Superheavy

by Kit Chapman

  Georgy Flerov had baited the Great Bear into atomic action.

  * * *

  The first Russian atomic bomb detonated in August 1949. First Lightning, or RDS-1, was almost identical to Gadget, with the same ‘Fat Man’ bulbous body designed to explode inward and initiate a plutonium chain reaction. The similarity was no fluke: the Russians had stolen the plans. Rather than the Trinity test’s solitary pylon, the Russian test site in the remote steppes of Kazakhstan was surrounded by wooden buildings, a fake subway station, tanks, planes and 1,500 animals to see what would happen. The animals didn’t make it.

  The USSR’s programme had almost as many luminaries as the Manhattan Project. The lead scientist was Kurchatov. Overseeing the whole project was Beria, a man who had already ordered the deaths of thousands, perhaps millions, in Stalin’s purges. Failure wasn’t worth contemplating.

  Flerov was another of those at the test. Shortly after his letter, he had been reassigned (much to his relief) to focus on atomic work. By the war’s end he was a key part of the Soviet nuclear machine, and in mid-1945 found himself in Germany, trying to establish just how far the Nazis had come with atomic research. The answer was ‘not very far’. The German bomb project had never got off the ground, in part thanks to sabotage by Norwegian chemists. The programme that did exist (described by the Allied scientific head as ‘ludicrously small-scale’) had already been picked clean by the British and Americans. Flerov worked to ‘recruit’ any German scientists that remained, now dressed as a colonel in the NKVD – Soviet state security. Unfortunately for Flerov, most of the top German nuclear scientists had already been rounded up by the British and were prisoners in Farm Hall, a manor house on the banks of the river Great Ouse in Cambridgeshire.

  Among the scientific prisoners had been Otto Hahn, the man who, with Lise Meitner, had discovered fission. In 1944 he had won the Nobel Prize for it. Meitner, in one of the great moments of scientific sexism, got nothing (when the Nobel records were later opened, it was revealed she had been nominated and overlooked 48 times). An ardent anti-Nazi, Hahn had stayed in Germany but, unlike many of his fellow prisoners, refused to work on the bomb project. When word reached Farm Hall about the atomic bombing of Hiroshima and Nagasaki, he felt personally responsible and contemplated suicide. Once again, the dark side of science had taken its toll.

  But Germany was a long way from Kazakhstan and yet more bombs. After First Lightning, Flerov was released from his nuclear obligations and began to turn his attention to element discovery. In 1956, after hearing about Al Ghiorso’s discovery of mendelevium, Flerov used Kurchatov’s cyclotron in Moscow to bombard plutonium with oxygen in an attempt to make element 102. Perhaps he even succeeded, although even Flerov admitted the results were inconclusive.

  In Georgy Flerov, the Soviets had discovered their own element mastermind. But if he was going to compete with the Americans, he needed a laboratory that could rival Berkeley.

  * * *

  The Joint Institute for Nuclear Research (JINR) sits at the heart of Dubna, a small town two hours’ drive from Moscow. To get there involves a trip down a long, single-lane carriageway that slices through heavy pine forests and cuts past a T-34 tank parked to mark the point where the Axis invasion was stopped 75 years ago. You can begin to feel the history of the place before you arrive.

  Dubna is a naukograd, one of Russia’s dedicated science hubs. Entry is past a giant metal sculpture proclaiming the town’s name – a cast-steel version of the Hollywood sign – and banners immortalising its scientific heroes. The Volga River cuts the settlement in half. On the south bank, where the Volga meets the Moscow canal, a 25m (80ft)-tall statue of Lenin keeps a lonely vigil. Originally, it was accompanied by a similar bust of Stalin, but that was quietly dismantled shortly after the dictator’s death.

  By all accounts, Dubna hasn’t changed much since JINR was established, save for a few Western touches that have crept in since the Iron Curtain fell: a McDonald’s, a small supermarket, a fantasy-themed hotel. It’s easy to overlook these capitalist trappings and imagine the town the first scientists must have seen when they arrived in the 1950s, drawn from across the communist world to create a centre of nuclear excellence.

  The man I’m here to see was one of those arrivals. He has been here, save for lectures abroad, ever since. His name is Yuri Oganessian, and he is currently the only living person to have an element named after him.

  I’ve seen photos of Oganessian as he was when he started work at JINR: a fresh-faced 28-year-old of Armenian descent, short in stature, with classical features, his hair slicked down and a mischievous grin always playing at the corner of his lips. As a young man, Oganessian initially wanted to be an architect, but his penchant for science brought him to the Moscow Engineering Physics Institute. Here, it soon became clear Oganessian had a gift for organising the large-scale projects that would drive post-war science. He had a creative, eager mind that could solve problems; and, more importantly, he had a talent for bringing the right people together to realise his ideas. Upon graduation, Oganessian found himself wooed by the greatest minds in the USSR. After giving his future some thought, he elected to join Flerov as his chief engineer.

  It was a typically bold appointment by Flerov – the young Armenian didn’t even have a PhD. The job interview was equally bizarre. Flerov sat Oganessian down and chatted to him for an hour without asking a single question about science. ‘From the first meeting with him, there was a conversation,’ Oganessian told the YouTube channel Periodic Videos. ‘He didn’t ask me about physics. He just asked me what I liked in life. Sport. If I liked the theatre, music, other things. It was just a conversation like that. Then he said “OK, OK, I’m satisfied. Thank you very much – I’ll take you in my group.”’

  Apart from the town of their birth (Oganessian was also from Rostov-on-Don), the two men had little in common. Yet, as with Seaborg and Ghiorso, they were the perfect fit. ‘This programme of superheavy elements was so fantastic for a young guy,’ Oganessian recalls. ‘If I had the chance to start again now, I would do it this way again.’

  The feeling of respect was mutual. Flerov had in mind an audacious plan that needed someone of Oganessian’s brilliance. Tired of Berkeley’s domination, Flerov planned to join the race for the superheavy elements and had designed a machine – a new cyclotron – he believed could beat the Americans. Oganessian was going to build it.

  The entry to JINR is at the end of a muddy road across a ruined level crossing (the warning siren always on, the barrier always open). A small checkpoint guards the entrance, where my passes are checked and authorised. A moment later, stepping through a small wooden door, I’m standing on the main boulevard of Russia’s premier science facility. Some of the buildings have a fresh coat of paint and new wings as they have expanded; others have boarded-up doors and shattered windows, and seem to be in a state of general dilapidation. JINR, my guide Nikolay Aksenov explains, comprises seven laboratories, all looking at different areas of nuclear science. Funding depends on success – and some labs have been more successful than others.

  The Flerov Laboratory of Nuclear Reactions is the second building on the right. It is clearly one of the more affluent laboratories, although the building itself is a blockish, whitewashed complex that takes the same form as all the others. Outside, 0.5m (2ft) metal dewars – pots containing liquid nitrogen – have been stacked ready for use. The caps to the dewars were lost a long time ago; these days, empty baked bean cans do the job.

  Aksenov leads the way into the building, up the stairs to the first floor, through a secretary’s office and into a long, oak-panelled room dominated by a massive conference table stacked with magazines, reports and scientific papers. At one end, rising from his desk, is the lab director, Sergey Dmitriev; standing next to him and smiling warmly is Oganessian – the man who, with Flerov, put JINR on the map. Still surprisingly spry for someone in his eighties, he hurries over to greet me in flawless English. We’ve never met before, but he sh
akes hands like I’m an old friend, promising to catch up later before heading to his office. It’s hard to get over the thought that I’ve just met one of the most influential scientists in the world.

  Dmitriev is also effusive in his welcome. He directs my gaze to a large plasma screen positioned on the wall behind me. On it is a live feed from the new cyclotron under construction, a few hundred yards down the road. It’s a strangely still image: the only activity on screen is an old woman with a mop and bucket, cleaning around what looks like a giant, 6m (15ft)-wide lump of circular metal on the floor. It takes a moment to realise that these are the two dees, the electrodes that form the beating heart of a cyclotron. Once finished, it will be one of the most powerful pieces of scientific equipment in the world, joining the other five cyclotrons operated by the Flerov lab team. Currently it’s still waiting on its other vital components, not least the magnet that will cause those ions to spin.

  ‘I can’t wait to see one in action,’ I say. I never did see the cyclotron at Berkeley – the sticky rib sandwich laid on by Jacklyn Gates distracted me.

  Dmitriev smiles. ‘OK, let’s go. Now is a good time to visit the main cyclotron. It works 24 hours a day and there’s a queue to use it. But at the moment we can get in.’

  Today U400M – the U stands for uskoritel, or accelerator – is being used by a private space company, bombarding their satellites with ions to simulate cosmic rays. The machine is only turned off for two weeks a year, Aksenov explains on the way, as Dmitriev leads us down a flight of stairs and along an unmarked corridor. That’s because at the height of summer, the water taken from the Volga is too hot to act as a coolant. ‘That’s when the engineers can make repairs,’ Aksenov says. ‘There’s another reason we do it then too: we can all take a summer vacation.’

  Down the corridor, past one turn and through a small control room bedecked with monitors, readouts and flashing buttons, we arrive. The sight is like nothing else in the world. In principle, the U400M is exactly the same as the first generation of cyclotrons: an ion machine gun. It just happens to be a machine gun the size of a house that fires 6 trillion bullets per second.

  When visitors saw Lawrence’s 1939 cyclotron they called it a ‘truly colossal machine’. It weighed 220t. U400M weighs 2,100t. At first it looks like a power plant – a large, cold concrete box with a humming machine in the centre, pipes shooting off everywhere guarded by emergency valves and metal walkways arranged to step over the crucial equipment. Yet glancing up at the huge contraption that dominates the room, you can just make out the familiar zinc battery appearance of the cyclotron’s dees, sandwiched under a huge magnetic arch as if they were gripped by a clamp.

  It’s loud. The whole thing hums constantly as its electromagnet keeps the beam where it needs to go ... valves occasionally hiss as they release pressurised steam ... coolant rumbles from somewhere inside. White beards of frost appear at key joints where the liquid nitrogen is added from the baked bean can dewars. This coolant, along with water from the Volga, is essential. As a cyclotron demands an electrically charged projectile, atoms used in the beam have to be heated to strip them of their electrons. This means that U400M shoots an intensely hot plasma – electrically charged gas – of around 600 °C.1

  ‘This is all pretty typical equipment,’ Aksenov says, pointing around the room. ‘It’s just of very good construction. Pumps, pipelines, cooling water. The injection of ions is here, accelerator here, this is the beam line.’ He traces his finger along the route of a pipe that weaves its way across the floor before vanishing into a solid wall. ‘You focus it on a target in there. We hide the target; these blocks are to isolate the radiation, so this room is always at background radiation levels.’

  Aksenov is being modest. The machine is a modern marvel: it helped discover five chemical elements.

  * * *

  U400M is a world away from JINR’s first effort, the U300. Built to custom specifications in Leningrad and 3m (10ft) in diameter, Flerov had ordered a machine to match anything else in the world. Handing the plans to Oganessian, he had tasked his young assistant with turning his vision into a reality.

  At first, progress was slow: none of the Russian team had any experience building a cyclotron. ‘One had to be a pioneer in almost everything,’ the JINR records state, ‘and the only guide was one’s academic knowledge and intuition. Lack of coordination and mistakes were inevitable.’ Yet in Oganessian, Flerov had chosen the perfect leader. Somehow, the young Armenian kept the team together, preventing conflicts, delegating jobs and solving problems before they derailed the project. ‘It was largely Oganessian’s skills,’ the record continues, ‘[that ensured] the success of its accelerator complex.’ On completion, it was probably the best machine in the world for discovering new elements, capable of accelerating ions as heavy as neon.

  The Berkeley element hunters also had a new toy to play with. At the suggestion of Luis Alvarez, the laboratory had collaborated with Yale University to build a heavy ion linear accelerator (HILAC), hauling its parts up the Blackberry Canyon pass on flatbed trucks. In April 1957, HILAC had begun operation. Now the Americans had the ability to shoot heavier ion beams too.

  Figure 5 Transporting part of the HILAC to Lawrence Berkeley Laboratory, 1956.

  Sadly, Lawrence would never see the fruits of Berkeley’s latest ‘Big Science’ scheme. In 1958 President Eisenhower asked him to attend nuclear treaty talks in Switzerland. Despite having a flare-up of ulcerative colitis, Lawrence agreed. He fell ill and died shortly after his return to the US. Less than a month later, the University of California decided to name their two nuclear research sites after him: the Lawrence Radiation Laboratories at Berkeley and Livermore were formed.2

  With the completion of U300 and HILAC, the US and USSR teams were evenly matched. Both had cutting-edge equipment, the resources of a superpower behind them, and skilled leaders capable of element discovery.

  It was the wider Cold War in microcosm – and it would prove to be just as divisive.

  Notes

  1 Calcium usually turns to gas at around 1,484 °C, but the system is kept in a vacuum, which lowers the boiling point.

  2 In 1971 they became Lawrence Berkeley Laboratory and Lawrence Livermore Laboratory; in 1995 they both got ‘National’ in their titles.

  CHAPTER TEN

  The East and the West

  On 3 July 1959, a little after lunch, men and women rushed out of the Berkeley HILAC building fleeing for their lives. They had seen minor lab accidents before. They had heard fire alarms go off in error or thanks to Al Ghiorso’s tinkering. But this was the real deal. The entire building had been flooded with radioactive dust. Inhalation could mean death.

  The lab had been unusually busy, with 27 people inside; half of the potential victims were plumbers, there to work on a tank. The first 26 evacuees to emerge were met by the Berkeley safety team, who took swabs from people’s nostrils to determine their exposure. Those contaminated were ordered to strip naked. Their clothes were then tagged, placed in cement sacks and destroyed. One member of staff, Vic Viola, decided to take decontamination a step further and darted into a nearby lab to dunk his hair in its sink (Viola does not remember this, and insists he had a crew cut at the time). Clean smocks were provided to preserve dignity and stave off the chill Bay Area winds.

  Finally, the last evacuee, Ghiorso, walked out of the lab. He was wearing a respirator, overalls, booties and gloves. Without a word he stripped them off, walked toward the nearest decontamination shower and let the icy water wash over him. The Lawrence Radiation Laboratory had just experienced its first major accident.

  The US team had been attempting to find element 102, still convinced the Swedish claim was an error. But beyond mendelevium, the potential half-lives and cross sections of elements were tiny (the atoms were larger and more unstable), and there was only so fast you could drive a Volkswagen Beetle. To compensate for the capricious nature of his atomic hunt, Ghiorso had turned to a new method of eleme
nt detection. Rather than look for the element itself, he was looking for its daughters: the known elements it would produce through alpha decay. Element 102 would decay two places back on the periodic table into fermium. When creating element 102 through fusion, all he needed to do was find fermium in his detector and the discovery would be proven.

  This wasn’t as straightforward as it sounds. Alpha radiation follows Isaac Newton’s laws of motion: every time an atom decays and throws off an alpha particle, the nucleus also pings off in the opposite direction. If Ghiorso just used a catcher foil, as he had for mendelevium, he would never find anything: any element produced would fly off his foil the moment it decayed. Ever the inventor, Ghiorso soon had a solution. He needed to set up the element hunter’s equivalent of a pool trick shot.

  First, as with every other experiment, the ion beam would hit the target (in this case, curium was bombarded with carbon ions). If fusion occurred, the newly formed element 102 would be thrown forward by the beam into the end of the accelerator just like before. Here came the clever part. At the back of the chamber was a moving, negatively charged conveyor belt. Any element 102 produced would immediately be drawn to and deposited on the belt, which would then drag the element out of the target chamber and under a sheet of catcher foil. If element 102 was caught on the belt and decayed, the newly produced fermium would be flicked onto the waiting sheet of foil. Ghiorso dubbed his new toy Hades.1

  The machine had been an immediate success. In 1958 Ghiorso reported that he had detected traces of fermium, which could only have come from element 102. Within a year, the Berkeley team had more data to back up their findings. It was, in Ghiorso’s opinion, stronger evidence than anything the Swedish had come up with – he just needed a few more experiments to be sure.

  It was during those final tests that the accident had occurred. Hades was filled with helium, which served to remove all the fission products created during bombardment and get rid of unwanted radioactive noise. This required regular flushing of the system to remove any unwanted trapped gases, much like bleeding a giant radiator. During a flush, the curium target – spitting out deadly alpha particles – was left in the machine.