ar

einrn, Snne,

e catheuitther

the suform of radiation to our planet. This energyby nuclear fusion reactions. Thus, for many

cant coweverimporte of thto undure to

of such complex technology in its early stage. This informationhelps to take educated decisions for the technologys furtherdevelopment and to better justify to the public the substantialnancial investment in research and development.

Evaluation of indirect economic and industrial effects of otherlong-term public research and technology programs has shownthat industry is able to benet from public R&D activities under

nowadays used in a wide variety of commercial applications [18].Nevertheless, spillover effects are difcult to identify and account for[19]. The disadvantage of these previous approaches is that spinoffsand spillovers were only identied if they were obviously related tothe complex technology while technologies not directly linked wereleft undetected and unconsidered.

Amore comprehensive way of identifying spillover technologiesis the analysis of patent literature. However, such an approach willonly help to identify the technologies per se that stem from* Corresponding author. Tel.: 41 (0)31 377 73 68; fax: 41 (0)31 377 79 32.

Contents lists available at SciVerse ScienceDirect

t

lse

World Patent Information 34 (2012) 271e278E-mail address: heinz.mueller@ipi.ch (H. Mueller).degrees for getting the fusion reaction going and to produce anenergy gain by overcompensating the energy needed to maintainand control nuclear fusion.

The way to such a benign and almost inexhaustible energysource is a prime example for the cumbersome development ofa complex technology, which requires signicant expenses inresearch and development over a long period. Unsurprisingly,decision makers are interested in assessing the economic benets

cialization and patent outcome data to the NAICS coding. Such anapproach has been applied to identify knowledge spillovers ingeneral in Europe, but this work shows the knowledge ow betweencountries and regions rather than between technology areas [9].

In the past, spinoffs and spillovers were identied in differenttechnological areas such as space technologies [10e12], high energyphysics [13] as well as in fusion technology [14e17]. Plasma andother technologies developed in part by nuclear fusion research area sun on earth, to name a few, arehot dense plasma, to keep temperathas been believed to make a signienergy needs of tomorrow [1e5]. Hoscientic and engineering progress,still need to be overcome [6]. Som0172-2190/$ e see front matter 2012 Elsevier Ltd.http://dx.doi.org/10.1016/j.wpi.2012.06.001is produced in the sundecades, nuclear fusionntribution to meet the, despite the impressiveant technical obstaclese challenges to createerstand and control thea few hundred million

overs are manifold and are usually based on economics models [7].However, a prerequisite for applying and testing these models isthe identication of existing spillovers from the complex tech-nology under investigation.

A more recent economic approach to identify technology spill-overs used the North American Industry Classication (NAICS) codesin a specic advanced technology program [8]. The conclusion of theauthors was that future work should focus on matching commer-A shear endless energy source is n, sending its energy in ists alike. Approaches to measure the benet of spinoffs and spill-fossil fuel prices and supply, accelerated exploitation of naturalresources, and ecological concerns.

Investigating and better understanding spinoff effects isimportant and attractive for economics and management special-Spillover benets from controlled nucle

Peter Bruns a, Minh Quang Tran b, Daniel Kunz a, Ha Swiss Federal Institute of Intellectual Property, Stauffacherstrasse 65/59g, CH-3003 BebCentre de Recherches en Physique des Plasmas, Ecole Polytechnique Fdrale de Lausa

Keywords:Nuclear fusionSpilloversSpinoffsPatent statistics

a b s t r a c t

The patenting activity in themerging technology as aallows to track not only ta technology that is not qapplicable inventions to o

1. Introduction

The search for alternatives to existing energy technologies suchas nuclear power, hydroelectric power and the combustion of fossilfuels has become more and more important in the light of volatile

World Paten

journal homepage: www.eAll rights reserved.fusion technology e A patent analysis

z Mueller a,*, Christian Soltmann a

witzerlandAssociation Euratom-Confdration Suisse, Station 13, CH-1015 Lausanne, Switzerland

eld of controlled nuclear fusion was investigated to assess the role of thisalyst for inventions in other technological areas. Patent statistical dataevolution of a technology, but also to analyze cross-fertilizing effects ofe ready for implementation. Spillovers from nuclear fusion research fortechnological areas can be identied.

2012 Elsevier Ltd. All rights reserved.

these programs. Spinoffs and spillovers of knowledge and tech-nology can generally be found in all stages of the long-termprograms. Some authors are in fact very optimistic regarding theexistence and the importance of spinoffs from for example spaceresearch, another complex technology.

Information

vier .com/locate/worpat in

The technical contentof the retrieveddocumentswas checkedbyrandomly selecting, reading and evaluating documents individuallyto ensure that they belong to the eld of controlled nuclear fusion.Table 3 summarizes the quality of the data searches. Clearly, using

Table 1International patent classication codes and European classication codes for theidentication of patent documents relating to nuclear fusion.a

Code Description

G21B1/00 (2006.01) Thermonuclear fusion reactorsH05H1/02 (2006.01) Generating plasma; handling plasma

US patent classication code used to identify patent documents relating tonuclear fusion

376/100 Nuclear fusion

Documents having the following European classication code were excluded

Table 2IPC and European classication codes relating to biological cell fusion excluded fromkeyword searches for patent documents relating to nuclear fusion.a

Code Description

A01K (2006.01) Animal husbandry; care of birds, shes, insects;shing; rearing or breeding animals, not otherwiseprovided for; new breeds of animals

C12N (2006.01) Micro-organisms or enzymes; compositions thereof;propagating, preserving, or maintainingmicro-organisms; mutation or genetic engineering;culture media

Information 34 (2012) 271e278complex, large and mostly governmentally funded technologyprograms and does not take into account the social and economicreturns. Nevertheless, since patent data is well structured, orga-nized and indexed, including extensive and detailed classicationof technological areas, the patent-based approach may be a goodbasis for further analysis: Patent analysis at large allows accurateillustration of the activities of applied research, is an excellent toolto monitor such activities and to depict trends in the highlycomplex and interdisciplinary eld of nuclear fusion technology.Statistical and text mining analysis of published patent documentsin the concerned technology eld can help to identify spillovers.Applying such an approach facilitates the identication of tech-nologies previously unknown to stem from the eld of nuclearfusion. An earlier approach using patent data to identify spilloverswas applied in the past to the eld of biotechnology, in particularrecombinant DNA (rDNA) technology [20]. This work attempted toassess the efcacy of various measures of knowledge diffusion,comparing patent citations, publications citations, and licensingdata. Patent data was used by identifying the three core rDNApatents issued by the USPTO and analyzing the patent documentsthat cite one of these three documents. This approach thereforedepended on the identication of a few basic patents in a well-dened technology area. By the same token, the work relied onthe availability and reliability of all these data in a very specic case.

In this paper, we use a broader approach and show that byanalyzing larger sets of patent data, spillovers and spinoffs fromnuclear fusion research can indeed be identied, i.e. a technologythat has not as yet been shown to be directly applicable tocommercialization. In general, such an approach can be used forfurther evaluation of the economic impact of long range research incomplex technology areas.

2. Methods

The term spillover can be dened as any positive externalitythat results from purposeful investment in technological innova-tion and development [21]. For this paper, spillover describeseconomic or social payoffs from a technology that is not yet readyby itself to generate a return on investment, i.e. mostly basicresearch such as nuclear fusion research. Furthermore, spilloverscan manifest in various, very often intangible forms, and for thatreason are extremely difcult to measure in monetary values [15].Approaches to identify the economic impact of spillovers havealready been applied to, for example, high energy physics [22].Spillover effects are often very signicant for large consortiaprojects based on governmental funding. In this study, spillovertechnologies are identied through forward citation analysis astechnologies not directly belonging to the patent classes of nuclearfusion (intersectorial spillovers), but being related to this eld.Intrasectorial spillovers, i.e. spillovers within the technologicalcore area of the conducted research, might also be important forthe full understanding of the economic impact of researchprograms. However, such spillovers are not identied with themethodology used in this paper.

The term spinoff describes, as often dened in the literature, anindependent company created from an existing part of anothercompany or a governmental unit, such as a university, by trans-ferring the know-how of a specic technology or invention fromthe original entity to the new company. In this work, spillovers andspinoffs are not distinguished.

Patent data does not take into account the process that leads toa technology advance, i.e. whether it is a spillover or a spinoff, butcan serve as a basis for the identication of technology benetsstemming from large basic research programs. The methodology

P. Bruns et al. / World Patent272used to identify such spillovers and spinoffs is described below.2.1. The data set

The basic set of patent documents for the study was compiledusing combinations of patent classication codes, keywords, thetechnical content of documents and bibliographic data of theEuropean Patent Ofce database EPODOC. The patent classicationcodes used to identify patent documents relating to nuclear fusionare given in Table 1. The keywords used were: tokamak, stellerator,nuclear fusion, fusor (an apparatus that is used to create fusion),thermonuclear fusion, inertial fusion or fusion reaction and inertialconnement. The keywords were used with different truncationsto include different spellings and the plural forms for searches inabstract and full-text data bases. Besides English, queries were alsocarried out in German and French. The searches were restricted todocuments published earlier than April 2010. The searches wereperformed using either a combination of keywords and patentclassication codes given in Table 1 or by using keywords alone.Some obvious keywords such as laser fusion were used in a rstattempt but had to be omitted because searches with thesekeywords resulted in the retrieval of too many non-relevantdocuments, e.g. by retrieving mostly documents related to weld-ing of plastics. Documents classied as belonging to the eld of coldfusion were excluded from the data set used for further analysis(Table 1). Since nuclear fusion occurs in many documents relatedto biological cell fusion, the patent classication codes described inTable 2 were also excluded when using keywords for the searches.

The statistical analysis of all applicants of retrieved documentsrevealed companies inactive in nuclear fusion technologies, e.g.companies only active in the pharmaceutical or imaging areas.Patents from these applicants were subtracted from the basic set ofpatent documents to further improve the percentage of relevantdocuments in the retrieved data set.

from the searches based on patent classication codesG21B3/00 (2006.01) Low-temperature nuclear fusion reactors,

e.g. alleged cold fusion reactors

a Subcodes of the indicated codes were also used.a Subcodes of the indicated codes were also excluded.

patent classes alone searches result in averydistinct identicationofdocuments belonging to the nuclear fusion eld. More than 11,000documents were found using patent classication codes alone. Anadditional approximately 7500 documents were identied bykeywords, amounting to a total of approximately 18,500documents.95per centof thedocuments retrievedbypatent classication codesalone were indeed related to nuclear fusion whereas the rate ofrelevant documents was only 72.5 per cent when combining

indicative of the place where the invention occurred. The share ofpriority documents relating to a specic country or region mayaccordingly be considered indicative of a countrys/regions inno-vation activity in a technical eld and may help to identify whichcountries or regions aremost active in developing new solutions forthe nuclear fusion eld.

Combining patent class searches with keyword searches resul-ted in a higher percentage of retrieved documents not directly

Table 3Evaluation of documents retrieved using randomized samples with a sample size of 100.

% of Documents relatedto nuclear fusion

% of Retrieved non-fusiondocuments

Number of documentsevaluated

Documents retrieved using patent classication only 95 5 100Documents retrieved using patent classication or keywords 72.5 27.5 400Documents with oldest priority date before 1991 retrieved

using patent classication or keywords76 24 99

Documents with oldest priority date of 1991 and newerretrieved using patent classication or keywords

57 43 99

P. Bruns et al. / World Patent Information 34 (2012) 271e278 273keyword searches and patent class searches. However, even thoughpatent classication codes yielded a very high search precision,relying on patent classication codes alone would have left uncon-sideredmanydocuments about nuclear fusion-related technologies.Nevertheless, including the documents found by keyword searchesinto the set of documents found by patent class searches increasedthe percentage of non-fusion-related documents from 5% to 27.5%.Therefore, most of the following statistics were performed on thecomplete set of the approximately 18,500 documents.

2.2. Statistical analysis

Statistical analyses of the basic set of patent documents wereperformed to map the chronological development of patentingactivity in the eld of nuclear fusion and to provide the basis fora comparison between patenting activity and expenditure inresearch and development in the eld. In addition, patent land-scape maps were created to identify emerging new technologysectors, and a forward citation analysis was performed to revealspillover from the nuclear fusion domain into other technical eldsand its diversication.

The patent documents were grouped according to the prioritycountry/region. The country or region where the rst patentapplication relating to an invention was led may be consideredFig. 1. Number of patent documents relating to nuclear fusion per oldest priority year. A dG21B, H05H1/02 or 376/100 (core technologies), excluding those documents having the Euralleged cold fusion reactors), and patent documents which could be retrieved by keywordelds in the respective period was added (right axis).belonging to the eld of nuclear fusion technologies than usingkeywords alone (Table 3). Combining these two types of searchesresulted in a 65% increase of the total number of retrieved docu-ments (not shown) indicating that using of patent classes alone willnot cover the whole technological eld. However, the rate ofdocuments not belonging to the nuclear fusion eld also increasedfrom 5% to 27.5%. Interestingly, the set of documents with prioritydates before 1991 shows a signicant lower percentage of docu-ments not belonging to the nuclear fusion eld than the set ofdocuments having priority dates after 1991. This might indicatethat the research in nuclear fusion technologies during the past 20years diversied into other elds and thus these documents mightrepresent at least in part the technology spillovers. On the otherhand, the observed effect could also be caused by the emergence ofplasma coating applications and similar techniques not related tofusion research. To overcome this problem, the documents identi-ed at the end of the statistical analysis to describe possible spill-over technologies might have to be evaluated one by one.

The number of patent publications over time is strongly consid-ered to be an indication of applied research activities. Figure 1 (sumof PCT, Europe, Japan, SU/RU and USA) shows the number of patentdocuments relating to nuclear fusion versus priority year of thepublications. Patenting activity in controlled fusion technologyincreases steeply between 1970 and 1985 and much moreistinction was made between patent documents having the patent classication codesopean patent classication code G21B3 (low-temperature nuclear fusion reactors, e.g.s only. For comparison, the evolution of published patent document in all technology

pronounced than the patenting activity of all technology eldscombined (black curve, Fig. 1). After 1990, the patenting activitysomewhat leveled off without any further signicant increase. Thisgure likely reects the historic developments in theeld of nuclearfusion. First patent publications were found dating from the begin-

increase in patent documents is observed between 1955 and 1960that might be associated with research on the hydrogen bomb. Thepatenting activity in controlled fusion technology increased steeplyover the next 15 years. The second peak in patenting activitybetween the 1980s to the early 1990s might be related to the Japa-

Fig. 2. Number of patent documents per oldest priority year: the number of patent documents claiming priority at WIPO (WO), in Europe (AT, BE, CH, DD, DE, DK, EP, ES, FI, FR, GB,GR, IT, LU, NL, NO, SE), Japan (JP), Soviet Union/Russia (SU/RU) and the United States (US) were determined and plotted, reecting signicant changes in patenting activity over time.

19

P. Bruns et al. / World Patent Information 34 (2012) 271e278274ning of the 20th century but for more than 50 years no signicantcontribution to the concept of nuclear fusion technology was seen.Research in nuclear fusion began in the early 1940s for militarypurposes as a side project of the Manhattan Project, but withoutsignicant progress until 1952. Civilian research in controllednuclear fusion started in the 1950s, and continues to this day. A rst

Table 4Patent applicants active in the eld of nuclear fusion (key players).

Patent applicant 1950e1970 1971e

Hitachi 3 430

Tokyo Shibaura/Toshiba 6 227Japan Atomic Energy Research Institute 112Mitsubishi 2 130US Energy 2 160Commissariat Energie Atomique 82 19Atomic Energy Commission 169 39University of CaliforniaKawasaki 0 8Siemens 60 26Euratom 14 37KMS Fusion 101Kobe Steel 5Ishikawajima Harima Heavy Ind.Westinghouse Electric 11 38Sumitomo Electric Industries 3Atomic Energy Authority 83 1Texas Gas Transmission 82Matsushita Electric Ind. 5Kernforschungszentrum Karlsruhe 8Nippon SteelMax Planck Gesellschaft 4 7General Electric 10 19Agency Ind. Science Techn 2 8Impulse DevicesApricotUS Army 11Fujikura 10BBC 15 11NGK InsulatorsCentre National De La Recherche Scientique 1 1nese tokamaks JT60 and JT60-U.In Fig. 2, the patenting activities in Europe, Japan, the Soviet

Union/Russia and the United States are distinguished. The countriesof the patent assignees are plotted versus oldest priority year of thepatent documents. Clearly, Japanese assignees led the highestnumber of patent applications, especially between 1978 and 1990.

80 1981e1990 1991e2000 From 2001 Total

803 321 79 1636

884 342 65 1524296 292 61 761417 171 39 759153 10 2 32773 47 74 295

20817 44 80 14161 43 10 12215 10 6 11730 30 1115 106

36 26 37 10443 40 17 10042 3 1 9549 38 2 922 86

8222 25 17 6952 6 6629 24 11 6437 7 7 6212 6 11 5823 25 58

24 33 5750 508 28 47

27 5 5 4721 472 31 12 45

31 3 9 45

There is about equal patenting activity in Europe and the UnitedStates and much less activity in the Soviet Union/Russia.

Furthermore, the set of patent documents was analyzed toidentify the main players in the nuclear fusion eld. Hitachi seemsto have been the most active company in the eld of nuclearfusion research and development with over 1600 patent docu-ments followed by Tokyo Shibaura (Toshiba), with more than1500, the Japan Atomic Energy Research Institute with about 800,Mitsubishi with about 750, and as the rst non-Japaneseassignees, the United States Department of Energy with about330 and the Commissariat dEnergie Atomique (France) with about300 patent documents (Table 4). Thus, Table 4 also underlines thendings from Fig. 1.

3. Results and discussion

One crucial nding of our analysis is that the most important

per cent) and particle physics (6 per cent) (Table 5). The rst twotechnologies are important in the construction of large fusiondevices and hence new innovations necessary for nuclear fusiondevices might be of commercial interest reected in patentingactivity. Plasma and laser physics, an important area for nuclearfusion, is not necessarily associated with nuclear fusion althoughimportant in nuclear fusion technology and might also per se becommercially interesting and thus be protected by patents. Particlephysics are also likely to be applied in other areas than nuclearfusion, e.g. breeding of tritium, or the handling of radioactivewaste,and thus be commercially interesting besides for nuclear fusiontechnology. Other elds of technology of special concern to fusionresearch are plasma coating and semiconductor production.

As can be seen in Fig. 1, documents retrieved by nuclear fusion-related keywords only are generally covered by nuclear fusionspecic patent classication codes up to about 1975. From then on,technologies which are related to fusion technologies but notassigned to nuclear fusion specic patent classication codes andare only retrieved by keywords play a more and more prominentrole in the overall count of patent documents relating to nuclearfusion. This observation may partly be an indication for fusiontechnology spillovers into other technological sectors and maydemonstrate that this spillover effect has increased in number andin importance during the last decades. On the other hand, tech-nologies identied by keywords only and not by nuclear fusionpatent classes may also indicate a diversication of inventions inthe nuclear fusion eld that are not necessarily classied undernuclear fusion. Such a diversication might have become necessaryfor example with the scaling up of experimental fusion reactors.

Patent landscaping maps were used to visualize the patent

Table 5Denition of technological sectors covered by patent documents which relate tonuclear fusion butwere not assigned the patent classication codes G21B, H05H1/02or 376/100 (including subsides). Four main technological sectors weredistinguished:

Technologicalsector

IPC codes

Materials science C04B35, C22C38, C22F1, C01B31, C30B29, C03C3, C22C27Particle physics H01J25, B01D59, G01T1, G21K1, H01J23, C01B4Plasma & laser

physicsH01S3, H05H1, B23K26, H01P1

Superconductivity H01B12, H01L39, H01B13, H01F6, H01F7, H01F5, H01F1

P. Bruns et al. / World Patent Information 34 (2012) 271e278 275elds outside fusion technology are materials science (assigned to14 per cent of the retrieved documents), superconductive or hyperconductive conductors (13 per cent), plasma and laser physics (7Fig. 3. Patent landscape map of patent documents relating to nuclear fusion, in the period 19main technical concepts of the underlying inventions. Patent documents relating to core tpoints) are distinguished. Important technical concepts are highlighted: beam sources andsuperconductivity in magnets (blue area).activity in different fusion technology areas and to identifyemerging new technology sectors (Fig. 3). Patent landscaping usesdata and text mining to analyze large numbers of patent documents

80e2009. The patent documents were subjected to data and text mining in order revealechnologies (red data points) and documents identied by keywords only (blue data

energy supply (red area), controlling magnetic elds and the plasma (orange area),

and to group patent documents relating to the same or similartechnologies. Figure 3 shows the patent landscape map of allretrieved patent documents (patent classication codes andkeywords) from 1980 to 2009. The red dots indicate patent docu-ments classied by nuclear fusion specic patent classicationcodes according to Table 1 whereas the blue dots represent thepatent documents not classied by these codes, are therefore not asclosely related to nuclear fusion as the documents represented bythe red dots and can be retrieved by keywords only.

Several distinct technological sectors can be identied byanalyzing patent landscaping maps. A large area with documentscovering plasma and magnetic elds and areas describing beamsources and energy supply can be distinguished. All these areas arepredominantly covered with red dots representing patent docu-ments closely related to nuclear fusion. Other areas, mostly coveredwith blue dots, seem to belong rather to spillover technologies thandirectly to nuclear fusion, e.g. superconducting and materialsciences. These identied documents or document clusters can beanalyzed in regard to spillover effects.

The citation of patent documents in subsequent patent appli-cations or in patent prosecution procedures is widely considered toprovide useful information about the dissemination of technolo-gies. Forward citation activities may also be an indicator of tech-nology and knowledge transfer from one technology eld coveredby the cited patent documents into other technology eldsaddressed by the citing patent applications.

The analysis of forward citations in this study is based on thegenerality concept [23]. This concept assumes that if one patentdocument is cited by other patent documents in a variety of othertechnical elds, it can be assumed that it has initiated or at least

system. The reason for using patent classication data on thesubclass level rather than on the more detailed subgroup level lieswithin the fact that analyzing the data on the subgroup level mayproduces statistical artefacts.

The forward citation analysis was performed by grouping theIPC codes of the citing patent documents according to the oldestpriority year of the cited document. For each oldest priority year,the percentage of citing patent documents having a specic IPCcode was then determined. This corresponds to a normalization ofthe data and allows to compare the IPC code distribution fordifferent oldest priority years. The resulting normalized distribu-tion was plotted and shown in Fig. 4. This gure illustrates thediversication of the nuclear fusion domain during the last decadesand the spillover into other technical elds.

As an example, the data point for the percentage of forwardcitations having the IPC subclass G06K (Recognition of data;presentation of data; record carriers; handling record carriers) andciting patent documents from 1949 is highlighted (see red circle inFig. 4). The data point represents 10e100 per cent (red color in theweb version) of all forward citations regarding patent documentsfrom 1949 (the actual value is 33 per cent). In other words, onethird of all forward citations which refer to patent documentsrelating to nuclear fusion and stemming from 1949 belongs to thetechnological sector characterized by the IPC subclass G06K.

The distribution illustrates that documents relating to nuclearfusion are not only cited by other nuclear fusion-related patentdocuments but by a signicantly broader set of documents. Whilethe majority of forward citations has the IPC codes relating tonuclear fusion, that is the core technologies or closely relatedtechnologies (Table 5), other non-nuclear fusion IPC subclasses play

P. Bruns et al. / World Patent Information 34 (2012) 271e278276inuenced innovations outside its own technical eld.The analysis of forward citations was performed in this study

using the subclasses of the International Patent ClassicationFig. 4. Forward citations of patent documents relating to nuclear fusion, per oldest prioritydocuments (see text for a more detailed description). The IPC domain G08B-H05K which calso a prominent role. For example, many citing patent documentshave the IPC code B23K which relates to inventions in the eld ofsoldering/welding. Soldering and welding aspects play anyear of the cited patent documents and per IPC code on the subclass level of the citingomprises various IPC codes relating to nuclear fusion is enlarged.

Infoimportant role in the development of reactor walls which arecapable of withstanding the harsh working conditions.

A second example for spillover effects identied by the forwardcitation analysis are documented in patent documents having theIPC code F04B covering pumps. Advanced pumping technology isa prerequisite for fusion reactors. Due to the necessity for a highvacuum and its upkeeping in fusion reactors, the nuclear fusioneld has come up with high-performance solutions for vacuumpumps. The technologies behind these solutions have meanwhilefound their way to other applications. For example, the modulargetter pump disclosed in US4137012A, which can be placed in theouter vacuum shell of a torus-type nuclear fusion reactor, wasreferred to in the subsequent patent document WO9837325A1,addressing getter pumps with a specic supporting framework tobe used in vacuum systems.

The presented analysis of forward citations aimed to illustratespillover effects of nuclear fusion and the diversication of thetechnical eld whereas a thorough quantitative statistical analysisof forward citations, e.g. based on the generality measure, wasbeyond the scope of this study. However, in light of the extensivedata basis for patent documents in the nuclear fusion eld, theauthors consider the quantitative analysis a promising and valuableapproach to further assess the economic side effects of research innuclear fusion.

4. Conclusions

Results of the patent analyses suggest that spillover and spinoffeffects are real for nuclear fusion research. The data demonstratesthat patents belonging to non-nuclear fusion technologies but arelinked to nuclear fusion can be found in patent analysis approachessuch as forward citation analysis. In fact, the diversity of possibleapplication of technologies stemming from nuclear fusion researchis somewhat surprising.

Our study does not take into account the economic impact ofspillovers and spinoffs in the eld of nuclear fusion. These effectshave to be analyzed separately and in detail using the patents andtechnologies identied by our approach. Nevertheless, ourapproach can enable economists and decision makers to assessspillover effects of complex technology areas and systematicallyrather than anecdotally investigate their impact on economicadvance and social developments.

Acknowledgments

We would like to acknowledge Hansueli Stamm for criticallyreading the manuscript and Markus Sigrist for helpful discussionsand inputs. We also acknowledge the help of Stefanie Schneiterwith the preparation of the gures and the Swiss Federal Instituteof Intellectual Property for supporting this work.

References

[1] Directorate-General for Research, European Commission. Fusion research: anenergy option for Europes future. Luxembourg: European Communities;2007.

[2] Preuss P, Kwan J. On the road to fusion energy, an accelerator to study warmdense matter. Berkley: Lawrence Berkeley National Laboratory; 2009.

[3] Del Rosso A. Energy options and the role of nuclear fusion. CERN CourierAugust 2008.

[4] Holdren JP. Fusion energy in context: its tness for the long term. Science1978;200(4338):168e80.

[5] Voss D. Fast track for fusion. Science 2006;314(5804):1357.[6] Kikuchi M. Frontiers in fusion research. London: Springer-Verlag; 2011.[7] Jaffe AB. The importance of spillovers in the policy mission of the advanced

technology program. Journal of Technology Transfer 1998;23(2):11e9.

P. Bruns et al. / World Patent[8] Nail J, Brown H. Identifying technology ows and spillovers through NAISCcoding of ATP project participants In: NISTIR 7280, Gaithersburg; 2006.18th Symposium on fusion engineering, Albuquerque; 1999.[18] Dean St. Applications of plasma and fusion research. Journal of Fusion Energy

1995;14(2):252e79.[19] Cozzens S. Methods for evaluating fundamental science. Washington, DC: The

Rand Corporation; 1994.[20] Nelson AJ. Measuring knowledge spillovers: what patents, licenses and

publications reveal about innovation diffusion. Research Policy 2009;38:994e1005.

[21] Weynat T, Olavson T. Issues in modelling induced technological change inenergy, environmental and climate policy. Environmental Modelling andAssessment 1999;4(2e3):67e85.

[22] David PA, Mowery D, Steinmueller WE. Analysing the economic payoffsfrom basic research. Economics of Innovation and New Technology 1992;2:73e90.

[23] Organisation for Economic Co-operation and Development. OECD patentstatistics manual; 2009. p. 111e6.

Peter Bruns is currently head of patent experts in engi-neering at the Swiss Federal Institute of IntellectualProperty which he joined in 2002. Prior to the work in IP,he was for ten years at universities and research institu-tions in Germany, the U.S. and The Netherlands performingbasic research in geochemical studies of marine sedimentsand investigated past environmental changes. He holdsa master and a doctorate degree in geology from theUniversities of Heidelberg and Kiel.

Minh Quang Tran Educated at the EPF Lausanne (EPFL)and having received his PhD in plasma physics, he spenthis post doc years at the Plasma Physics Laboratory of theUCLA. He then returned to Centre de Recherches enPhysique des Plasmas (CRPP) of the EPFL to work asa principal investigator in many different elds, such asbasic plasma physics, development of high power milli-meter waves sources, electron cyclotron heating of fusiondevices. He became Full Professor of Plasma Physics at theEPFL in 1997 and Director of the CRPP in 1999. He was also

in charge of the implementation of the European EFDA activities as EFDA Leader from2003 to 2006. In parallel with his activities at the CRPP, he also serves as chair ormember of many international panels.

Daniel Kunz is a patent expert in the eld of mechanicalengineering at the Swiss Federal Institute of IntellectualProperty. Before he started working at the Institute in2005, he held positions for ten years in pressure, force andtorque metrology. Amongst others he was head of thepressure laboratory at the Federal Ofce of Metrology(METAS) for several years. Since 2006, he has beenresponsible for patent statistical analysis at the Institute.He has a university of applied science degree in mechan-international Europhysics conference e high energy physics 99, Tampere;1999.

[14] European Commission, Directorate-General for Research. Fusion energy emoving forward. spin-off benets from fusion R&D: information andcommunication unit. Brussels: European Commission; 2003.

[15] Gnansounou E, Bednyagin D. Estimating spillover benets and social rate ofreturn of fusion research, development, demonstration and deploymentprogram: conceptual model and implications for practical study. EFDA socio-economic research on fusion task: TW5-TRE-FESS/D. Lausanne: Ecole Poly-technique Federale de Lausanne; 2007.

[16] Rasmussen D, Schoenberg K, Siemon R, Zweben SJ. Near term applications ofplasma science and fusion research: national laboratory perspectives. Journalof Fusion Energy 1998;17(2):103e15.

[17] Kulcinski GL. Non-electric power, near-term applications of fusion energy. In:[9] Maurseth PB, Verspagen B. Knowledge spillovers in Europe: a patent citationanalysis. Scandinavian Journal of Economics 2002;104(4):531e45.

[10] Cohendet P. Evaluating the industrial indirect effects of technology pro-grammes: the case of the European Space Agency (ESA) programmes. In:Proceedings of the OECD conference. Paris: Policy Evaluation in Innovationand Technology; 1997.

[11] Livingston D. Is space exploration worth the cost? The Space Review 2008,January 21.

[12] Jaffe AB. Economic analysis of research spillovers e implications for theadvanced technology program. Gaithersburg: National Institute of Standardsand Technology; 1996.

[13] Amaldi U. Spin-offs of high energy physics to society. In: Proceedings of

rmation 34 (2012) 271e278 277ical engineering.

Heinz Mueller Educated at the ETH Zurich and havingreceived his PhD in biochemistry, he worked for severalyears at different research institutions in San Diego andChicago. He then returned to Switzerland to work asa principal investigator in cancer research at the Universityof Basel where he obtained the title of a professor. Severalyears ago he joined the patent department of the SwissFederal Institute of Intellectual Property while remaininga regular lecturer in biochemistry at the University ofBasel. He also teaches intellectual property at differentSwiss universities and writes articles for several publica-tions on this topic.

Christian Soltmann has worked for several years asa materials scientist in the eld of pure and appliedresearch. In addition to a PhD in materials science, heholds a MAS in Intellectual Property. He is a patentexpert at the Swiss Federal Institute of IntellectualProperty and specializes in patent statistics and datamining.

P. Bruns et al. / World Patent Information 34 (2012) 271e278278

Spillover benefits from controlled nuclear fusion technology A patent analysis1. Introduction2. Methods2.1. The data set2.2. Statistical analysis

3. Results and discussion4. ConclusionsAcknowledgmentsReferences