strahlungsabschirmschicht 6 consisting of iron ore and a second Strahlungsabschirmschicht 8 consisting of gypsum (CaSO ₄ -2H ₂ O). The gypsum layer 8 has a high water content. The iron ore 6 and / or the gypsum 8 are installed as shielding materials in each case in bulk or compacted during installation in order to achieve a higher shielding effect. However, the radiation shielding or filling layers 6, 8 thus produced remain permanently unbonded and, in particular, are not mixed with concrete. The iron ore bed 6 and the gypsum bed 8 are separated by an intermediate wall 10. Consequently, in this embodiment, the radiation protection building body 1 consists, in particular precisely, of five layers, namely, in the order from the inside to the outside, of the first (concrete) supporting layer 2, the first (iron ore) radiation shielding layer 6, the (concrete) Partition wall 10, the second (gypsum) Strahlungsabschirmschicht 8 and the second (concrete) support layer. 2

The iron ore used varies in composition according to its origin. Examples are given in Table 2.

Table 2:

Main constituents of iron ores from different deposits in%: 1 - Kiruna B (Sweden),

2 - Itabira CBPO (Brazil),

3 - Svappavaara D (Sweden),

4 - Carol Lake Pellets (Canada) and

5 - Sydvaranger Conc. (Norway)

(from Ullmann's Encyclopedia of Industrial Chemistry, 4 Edition, 1975, Verlag Chemie, Weinheim / Bergstrasse).

Fig. 1 shows the arrangement with the invention

Separation of functions of the layers, in those on the one hand ensure the statics of Strahlenschutzbaukörpers 1, namely at least the inner and outer walls as support layers 2, 4, and those on the other hand, the actual shielding effect, namely the Strahlenabschirmschichten 6, 8 from

Filling or shielding materials. The partition or partition wall 10 may also contribute to the static, but does not have to. The stability of the arrangement can be further increased by extending an anchor, in particular tie rod 12 through the complete inner and outer walls 2, 4 and is secured to the respective outer side. Thus, according to the invention a multi-layer sandwich arrangement with at least two different types of shielding materials 6, 8 provided.

By separating modules or layers having a static function (support layers) 2, 4 from those having a substantially pure shielding function (radiation shielding layers) 6, 8, a better adaptation of the shielding to different types of radiation and energy ranges is made possible.

For high-energy radiation 16 like her

High-energy accelerators occurs, it has proved to be useful, the first radiation-shielding layer 6 of metal-containing ore and the second radiation shielding layer 8 of a hydrous filler such. To build plaster. Other variations are conceivable here, such as e.g. to introduce the introduction of additional material types in additional layers. The order of the layers 4, 8 is preferably asymmetrical and in particular chosen so that the radiation source or incident radiation out (in the left figure), usually secondary radiation 16, the metal-containing layer 6 and then - separated from the intermediate wall 10 - hydrogen-containing or hydrous layer 8 for moderating and absorbing the generated neutron radiation.

Accordingly, in particular the material 6 with the highest atomic number Z, and the side facing away from the radiation source, the material 8 with a lower Z are used. In the choice of materials, the type and energy distribution of the radiation field of the secondary radiation 16 is also taken into account. It should also be taken into account that during transport of the radiation by matter further new radiation is generated. So the transport of neutron radiation is always with the generation of Gamma radiation associated (n, γ or n, n'γ processes).

While neutron radiation is weakened mainly by hydrogen-containing substances, the weakening of gamma radiation is ensured above all by high-Z materials. So the right choice of materials is also a compromise between different requirements, so that material mixtures can be advantageous.

In the context of the present invention further optimizations can be made by an appropriate selection of the shielding materials, while in standard concrete shields often the material composition is determined by the construction companies themselves, depending on the source of supply of the raw materials. Even a subsequent change of the radiation fields with the result that the shielding is to be changed, is better with the invention possible than with a solid concrete shield, which typically would have to be completely replaced.

For the construction of the first two support layers 2, 4 and where necessary, the intermediate layer 10 is built around the reaction area around and subsequently the two Strahlungsabschirmschichten 6, 8 am

Place of use by filling or pouring the loose filling material, which consists of the respective shielding, made in the spaces between the support layers. Advantageously, untreated bulk material β, 8 can be used as shielding material, eg iron ore or gypsum. This achieves a reduction in the processing cost of the starting materials. It is also advantageous that the radiation protection structure according to the invention immediately can be used after filling and possibly compacting the filling material. The dismantling takes place in the reverse order. Therefore, the radiation protection structure according to the invention is simple in construction and dismantling, as well as flexible with respect to a later conversion.- In particular, the subsequent disposal or reuse of the shielding materials 6, 8 is considerably simplified.

The shielding effect achieved depends, among other things, on how highly compressed the filler material is incorporated into the shielding. The achievable density, in turn, depends on the size distribution of the materials to be incorporated. Thus, with a fine-grained degraded material, a higher built-in density can be achieved, as with a coarse grained

Material. Of particular importance for the design of the radiation protection structure 1 is a predetermined minimum density in all areas of the shield. It is therefore of advantage if the granularity of the raw shielding material, in this example ore and natural gypsum, has a certain minimum fineness in order to ensure a sufficiently high compaction during installation.

In particular, the necessary space for the realization of the shield is not or not significantly higher than conventional concrete shields, or may even be smaller if the bulk material 6, 8 sufficiently compacted or tightly compressed in the shields is installed. This is particularly advantageous in the clinical area, where such plants are usually built in densely populated areas with little spatial expansion possibilities.

The following examples show possible uses of the radiation protection structure according to the invention. Embodiment 1

Radiation protection chamber (so-called Cave) for nuclear collisions

As an example of a shielding with iron ore and gypsum as Abschirrtimassen 6, 8 the planned CBM cave (Condensed Baryonic Matter) of the FAIR project was developed. This is a building that is constructed on all sides from the radiation protection structures and in which experiments for nuclear collisions occur at over 30 GeV per nucleon.

In Fig. 2, the CBM cave with gold ions as primary rays 14 is shown. The ions enter the cave through an entrance region 34 and strike a target 18 and their reaction products are measured by a detector (not shown). At the same time secondary radiation 16 is generated, which is to be shielded. Access to the cave via an entrance labyrinth 30, which is located at the edge of the entrance wall.

In this example, a gold beam of intensity 10 ⁹ ions / sec and energy 30 GeV per nucleon was deposited in a thin iron piece as target 18 (1% interaction rate). The secondary radiation emanating from the target 18 is weakened by the building to a level of less than 0.5 μSv / h. This is achieved by constructing layers in the order concrete 2, iron ore 6, plaster 8 and concrete 4 from the inside to the outside (see Fig. 2, wherein the partition wall 10 in this

Presentation is omitted for clarity). It is advantageous that the two loose or compacted Strahlungsabschirmschichten, in this example consisting of ore 6 or gypsum 8, in particular both, even at corners 20 at which the walls 1 collide, at least are partially guided around closed, so that even in these corner regions 20 a sufficient and compared to a blunt juxtaposition of two sandwich walls improved shielding effect is achieved.

Furthermore, it can be seen in FIG. 2 that a closed inner cage made of iron ore 6 and a closed outer cage made of gypsum 8 are provided for this cave. However, the thicknesses of the radiation shielding layers 6, 8 are larger in the forward direction than laterally or rearwardly. This is adapted to the radiation characteristic of the secondary radiation. Incidentally, laterally, the gypsum layer 8 is thicker than the ore layer 6.

The resulting dose distribution 22 was compared with a

Radiation transport program determined and is shown in Fig. 3 in the form of Isodosislinien. The innermost line 24 corresponds to a dose of 10 ⁶ μSv / h, the outermost line 26 of 10 ^"1 μSv / h, between which there are successive isodose lines of 10 ⁵ μSv / h, 10 ⁴ ' ⁵ μSv / h, 10 ⁴ μSv / h, 10 ³ μSv / h, 10 ² μSv / h, 10 ¹ μSv / h and 10 ° μSv / h The target dose rate of 0.5 μSv / h or less is here with an iron ore of density 3.5 g / cm ³ and gypsum the density of 1.8 g / cm ³ , surrounded by normal concrete (possibly armored, but without further heavy or iron additives to substantially change the shielding effect) achieved.

It can be provided to arrange in the forward direction outside the CBM cave a beam destroyer (so-called beamdump), which in particular has the same layer structure as the radiation protection wall according to the invention and preferably directly adjoins it. This is advantageous in particular to further attenuate the resulting residual radiation in the forward direction. Exemplary embodiments 2 and 3:

Therapy cave for treatment with proton or heavy ion beams

In recent years, the treatment of specific tumor diseases with proton or ion beams has become a very effective method. Most plants worldwide are operated or currently under construction in Japan. In Europe, systems for proton therapy are usually with

Cyclotrons and built for carbon therapy with synchrotrons. For proton beams 14, energies up to about 230 MeV are used and alternatively for carbon ions 14 to about 430 MeV per nucleon are used. Accordingly, the therapy treatment rooms in which the ions are stopped in the tissue must also be strongly shielded.

The invention has now been applied to the design of two therapy caves 50. In Fig. 4 and 5, these Caves 50 are in the multilayer sandwich technique according to the invention with

Iron ore bulk material or other (heavy) metal-containing filling material as a first Strahlungsabschirmschicht 6 realized in the forward beam direction and in the second Strahlungsabschirmschicht 8 with gypsum. Alternatively, the filling compound 8 from another hydrogen-containing

Material possibly formed with an addition of a neutron absorbing material. The inner, outer and intermediate walls 2, 4, 10 essentially serve only as support layers for shuttering the unbonded filling material 6, 8 or the loose or compacted filling layers.

FIG. 4 relates to a cave 50 with retractable shielding door 28, FIG. 5 on a cave 50 with an access labyrinth 30. The iron ore 6 has the function of converting in particular the high-energy neutron radiation into nuclear reactions for the emission of neutrons, protons and nuclear fragments of smaller energy, which are moderated and / or absorbed in the iron ore 6 itself or in the subsequent gypsum layer 8. The iron ore radiation shielding layer 6 thus forms a spallation layer (possibly with moderation function). The gypsum radiation shielding layer 8 forms a neutron moderating and / or absorbing layer.

Unlike the cave for core collisions according to FIG. 2, in the cavities shown in FIGS. 4 and 5, the ore layer 6 is required only in the forward direction, since high-energy radiation is generated mainly in the forward direction. The ore layer 6 and associated support layers form a generally curved C- or U-shaped arrangement to enhance the high-energy secondary radiation 16 emitted by the target 18 or the therapy site 32 (the patient to be treated forms the target) for proton or ion irradiation shield. Transverse to the primary beam 14, here an ion beam, only radiation shielding layers 8 made of gypsum, which together define a radiation protection cage are provided.

Other exemplary applications

The use of the invention is applicable to many plant areas, in particular the FAIR project at the Gesellschaft für Schwerionenforschung mbH. These are: 1. SIS 100/300, in particular its beam guides to the super fragment separator, anti-proton production target, CBM caves

2. Super FRS 3. Anti-proton production area

4th Cave plasma physics

5. Storage rings.

Other areas of application are principally in all high-energy accelerator systems, in particular in the currently planned therapy facilities for proton and ion beams in Germany and abroad. There the invention can find application for therapy caves in proton and heavy ion therapy clinics.

However, according to the inventors, the invention can also be applied to high-dose irradiation systems with smaller beam energies. Conventional X-ray therapy systems can be realized with this shielding technique.

The shield according to the invention is particularly suitable for electron linear accelerators, betatrons or microtron, Kobalt6o ~ or Cäsiumi3 ₇ -Bestrahlungsanlagen or with appropriate radionuclides. Other exemplary applications are accelerators for generating

Bremsstrahlung, e.g. for materials research. Moreover, the invention can be used for accelerators or radioactive sources for polymer irradiation. Another field of application are cyclotrons and electron synchrotrons.

The present invention comprises, according to a particularly preferred embodiment, in summary, three main components: 1. A multilayer sandwich arrangement, wherein the base layers or structuring elements that guarantee the statics of the overall shielding can be, for example, concrete precast elements.

2. Different types of shielding materials adapted to the type and energy spectrum of the radiation produced.

3. Use of granular, in particular coarse or fine-grained raw material as shielding material, which originates from the direct mining of the deposits and possibly only slightly processed, e.g. is ground.

It will be apparent to those skilled in the art that the above-described embodiments are to be understood as illustrative, and that the invention is not limited thereto, but that it can be varied in many ways without departing from the spirit of the invention. It will also be appreciated that features of various embodiments may be combined.

Claims

claims

1. Multilayer radiation protection building (1), in particular for shielding gamma and / or particle radiation (16) from high energy and / or nuclear reactions and to

Use as a wall, floor or ceiling one

Radiation protection chamber (50), wherein the Strahlenschutzbaukörper (1) at least a first and second solid support layer (2, 4) and at least a first Strahlungsabschirmschicht (6), wherein the first Strahlungsabschirmschicht (6) between the first and second support layer (2, 4 ) is arranged such that a sandwich-like structure is formed, wherein the first radiation shielding layer of a

Gamma radiation and / or high-energy particle radiation attenuating first shielding material (6) is formed and wherein in the operating state of the radiation protection body

(1) the first shielding material as loose or compacted

Filling material is provided between the first and second support layer, so that the first

Radiation shielding layer (6) is formed as a first loose or compacted filling layer.

2. Radiation protection building body (1) according to claim 1, characterized in that the first shielding material is not mixed with concrete (2, 4) or another hardened building material to form a solid layer.

3. Radiation protection building body (1) according to one of the preceding claims, characterized in that at least the first and second support layer (2, 4) uniform or homogeneous building material panels, in particular concrete slabs exists and the area (6, 8) between the building material plates is substantially irrigation.

4. Radiation protection building body (1) according to one of the preceding claims, characterized in that the first Strahlungsabschirmschicht (6) is formed as Spallationsschicht.

5. Radiation protection building (1) according to one of the preceding claims, characterized in that the first shielding material contains as main component elements having an atomic number greater than 20.

6. Radiation protection building body (1) according to claim 5, characterized in that the proportion of elements having an atomic number greater than 20 on the first shielding material at least

20 wt .-% is.

7. Radiation protection building body (1) according to any one of the preceding claims, characterized in that the first shielding material has a density of at least 3 g / cm ³ .

8. Radiation protection construction body (1) according to one of the preceding claims, characterized in that the first shielding material contains metal or metal compounds.

9. Radiation protection building body (1) according to one of the preceding claims, characterized in that the first shielding material contains a metal-containing ore.

10. radiation protection building (1) according to one of the preceding claims, characterized in that the first shielding material contains iron ore.

11. Radiation protection building (1) according to one of the preceding claims, characterized in that the first shielding material is selected such that the first Strahlungsabschirmschicht for high-energy particle radiation has a tenthary layer thickness of less than 75 cm.

12. Radiation protection building (1) according to any one of the preceding claims, characterized in that a second Strahlungsabschirmschicht (8) between the first and second support layer is arranged, wherein the second Strahlungsabschirmschicht (8) is formed of a different from the first shielding second shielding material.

13. Radiation protection building body (1) according to any one of the preceding claims, characterized in that in the operating state, the second shielding material as loose or compacted filling material between the first and second support layer (2, 4) is provided, so that the second Strahlungsabschirmschicht (8) as a second loose or compacted filling layer is formed.

14 radiation protection construction body (1) according to any one of the preceding claims, characterized in that the second shielding material is a neutron moderating and absorbing material.

15. Radiation protection building body (1) according to one of the preceding claims, characterized in that the second shielding material contains as main constituent elements with an atomic number less than 25.

16. Radiation protection building (1) according to one of the preceding claims, characterized in that the second shielding material has a density of at most 3.5 g / cm ³ .

17. radiation protection building (1) according to one of the preceding claims, characterized in that the second shielding material is a hydrogen-containing material.

18. Radiation protection building body (1) according to one of the preceding claims, characterized in that the second shielding material contains gypsum.

19. Radiation protection construction body (1) according to one of the preceding claims, characterized in that a separation of functions between the support function and the Strahlungsabschirmfunktion the respective layers is provided, such that the support layers (2, 4) ensure the statics of the radiation protection structure (1) and the first and second radiation shielding layers (6, 8) substantially only satisfy a radiation shielding function.

20. Radiation protection building body (1) according to any one of the preceding claims, characterized in that between the first and second filling layer (6, 8), a solid partition wall (10) is provided.

21. Radiation protection building (1) according to one of the preceding claims, characterized in that a further outer radiation shielding of loose or compacted earth is provided.

22 radiation protection chamber for a reaction space on a particle accelerator, constructed from a plurality of radiation protection structures (1) according to any one of the preceding claims, wherein the radiation protection building walls, floor and / or ceiling of the radiation protection chamber.

23 radiation protection chamber (50) according to claim 22, characterized in that an inlet region for a generated by the particle accelerator high-energy beam (14) is provided and the high-energy beam to a target (18) in the interior of the radiation protection chamber (50), wherein a Strahlenschutzbaukörper ( 1) in the area of

Forward direction of the high energy beam (14) comprises a first radiation shielding layer of the first shielding material (β) and a second radiation shielding layer of the second shielding material (8), the first radiation shielding layer (6) facing on the target (18) and the second radiation shielding layer (14) 8) is arranged on the high-energy beam (14) facing away from the Strahlenschutzbauköpers (1).

24. Radiation protection chamber according to claim 23, characterized in that all the radiation protection structures each comprise a first radiation shielding layer of the first shielding material and a respective second radiation shielding layer of the second shielding material, wherein the first

Radiation shielding layer on the side facing the target and the second Strahlungsabschirmschicht is arranged on the side facing away from the target side of the Strahlenschutzbauköpers, such that an inner cage of the first and an outer cage of the second Abschirnαmaterial is formed.

25. Radiation protection chamber according to claim 23, characterized in that at least some of the other radiation protection structures each have only one radiation shielding layer of the second shielding material, such that an all-round cage is formed at least from the second shielding material.

26. A radiation protection chamber according to any one of the preceding claims, further comprising a retractable shield door (28) or a labyrinthine passenger entrance area (30).