Inventing our future accelerator

Can you imagine that electrons

Are planets circling their suns?

Space exploration, wars, elections

And hundreds of computer tongues

Translation by A Seryi of a 1920 poem by Valery Bryusov, “The World of Electron”

Accelerator science and technology exhibits a rich history of inventions that now spans almost a century. The fascinating story of accelerator development, which is particularly well described in Engines of Discovery: A Century of Particle Accelerators by Andy Sessler and Ted Wilson (CERN Courier September 2007 p63), can also be summarized in the so-called “Livingston plot”, where the equivalent energy of an accelerated beam is shown as a function of time. The plot depicts how new accelerating technologies take over once the previous technology has reached its full potential, so that over the course of many decades the maximum achieved energy has continued to grow exponentially, thanks to many inventions and the development of many different accelerator technologies. The most recent decades have also been rich with inventions, such as the photon-collider concept (still an idea), crab-waist collisions (already verified experimentally at the DAFNE storage ring in Frascati) and integrable optics for storage rings (verification is planned at the Integrable Optics Test Accelerator at Fermilab), to name a few.

Despite recent inventions, however, there is some cause for anxiety about the latest progress in the field and projections for the future. The three most recent decades represented by the Tevatron and the LHC exhibit a much slower energy growth over time. This may be an indication that the existing technologies for acceleration have come to their maximum potential, and that further progress will demand the creation of a new accelerating method – one that is more compact and economical. There are indeed several emerging acceleration techniques, such as laser-driven and beam-driven plasma acceleration (CERN Courier June 2007 p28), which can perhaps bring the Livingston plot back to the fast-rising exponent. Nevertheless, inspired by the variety of past inventions in the field, and dreaming about future accelerators that will require many scientific and technological breakthroughs, we can pose the question: how can we invent more efficiently?

It is worth recalling two biographical facts about two prominent accelerator scientists: John Adams, who in the 1950s played the key role in implementing the courageous decision to cancel the already approved 10 GeV weak-focusing accelerator for a totally innovative 25 GeV strong-focusing machine (the CERN Proton Synchrotron), and Gersh Budker, who was the founder and first director of the Institute of Nuclear Physics, Novosibirsk, and inventor of many innovations in the field of accelerator physics, such as electron cooling. It is important in this context that Adams had a unique combination of scientific and engineering abilities, and that Budker was once called by Lev Landau a “relativistic engineer”. This connection is indeed notable, because the art of inventiveness that I am about to discuss came from engineering.

While everyone has probably heard about problem-solving approaches such as brainstorming or even its improved version, synectics (the use of a fairy-tale-style description of the problem is one of its approaches – note the snakes in figure 1c representing the magnetic fields in the solenoid), it is likely that most people working in science have never heard about the inventive methodologies that engineers have developed and used. It is indeed astonishing that formal inventive approaches, so widely used in industry, are rarely known in science.

One such approach is TRIZ – pronounced “treez” – which can be translated as the Theory of Inventive Problem Solving. TRIZ was developed by Genrikh Altshuller in the Soviet Union in the mid-20th century. Starting in 1946 when he was working in a patent office, but interrupted by a dramatic decade-long turmoil in his life (another story) that he overcame to resume his studies, Altshuller analysed many thousands of patents, trying to discover patterns to identify what makes a patent successful. Following his work in the patent office, between 1956 and 1985 he formulated TRIZ and, together with his team, developed it further. Since then, TRIZ has gradually become one of the most powerful tools in the industrial world. For example, in his 7 March 2013 contribution to the business magazine Forbes, “What Makes Samsung Such An Innovative Company?”, Haydn Shaughnessy wrote that TRIZ “became the bedrock of innovation at Samsung”, and that “TRIZ is now an obligatory skill set if you want to advance within Samsung”.

A methodology

The authors of TRIZ devised the following four cornerstones for the method: the same problems and solutions appear again and again but in different industries; there is a recognizable technological evolution path for all industries; innovative patents (which are about a quarter of the total) use science and engineering theories outside of their own area or industry; and an innovative patent uncovers and solves contradictions. In addition, the team created a detailed methodology, which employs tables of typical contradicting parameters and a wonderfully universal table of 40 inventive principles. The TRIZ method consists in finding a pair of contradicting parameters in a problem, which, using the TRIZ inventive tables, immediately leads to the selection of only a few suitable inventive principles that narrow down the choice and result in a faster solution to a problem.

TRIZ textbooks often cite Charles Wilson’s cloud chamber (invented in 1911) and Donald Glaser’s bubble chamber (invented in 1952) as examples – to use the terminology of TRIZ – of a system and anti-system. Indeed, the cloud chamber works on the principle of bubbles of liquid created in gas, whereas the bubble chamber uses bubbles of gas created in liquid (figure 1a). If the TRIZ inventive principle of system/anti-system were applied, the invention of the bubble chamber would follow immediately and not almost half a century after the invention of the cloud chamber.

Another TRIZ inventive principle, that of Russian dolls (nested dolls, or matryoshki), can be applied not only to engineering but also in many other areas, including science or even philology. The principle of a concept inside a concept can be seen in the British nursery rhyme “This is the house that Jack built”, and the 1920 poem by Valery Bryusov (quoted at the start), which describes an electron as a planet in its own world, can also be seen as a reflection of the nested-doll inventive principle, this time in poetic science fiction. A spectacular scientific example is the construction of a high-energy physics detector, where many different sub-detectors are inserted into one another, to enhance the accuracy of detecting elusive particles (figure 1b). Such detectors are needed to find out if there is indeed a world inside of an electron – and the circle is now closed!

The TRIZ method can be applied, in particular, to accelerator science. For example, the dual force-neutral solenoid found in the interaction region of a collider, or in NMR scanners, is an illustration of both the nested-doll and the system/anti-system inventive principles. Two solenoids of opposite currents are inserted in one another in such a way that all of the magnetic flux-return is between the solenoids and none is seen outside, reducing the need for magnetic shielding in case of NMR or reducing interference with the main solenoid of the detector in case of a particle collider (figure 1c). Remarkably, the same combination of inventive principles can be seen in the technique of stimulated emission depletion microscopy (STED), which was rewarded with the 2014 Nobel Prize in Chemistry. The final focus system at a collider with non-local chromaticity correction is an illustration of the inventive principle of what is known as “beforehand cushioning”. And so on.

While many of the TRIZ inventive principles can be applied directly to problems in accelerator science, it is tempting to add accelerator-science-related parameters and inventive principles to TRIZ. The equations of Maxwell or of thermodynamics, where an integral on a surface is connected to the integral over volume, suggest an inventive principle of changing the volume-to-surface ratio of an object. Nature provides an illustration in a smart cat, stretched out under the sun or curled up in the cold, but flat colliding electron–positron beams or fibre lasers also illustrate the same principle. Another possible inventive principle for accelerator science is the use of non-damageable or already damaged materials: the laser wire for beam diagnostics, the mercury jet as a beam target, plasma acceleration, or a plasma mirror – the list of examples illustrating this inventive principle can be continued.

So the TRIZ method of inventiveness, although created originally for engineering, is universal and can also be applied to science. TRIZ methodology provides another way to look at the world; combined with science it creates a powerful and eye-opening amalgam of science and inventiveness. It is particularly helpful for building bridges of understanding between completely different scientific disciplines, and so is also naturally useful to educational and research organizations that endeavour to break barriers between disciplines.

However, experience shows that knowledge of TRIZ is nearly non-existent in the scientific departments of western universities. Moreover, it is not unusual to hear about unsuccessful attempts to introduce TRIZ into the graduate courses of universities’ science departments. Indeed, in many or most of these cases, the apparent reason for the failure is that the canonical version of TRIZ was introduced to science PhD students in the same way that TRIZ is taught to engineers in industrial companies. This may be a mistake, because science students are rightfully more critically minded and justifiably sceptical about overly prescriptive step-by-step methods. Indeed, a critically thinking scientist would immediately question the canonical number of 40 inventive principles, and note that identifying just a pair of contradicting parameters is a first-order approximation, and so on.

A more suitable approach to introduce TRIZ to graduate students, which takes into account the lessons learnt by its predecessors, could be different. Instead of teaching graduate students the ready-to-use methodology, it might be better to take them through the process of recreating parts of TRIZ by analysing various inventions and discoveries from scientific disciplines, showing that the TRIZ inventive principles can be efficiently applied to science. In the process, additional inventive principles that are more suitable for scientific disciplines could be found and added to standard TRIZ. In my recent textbook, I call this extension “Accelerating Science (AS) TRIZ”, where “accelerating” refers not to accelerators, but instead highlights that TRIZ can help to boost various areas of science.

Many of the examples of TRIZ-like inventions in science considered above have already been made, and I am being deliberately provocative in connecting them to TRIZ post factum. However, it is natural to wonder whether TRIZ and AS-TRIZ could actually help to inspire and create new scientific inventions and innovations, especially in regard to projects that continue to manifest many unsolved obstacles.

One example of such a project is the circular collider currently being considered as a successor to the LHC – the Future Circular Collider (FCC), a 100 km circumference machine (CERN Courier April 2014 p16). This project has many scientific and technical tasks and challenges that need to be solved. Notably, the total energy in each circulating proton beam is expected to exceed 8 GJ, which is equivalent to the kinetic energy of an Airbus-380 flying at 720 km/h. Not only does such a beam need to be handled safely in the bending magnets, it also needs to be focused in the interaction region to a micrometre-size spot – the equivalent, more or less, of having to pass through the eye of a needle.

It remains to be seen if the methodology of TRIZ and AS-TRIZ can be applied to such a large-scale project as the FCC, because it brings a whole array of new, difficult and exciting challenges to the table. Nonetheless, it is certainly a project that can only flourish with the application of knowledge and inventiveness.