In November 1945 the US forces occupying Japan started dumping large metal objects into the waters of Tokyo Bay. Gathered on the deck of their ship, the sailors watched as these strange, alien creations were slowly edged off the side. One by one, the objects’ lines were loosened and they began to topple overboard, hitting the water with a satisfying sploosh as they descended to their watery grave.
Back on dry land, Yoshio Nishina was distraught. The hunks of metal thrown into the sea were the remains of his cyclotrons. A month earlier, he had been granted permission to continue using them for medical, chemical and metallurgical research. But Robert Patterson, the US secretary of war, had changed his mind. Over a period of five days, working day and night, Nishina’s machines had been ripped apart by engineers from the Eighth United States Army. A short time later, the engineers would also destroy cyclotrons in Osaka and Kyoto, even smashing a beta-spectrometer for good measure after misinterpreting a joke from one of the aghast scientists. It was pure vandalism: the destruction of every particle accelerator in Japan.
Nishina was one of the leading nuclear physicists in the world. In 1918 he had graduated from Tokyo Imperial University as an electrical engineer and had joined the Japanese Institute of Physical and Chemical Research (RIKEN). In 1921 he had been sent as a student to tour the research institutes of Europe, where he had become good friends with Niels Bohr. On his return to Japan, he had established his own laboratory and set out to probe the mysteries of the atom.
RIKEN was a unique set-up: a network that could be described as both independent research laboratories and a zaibatsu or business conglomerate. Founded in 1917 by scientists worried that Japan was losing step with the major powers, RIKEN’s mission was, according to its architect Eiichi Shibusawa, to ‘turn the country from imitation to creative power […] to promote research in pure physics and chemistry’. Initially, the Japanese government had refused to back it, so instead it had been set up thanks to private donations, including some from the imperial family. For Nishina, RIKEN provided the perfect base for his research into quantum mechanics – and a backer with enough resources to help him discover a new element.
Japanese science had been trying to make its name in the world of element discovery since the start of the twentieth century. It had come close several times. In 1908 Masataka Ogawa, working under William Ramsay at University College London, had been testing a sample of thorianite when his chemical analysis came across something unknown. Ramsay, who had discovered the noble gases a few years earlier, encouraged the young chemist to publish his findings. Ogawa claimed he had discovered element 43, and called it ‘nipponium’ after his homeland. On his return to Japan, Ogawa had tried to follow up on his experiments – good science requires repetition, after all – but had been thwarted by a lack of modern equipment. Eventually, the claim was dismissed. Some modern researchers suspect Ogawa had discovered element 75 (today called rhenium) and misidentified it. If so, it was an easy mistake to make: both elements were in the same group in the periodic table and have similar chemical characteristics.
Nishina had also come close to discovering an element. Following Ernest Lawrence’s blueprint, in 1937 he had built his own cyclotron, the first such machine made outside the US, which he had used to bombard thorium with fast neutrons, discovering the isotope uranium-237. This was a beta emitter and decayed into the then-undiscovered element 93. Nishina almost certainly created neptunium before Edwin McMillan and Phil Abelson confirmed their discovery – yet, like Ogawa before him, he hadn’t been able to prove his new element.1
In April 1941, while Nishina was still trying to prove his discovery, he found his resources diverted. By then it had become clear that, for Japan to further its ambitions in the Pacific, war with the US was inevitable. RIKEN became occupied by project Ni-Go – one of the Japanese attempts to make a nuclear weapon. Nishina (the ‘Ni’ in the code name) was put in charge of the project and assigned himself the hardest task: enriching uranium.
Nishina had doubts that his homeland, with its lack of natural resources, could ever build an atomic bomb.2 However, Ni-Go meant even more funding for his cyclotrons, so he played along. By 1944 RIKEN had created a 220t cyclotron that was a twin of its counterpart at Berkeley. Ostensibly it was to help make the weapon; in reality it was a research tool. Wisely, Nishina decided to keep the truth to himself.
Project Ni-Go collapsed soon after. In April 1945 RIKEN’s main laboratories were bombed, destroying its thermal diffusion equipment. A month later, a German U-boat loaded with of 560kg (1,235lb) of uranium destined for Japan – a last, desperate throw of the dice by the Axis powers – was captured in the Atlantic. In June, Nishina told his superiors that the bomb project was over: a nuclear weapon was simply unfeasible.
The morning of 6 August 1945 changed his mind. A single bomb fell on the city of Hiroshima, levelling 12.2km2 (4.7 miles2) of the city and destroying almost 70 per cent of its buildings. Around 80,000 people died in the initial blast and immediate firestorm. A further 70,000 were injured, many with their clothes seared into their skin. Nishina was summoned to a secret government meeting where, despite the strict wartime censorship, he was shown a release from US President Truman. There, in front of worried officials, Nishina had confirmed Truman’s claim that the one bomb ‘had more power than 20,000 tons of TNT’.
It marked the end of the Empire of Japan. Heading to Hiroshima to survey the damage first-hand, Nishina left a note for one of his staff. ‘If Truman is telling the truth, it is now the time for those involved in the Ni-Project to commit hara-kiri [ritual suicide].’ Evidently, he reconsidered.
After the war, Nishina tried to preserve his cyclotrons, hoping they could help his country rebuild. As his creations fell into the sea, he knew he had nothing to offer. ‘By the sad and untimely destruction,’ he later wrote in Bulletin of the Atomic Scientists, ‘[the cyclotrons were] robbed of any chance to make contributions to science.’ In Oak Ridge, the US scientists agreed, slamming the desecration of the machines as ‘wanton and stupid to the point of constituting a crime against mankind’. Japanese science was dead in the water.
It was the least of the country’s woes. For the first time in its history, Japan was an occupied country, its people starving, its culture and heritage reshaped and reforged by a victorious US. Rather than give up on his life’s work, Nishina wrote to the Americans, asking for help to teach nuclear physics again. The response was blunt: ‘All of Japan is hungry. If I were Japanese, I would take a shovel [and plant crops].’
Nishina ignored the advice and resumed his research. By the time of his death in 1951, Japan was on the road to recovering its lost scientific prestige. Yet it was still missing an element to call its own. RIKEN was on a mission to honour the legacies of Ogawa and Nishina. The emperor of Japan had helped establish the institute – and RIKEN wanted to repay the debt with a new element.
* * *
Tokyo is basking in a heatwave. The temperature is past 40 °C, but the hive never abates, never ceases and never stops. Commuters, packed like sardines, desperately fan themselves to stay cool; kids in school uniforms swoon even as they remain glued to their phone screens; waitresses dressed as French maids, dolphins or game characters try to lure passing customers into their cafes. Above and around, everywhere, blares electric activity. Anime creations wave at you from LED billboards, calling for your attention as a kaleidoscopic shower of stars cascades behind them. Trains course through the city’s underground arteries in perfect synchronicity, rarely late or cancelled, while birdsong is piped onto the platforms to grant a moment’s calm among the crowds. This is modern Japan – a blur of motion even the sweatbox heat can’t slow.
At the far end of the Tokyo metro, the last stop on the sprawling tentacle of lines that make up the metropolis’ subway, is Wakōshi Station. Here, the action gives way to a more sedate, suburban pace. Venture out of the station’s south gate and look down. You’ll see a bronze plaque emblazoned with an H: hydrogen. Further down the street is helium; then lithium; then beryllium. Keep following. The clattering pachinko arcades give way to sleepy suburban homes and neat company outposts. Eventually, you’ll find yourself heading toward RIKEN’s Wakō campus, home to its Nishina Center for Accelerator-Based Science.
Today, RIKEN is the largest research body in Japan, famed for pioneering work in areas such as pharmaceuticals, agriculture and neuroscience. Almost entirely government funded, its products appear in every corner shop of Japan, from energy drinks that make the body burn fat rather than carbohydrates to cosmetics based on amber. In 2010 the Nishina Center team used their accelerator to shoot carbon ions at cuttings from cherry blossom trees. The mutated blossoms – Nishina otome – bloom twice a year. In a country where cherry blossom viewing is a televised event, this is a big deal.
I’m not here to talk about any of those discoveries. I want to know why RIKEN joined the race to search for superheavy elements in the 1990s – and how it beat everyone else to the discovery of element 113. It’s the element emblazoned on the last plaque on the walk from the station, a final marker that brings you to an abrupt stop outside RIKEN’s gates.
‘It looks like you’ve run out of space for plaques,’ I say to my guide, Yukari Onishi, as she escorts me into the air-conditioned sanctuary of the main building. ‘What happens if you discover another?’
‘I don’t know!’ she laughs. ‘I guess we’ll have to lead them right up to the building. And after that start putting them indoors.’
Reminders of the hunt for elements are everywhere: in the foyer of the Nishina Center is a chart of the known nuclides created in Lego, the 3D model stretching up to show the instability of each isotope; with it, you can see the dip around the island of stability, teasing the element makers with its proximity.
In the US or Europe, discovering a new element barely registers on the evening news. In Japan, element discovery is followed as a national obsession. Hideto En’yo, the Nishina Center’s director, remembers when the team detected one of the atoms that proved their claim. ‘My daughter was in high school,’ he recalls. ‘I was about to visit and I told her I couldn’t because something had happened. And she just said “Oh, you must have created an atom of element 113!” The high school students all know about our research.’
En’yo is youthful in appearance, his jet-black hair neatly combed, a broad smile on his face. He laughs long and often, more than happy to talk about the crowning achievement of his career. First, though, I need to present my gift. Business is ritualised in Japan, an elaborate and complex riddle of etiquette and social status where even bowing to the wrong degree can cause offence. When you present your business card (and you do, to everyone in the room in turn), you do so holding it on its corners, waiting for them to take it. When you receive a card, you read the name and keep it in a place of pride, never in your trousers. If someone is more important than you are, you always place your business card under their own. And when you visit a company for the first time, you try to bring a gift. As a visitor I’m not expected to do this, but it seems only polite to follow the local customs. En’yo takes my offering – a Royal Society of Chemistry cricket cap – with a smile. It seems the effort is appreciated.
‘Discovering an element was a dream from Japan’s history,’ En’yo begins. ‘A dream to recover from a mistake.’ He’s talking about Ogawa’s ‘nipponium’ – failures sit heavy in Japan. ‘And also Nishina, he tried to make a new element. He did it. OK, he couldn’t confirm it, but if you judge him by present knowledge, clearly, he did it. He just didn’t get the naming rights! For Japan, [discovering an element] has been a century-long project.’
The person the nation put its hopes on was Kōsuke Morita. There is even a manga comic about him, his cartoon alter ego imagined as a tubby figure with a bald pate and thick glasses. A nuclear physicist from Fukuoka, Morita left Kyushu University without completing his thesis (later insisting that he did not have the talent to finish it) and joined RIKEN as a researcher. In 1992 he went to Dubna, where he learned how to make elements under Yuri Oganessian. When it came time for Japan to enter the element discovery race, he was the natural choice to run the show. ‘More than 30 years ago, Kōsuke Morita was charged to look into [element discovery],’ En’yo explains. ‘He needed 10 years to catch up with the world. Twenty years ago, we built the biggest atom smasher in the world. Then we were ready to compete. In 2003 we started the experiment – and we were going to win the game.’
En’yo isn’t exaggerating. RIKEN’s linear accelerator, RILAC, was easily capable of competing with GSI’s own monster machine. It also has arguably the best detector in the world. But the team hadn’t been able to procure calcium-48, and the machine wasn’t set up to handle radioactive targets. While the Russians and Americans were racing ahead with hot fusion, the Japanese would have to use cold fusion instead.
It wasn’t a bad call but this made discovery far harder. As the predicted reaction cross sections were much lower, fusion events would be much rarer than for the Dubna–Livermore group. But Morita’s team had near-unlimited beam time. Element-making is like spinning a giant roulette wheel with a million numbers – spin it enough times and eventually your number will come up. If they ran their cold fusion experiment for long enough they were bound to get something. All they had to do was hope their results came before their rivals’.
It was a long shot.
In 2003 the Japanese team started bombarding bismuth targets with zinc-70 ions. In 2004 the team got their first hit: an isotope that decayed in 0.34 milliseconds. Even so, it seemed the race had been lost: six months earlier, the Dubna–Livermore group had already reported the discovery of element 113 from the alpha decay of element 115.
Yet neither team’s claim was accepted immediately. The problem (for both teams) was that the alpha decay chains they reported broke down into undiscovered isotopes – meaning it was impossible to double-check if the results tallied with previous knowledge. There were also some inconsistencies with known data, probably due to the broad range of energies that elements with odd-numbered protons can produce. The IUPAC team arbitrating on element discovery ruled that both teams had produced ‘very promising’ evidence that was ‘approximately contemporaneous’. However, it wasn’t enough to say that the element had been made.
‘The discovery was about who made element 113 without reasonable doubt,’ En’yo explains. ‘It’s like an umpire: if they say “you win”, the other side says “you’re wrong”. We were all left wondering … Dubna tried to directly create element 113, and they had two events. A month later, we had one event. They were faster than us, but they gave up.’
En’yo is half right. While the Dubna–Livermore group moved on, it was to focus on chemical experiments to shore up their discoveries – less taking a break, more gathering intelligence. ‘In our minds, we had discovered two elements with one experiment – how economical! – and we were continuing to perform key experiments,’ says Mark Stoyer. ‘That is not giving up.’
Both teams continued to push, and by 2005 both had two direct ‘hits’. It still wasn’t enough to prove they had made the element. Going back to En’yo’s umpire analogy, they needed another strike to end the game.
It didn’t come for seven years.
* * *
In 1927 Thomas Parnell, at the University of Queensland in Brisbane, Australia, wanted to show his students that sometimes things that appear solid are, in fact, just really viscous liquids. Gathering his class, he heated a sample of pitch – the same stuff used to coat the bottom of ships – and plopped it in a sealed funnel. Three years later, he cut the neck of the funnel, placed the experiment outside the lecture hall and allowed the pitch to start flowing out of the bottom. The first drop fell five years later, in 1938.
Currently, the ‘pitch drop’ holds the world record for the longest continuously running lab experiment. It produces a single drop about once a decade – so far it’s up to nine drops. The experiment (like Livermore’s light bulb) is monitored constantly by webcam. John Mainstone, who inherited the experiment from Parnell, never saw the drop despite watching the pitch almost religiously for over 50 years. In 1988 he missed the rare event by minutes. ‘I decided that I need a cup of tea or something like that, walked away, came back, and lo and behold it had dropped,’ he told National Public Radio with a heavy heart. ‘One becomes a bit philosophical about this.’
The pitch drop has nothing on RIKEN. Heating up pitch and leaving it alone isn’t particularly expensive, and you can see when a drop is ready to fall for about a year in advance. RIKEN’s hope involved blasting 6 trillion ions a second for months at a time at their rotating bismuth targets, hoping to see an unpredictable event that wouldn’t even last a thousandth of a second.
RIKEN’s control centre is organised chaos compared with the elegance of GSI or the industrial brutalism of Dubna; it feels like a cyberpunk lair. We’ve headed upstairs from the meeting room, into the workhorse section of the lab, away from the Lego models and into a realm of 24/7 science. Wires swarm out of circuit boards, monitors pile up and stained bins are filled with discarded energy drinks. The chairs are beaten and cosy. The whole place has a hum of sweat, perseverance and toil. Along the top of the control deck are two brightly coloured plush toys, a couple of creatures that look something like monkeys in space suits.
‘They are Wakō City’s mascots,’ one of my hosts remarks. I forgot everything in Japan has its own mascot. Cities. Fire departments. Schools. Does RIKEN have a mascot?
Awkward silence. ‘Uh … yes and no. There was one, once. It was a sort of, uh, termite.’ A team member gives the Wakō mascots a reassuring pat. I get the distinct impression the space monkeys aren’t going to be replaced any time soon.
I’m guided to a computer screen, a host of applications open on its desktop. To the side is a white block showing some kind of radioactive trace. In the centre of the screen is an immediate contrast: a black box with a red cross at its heart. It looks like an old computer game from the 1980s: no fancy graphics, just x marks the spot. ‘This is element 113,’ I’m told by my guide – they’ve called up the record of what they saw in 2012 to demonstrate what an event looks like. ‘This white screen, here, means there’s been an implantation event.’ That’s when a newly fused element ricochets off and implants on the detector. ‘A red cross means you have an alpha-like event.’ The ricochet has decayed. ‘Three of those, you get a new element.’
It’s hard to imagine how seeing that little cross – a single atom of element 113 – must have felt. It reminds me of the old video game Desert Bus, in which the player drives on a straight road for eight hours. Complete one trip and you get one point. It’s so mind-numbing that gamers play it as an endurance feat to raise money for charity.3 Most beam line scientists describe a single night running their machines as a tough ask: a crucible under which tempers fray and everybody slowly goes a little insane. At RIKEN, a team of 50 scientists spent a cumulative total of 553 days of beam time just to see a little cross appear on a screen 3 times.
They almost didn’t succeed. By 2011 Morita’s team had spent most of their budget, and the experiment was on the verge of being shut down. Bismuth and zinc are pretty cheap materials, but even so the team had burned through $3 million in electricity. There was also increased pressure to use RILAC for other, equally important experiments with a higher probability of success. Morita refused to back down. ‘I was not prepared to give up,’ he later said, ‘as I believed that one day, if we persevered, luck would fall upon us again’. Morita would head to nearby shrines and temples in his spare time and pray, placing exactly 113 yen as an offering to the gods.
Then came an unlikely intervention. On 11 March 2011 the Tōhoku earthquake, the fourth largest quake ever recorded, shook Japan. It was the costliest disaster in history: almost 16,000 people were killed, almost 250,000 lost their homes and the destruction was valued at some $235 billion. In Fukushima, a nuclear power plant suffered three meltdowns, creating the largest nuclear incident since Chernobyl. In its aftermath, electricity prices across Japan skyrocketed. RIKEN’s Nishina Center – which has eye-watering electricity bills at the best of times – went into effective shutdown. The element hunters saw an opportunity.
‘It’s a bit strange,’ En’yo admits. ‘The earthquake starved us of electricity, so there was great pressure not to do a lot. So, we said “OK, we just want to do one experiment.” It meant we could run [the element search] most of the time. For two years, we shrank all of our operations except for the 113 search.’
In August 2012 the third event appeared. ‘We had six alpha decays, seven after a beta decay,’ En’yo recalls, thinking back to the red cross appearing on the monitor. ‘And now there was no doubt about it – we had discovered element 113. We dedicated that third event to the people of Fukushima.’
The result, coming off the back of nine years of solid work, turned the Japanese team into overnight legends among the superheavy community. ‘Imagine coming to work each 24-hour day for almost two years, and seeing no events on all but three days,’ wrote Walter Loveland and David Morrissey in Modern Nuclear Chemistry. ‘It requires an unusual degree of fortitude and courage.’ Dawn Shaughnessy’s praise is just as effusive: ‘The Japanese team were pretty hardcore. I have nothing but mad respect for what they did.’
In 2015 the IUPAC working party met again. Both the Russian–American and Japanese teams had strengthened their cases. Researchers in Lund, Sweden, had confirmed the Dubna results, while the RIKEN group had directly synthesised new isotopes of bohrium, proving that it linked up with their recorded element 113 alpha decay chain.
It was a dead heat, and the element could have been awarded to either team. But ultimately, the working party found that the Dubna–Livermore claim hadn’t fulfilled all criteria for discovering an element. The Russians were incensed: there was little doubt they had discovered the element first, and they had spent eight years and thousands of hours of beam time too. But the IUPAC decision was final – element 113 had been discovered by RIKEN.4
For 100 years, Japan had dreamed of an element on the periodic table. Finally, it had one. The celebration was so large it was even attended by Crown Prince Naruhito, honouring the imperial family’s long-standing connections to RIKEN. ‘I am deeply moved by the addition of the new element,’ he stated – before observing that he used to copy out the periodic table by hand in high school. In Japan, there could be no higher praise.
Dubna and Livermore had toasted their successful discovery of 114 and 116 with ‘flerovium’ vodka and ‘livermorium’ wine. RIKEN went a little further. In 2010 the Nishina Center team had put a batch of brewing yeast into their RILAC beam and induced mutagenesis – changing its genetic code to create an entirely new strain. The result was Nishina Homare sake (‘in honour of Nishina’). What better way to celebrate an element than mutant rice wine created from your own ion cannon?
Perhaps the most cathartic moment was the choice of name. ‘Nipponium’ was out of the question – Ogawa had already used it for his misidentified ‘element 43’, and IUPAC’s rules were clear that a name couldn’t be repeated. But there are two words in Japanese for their homeland, the land of the Rising Sun: Nippon and Nihon. Element 113 became ‘nihonium’.
* * *
‘Why produce new elements and isotopes? It’s a good question. They have short half-lives and no practical application.’ Hiromitsu Haba, one of the RIKEN chemists, takes his time as he thinks about the answer. Haba is one of the team who dedicated over a decade of their lives to hunting down element 113. What makes that level of commitment worth it?
‘The elements are very important for the universe, for the body, for everything!’ Haba says finally. ‘If we can understand such elemental particles, we can come up with good theories. Currently, we know 3,000 isotopes. But, theoretically, there are 10,000 isotopes. We only know a third of our world.’
Haba is referring to the latest models. Since Maria Goeppert Mayer and Hans Jensen blew the understanding of the nucleus wide open with their shell model, physicists have been trying to work out just how far the periodic table stretches – how much of the building blocks of existence remain undiscovered. Usually, this is presented as the chart of nuclides – like RIKEN’s Lego model or Glenn Seaborg and Georgy Flerov’s drawings of the ‘sea of instability’. The borders of this map are the ‘drip lines’: beyond the neutron drip line, the nucleus kicks out a neutron before it forms; beyond the proton drip line, the same happens for protons. Anything between the drip lines is theoretically possible. Currently, the best guess – and it is only a guess – is that the elements as we know them stretch out to number 172.
RIKEN is hard at work to fill in these blanks. Between 2016 and 2018, the team discovered 73 new nuclides, from isotopes of manganese to erbium. Each contained more neutrons than ever before seen. All of them were created using fission. Rather than trying to avoid the element splitting apart, the Japanese team have revelled in it, blasting uranium at a target made of beryllium – one of the lightest elements – in the hope that the uranium atoms would break into interesting fragments.
While these isotopes may seem pointless, Haba is quick to point out that history says otherwise. ‘Technetium was the first human element made,’ he says, thinking back to how Emilio Segrè found element 43 from one of Ernest Lawrence’s leftovers. At first, it didn’t seem too interesting. ‘Now, technetium is very important for nuclear medicine. Every year, 1 million people use radioisotopes in Japan … [and] the lanthanides are used in magnets or mobile phones. Nobody knew they would be used that way at the time they were discovered. Each element is similar, but each has its own use. Neodymium and lanthanum are similar, but they have their own uses … element 113 [and the other superheavy elements] may have a use too.’
One of Haba’s interests is the superheavy element seaborgium. As with Robert Eichler, Haba and his colleagues are doing rapid-fire chemistry experiments to see how their fleeting products work. RIKEN even have robots to control the process, buying them valuable half-seconds in the world’s fastest chemistry experiments. ‘This is an example,’ Haba says, bringing up a molecular structure on his computer. The seaborgium atom is in the centre of a six-pointed, three-dimensional star. At each point is carbon, then oxygen. It’s a classic chemical structure known as a hexacarbonyl. ‘We produced two seaborgium isotopes, separated them and caught them. Then we added carbon monoxide (CO) here, so we can see if it interacts. Now we know that this hexacarbonyl compound exists. By heating the molecules, we can destroy them and investigate the bond strength between the seaborgium and carbon. We can then compare them with theoretical calculations.’
All of this is again part of rewriting the periodic table. Seaborgium is, supposedly, in the same group as tungsten. But what if it doesn’t behave like tungsten at all? ‘The structure of the periodic table is not going to change,’ Haba stresses. ‘The element is put on the periodic table irrelevant of its properties … but it’s very difficult to get used to the chemistry on this row of the periodic table.’
Not everyone agrees. As with the weight of the kilogram, science has a habit of self-correcting. While an element’s number on the periodic table is static, positions can move about: after all, until Glenn Seaborg came along, uranium had been placed under tungsten, the very position seaborgium occupies today. ‘As a chemist, the usefulness of the periodic table is the periodicity – if shown that these new elements belong in a different group, they should be moved there,’ observes Nancy Stoyer. ‘The periodic table is a living construct.’
If this debate sounds pointless, it’s anything but. By working out how the relativistic effects change the elements, how they stop following rules that science has trusted for centuries, we can work smarter and find new ways to use the elements we have discovered. Remember the search for naturally occurring superheavy elements in the 1970s, with the US and Russian teams launching expeditions into hot springs or the depths of the Gobi Desert to try and find them? Today’s researchers know those searches were looking in all the wrong places: they were basing their hunt on incorrect assumptions about how superheavy elements behave. Years were wasted because we didn’t understand the rules of physical reality.
It’s only by discovering more elements that we can work out what those rules really are.
* * *
RIKEN – like the rest of Japan – isn’t satisfied with one element. Already, its researchers are hunting for more. RILAC is being reconfigured for new experiments; the Nishina Center’s oldest cyclotron has already started the search. Both machines are going to run in parallel to hunt for elements 119 and 120 until they are found. With the new elements’ cross sections predicted to be orders of magnitude lower than nihonium, there’s no point trying cold fusion. Three hits could take centuries. Instead, the RIKEN team have taken a leaf from Oganessian’s playbook and switched to hot fusion.
The reconfiguration of the linear accelerator is the big challenge. It has already cost $40 million just to make the changes required. ‘Not all of the linear accelerator’s parts are superconducting,’ En’yo explains. ‘That lets you go to a lower charge state more effectively. To convert it requires two years, which is why we decided to use the cyclotron as well. The cyclotron isn’t better than the linear accelerator, but with a good ion source we can overcome that and get a reasonable enough intensity to start the 119 search until the linear accelerator is remodelled with a stronger beam.’
This revamped machine will bring new demands. When the team discovered nihonium, shooting zinc into bismuth, the main cost was electricity: zinc and bismuth are cheap. Conversely, hot fusion requires curium targets, created and shipped over especially from Oak Ridge’s HFIR. The search will cost $1 million a year. But it doesn’t matter if the new experiment costs millions or takes another nine years to produce its success: as it has proved time and time again, RIKEN doesn’t back down.
‘We’ll keep running the experiment until we make the discovery,’ En’yo says. ‘Or someone else does.’
The someone else is Yuri Oganessian. While the Japanese were searching for nihonium, he had finished the seventh row of the periodic table.
Notes
1 It’s a source of amusement to the Japanese team that neptunium – which could have been Nishina’s – still ended up as ‘Np’ on the periodic table: it’s the symbol that would have been used for ‘nipponium’.
2 As with the Allied effort, the generals in charge of Ni-Go didn’t really grasp the concept of a nuclear bomb. On one occasion, Nishina’s military liaison, Major General Nobuji, asked him why, if a bomb needed 10kg (22lb) of uranium, they couldn’t just use 10kg of conventional explosives instead?
3 Desert Bus was initially created as a performance art piece by magicians Penn & Teller; even so, each year the marathon game session ‘Desert Bus for Hope’ raises over $500,000.
4 To make matters worse, the IUPAC finding was littered with technical errors; to this day, the Dubna–Livermore group feel robbed. ‘Details matter, and the sloppy IUPAC report is unsatisfactory,’ Mark Stoyer notes. ‘I think all the hard-working scientists in this field have again been done a disservice.’