Element hunter Yuri Oganessian on creating new chemical elements (20-03-2016)

Russian nuclear physicist Yuri Oganessian from the world renowned nuclear lab in Russia's Dubna welcomes the first non-Russian film crew at his lab, talking on how to find new chemical elements.

More videos with Yuri Oganessian



No video? Please use the latest version of Safari, Chrome or Firefox. Internet Explorer might cause problems.
automatically generated captions
00:00:01 Could you tell me what is so unique of this institute?
00:00:07 This is the Joint Institute for Nuclear Research, the JINR.
00:00:12 It celebrates its 60th anniversary this year.
00:00:18 Accidentally...
00:00:22 ...I came to work for the institute the year it was established.
00:00:27 And I've been working here ever since.
00:00:33 Its mission is...
00:00:35 ...to research fundamental issues in nuclear physics...
00:00:41 ...in high energy physics...
00:00:44 ...or particle physics as we call it...
00:00:46 ...and in condensed matter physics.
00:00:49 We do research in theoretical physics...
00:00:52 ...which is applicable to every area I mentioned.
00:00:56 We have got departments of mathematical studies and IT...
00:00:59 ...and everything else scientists would need nowadays.
00:01:08 JINR is an experimental facility.
00:01:10 We have got powerful research tools...
00:01:14 ...including smaller, bigger and super powerful particle accelerators...
00:01:19 ...a nuclear reactor...
00:01:21 ...and a lot of other instruments.
00:01:28 18 countries...
00:01:31 ...are...
00:01:34 ...JINR Member States.
00:01:36 The Institute receives funding from its Member States.
00:01:41 The JINR highest governing body is the Committee of Plenipotentiaries...
00:01:46 ...who are appointed by Prime Ministers of the Member States.
00:01:54 The JINR Scientific Council defines the science policy of the institute.
00:02:00 The Scientific Council meets twice a year.
00:02:03 The members of the Council are prominent physicists...
00:02:10 ...in all the areas that I mentioned earlier.
00:02:14 They don't have to work for JINR. They are experts.
00:02:20 In between the meetings of the Scientific Council...
00:02:24 we work in Advisory Committees for Nuclear Physics...
00:02:27 ...Particle Physics and Condensed Matter Physics.
00:02:31 This is basically the way JINR operates.
00:02:35 Which countries are we talking about?
00:02:41 These 18 countries. Can you give some examples?
00:02:45 Yes, these countries are JINR Member States.
00:02:50 There are also some countries which are JINR Associated Member States.
00:02:56 The Associated Member States are interested in specific areas of physics.
00:03:02 The JINR Member States include...
00:03:09 ...Czech Republic, Bulgaria...
00:03:12 ...Romania, Poland.
00:03:14 The East European countries.
00:03:16 Other JINR Member States include Vietnam...
00:03:21 ...Mongolia...
00:03:24 ...Cuba.
00:03:28 The Associated Member States are Germany, South Africa...
00:03:34 Italian physicists are very enthusiastic about this cooperation.
00:03:38 American physicists work in one of our Laboratories.
00:03:42 JINR is deeply rooted in the system of international cooperation.
00:03:49 I would like to mention...
00:03:52 ...that this system of international cooperation...
00:03:55 ...was established back in the Soviet era.
00:03:59 Back then the international cooperation was not very active.
00:04:03 Despite that fact, JINR was granted this advantage.
00:04:08 We ran ahead of many other institutions.
00:04:13 And even nowadays the legacy of those times...
00:04:17 ...lives on and we build on it in our work.
00:04:20 This is why...
00:04:22 ...I mean...
00:04:23 ...JINR is well-known for its accomplishments...
00:04:27 ...as well as for its deep integration into the world science.
00:04:31 Numerous teams of our scientists work in CERN...
00:04:36 ...in the US Brookhaven National Laboratory...
00:04:42 ...in Fermilab and other research centers.
00:04:45 Foreign physicists come to JINR to use our particle accelerators.
00:04:52 This is a true spirit...
00:04:55 ...of science, which should be international.
00:05:04 And what is your role in it?
00:05:07 What is your role in the Institute?
00:05:10 What is your function?
00:05:12 We focus on three main areas of research:
00:05:17 particle or high energy physics, nuclear physics...
00:05:21 ...and condensed matter physics.
00:05:28 I am mostly involved in the nuclear physics research.
00:05:36 We use a wide range of accelerators in our programs.
00:05:41 We run a nuclear reactor...
00:05:43 ...and an accelerator of heavy ions in the neighboring laboratory.
00:05:48 Historically, physicists use accelerators of heavy ions...
00:05:52 ...for their research in nuclear physics.
00:05:55 I work in the Laboratory of Nuclear Reactions.
00:06:01 Essentially, we study the physics of heavy ions.
00:06:05 It became a separate area of physics soon after I came to work for JINR.
00:06:10 Back then, there were just two labs in the world working in this field.
00:06:14 One of them was located here.
00:06:17 The other one was in Berkeley, California.
00:06:21 But when it became obvious...
00:06:26 ...that we obtain so much scientific data in this area of physics...
00:06:32 ...many countries established new laboratories.
00:06:38 Including the USA, France, Germany, Poland.
00:06:46 There was one in Groningen, too. To name a few. And then...
00:06:51 ...National Laboratories of Heavy Ions were established.
00:06:56 Later we saw International Laboratories which run large colliders.
00:07:01 The CERN large collider accelerates both protons and heavy ions.
00:07:08 We are going to build a large heavy ion collider, too.
00:07:12 This is the area of research...
00:07:17 ...where we use...
00:07:19 ...very heavy particles to bombard the targets.
00:07:25 This area of physics is gradually developing.
00:07:29 There are large colliders in the USA, Japan and China.
00:07:37 Nowadays, nuclear physicists widely use...
00:07:42 ...this method to research the atomic nuclei.
00:07:46 This is something we do here, too.
00:07:50 Of course, this is a very complex subject.
00:07:53 We have to research the ways particles interact at various energy levels...
00:08:01 ...and the new particles and new nuclei they generate in this interaction.
00:08:10 And what is so different about these new nuclei?
00:08:19 One of our missions...
00:08:23 ...is to produce the heaviest nuclei...
00:08:28 ...which don't exist in nature.
00:08:33 We want to advance as much as possible.
00:08:37 We want to know the maximum possible atomic mass.
00:08:44 What is the limit?
00:08:47 What is the heaviest possible atomic nucleus?
00:08:50 It is interesting...
00:08:54 ...because if we want to answer this question...
00:08:58 ...we must build on everything we already know about the atomic nucleus.
00:09:03 Any uncertainty in our knowledge may generate multiple answers.
00:09:09 One of them would be correct. And the rest should be discarded.
00:09:15 Which in turn would oblige us to review earlier theoretical models.
00:09:20 This is sort of a sharp point which we can use...
00:09:23 ...to test out theories and our knowledge...
00:09:28 ...of atomic nuclei, nuclear forces, and nuclear transmutations.
00:09:34 For quite a while now...
00:09:39 ...physicists take great interest in this thing.
00:09:43 We want to answer this question.
00:09:45 I believe we wanted that even before the era of nuclear physics.
00:09:49 The man always eagerly probed for the limits of the material world.
00:09:57 Each time he interpreted his discoveries...
00:10:00 ...depending on his perception of the world around him.
00:10:05 Probably, the first deep analysis of the material world...
00:10:11 ...was performed at the end of the 19th and at the beginning of the 20th century.
00:10:17 Dmitri Mendeleev was the first person...
00:10:22 ...to put the elements you can find in soil in a certain order.
00:10:30 He created his periodic table of elements.
00:10:33 The chemical properties of elements can be put in a certain order.
00:10:39 The inner structure of the elements...
00:10:43 ...which we didn't know about back then revealed itself in a certain way.
00:10:49 Then we went further and developed the quantum mechanics.
00:10:55 Einstein, Rutherford, a model of an atomic nucleus.
00:10:58 The physics gained a momentum and started to develop really fast.
00:11:02 And it made us even more eager to go to the limit.
00:11:08 That was the golden age of physics when one discovery followed the other.
00:11:15 Every discovery transformed our perception of the world. And every time...
00:11:20 ...this new perception could have been tested...
00:11:26 ...on the nuclei in their excited state.
00:11:31 But we had to excite the nuclei which was always hard.
00:11:37 We don't get excited that easily either. The same thing here.
00:11:46 This is why we established the laboratory...
00:11:52 ...to research the ultimate limit of the nuclear mass.
00:11:58 We didn't do it from scratch.
00:12:01 It all started during World War II...
00:12:07 ...when the US scientists produced plutonium. It is a man-made element.
00:12:13 It was synthesized back in 1940.
00:12:19 By Glenn Seaborg and Philip Abelson.
00:12:22 The US built a nuclear reactor in 1943.
00:12:26 And it produced considerable amounts of plutonium.
00:12:32 We know that that plutonium was used to make a nuclear bomb.
00:12:36 We should also keep in mind that later the energy of plutonium was used...
00:12:40 ...for civilian purposes, too.
00:12:43 We used it to generate electricity and for many other things.
00:12:52 The atomic number of plutonium is 94.
00:12:57 The last naturally occurring element is uranium. Its number is 92.
00:13:01 They are just two digits away from each other.
00:13:06 But these two steps are the steps into the realm...
00:13:09 ...of elements which don't occur in nature and which we can only synthesize.
00:13:17 I wanted to draw your attention to the fact...
00:13:20 ...that these are also two steps into the past.
00:13:23 Because 4.5 billion years ago...
00:13:27 ...when the Earth was formed, plutonium was there.
00:13:30 Its half-life is 25.000 years. This is why it decayed before we could trace it.
00:13:37 But in the 20th century...
00:13:41 ...we found a way to produce it in the lab and explore its properties.
00:13:45 We developed a plutonium industry.
00:13:48 We breed hundreds of tons of plutonium.
00:13:56 We found the ways to put this element to use.
00:13:59 And we took just 2 steps. But why not take 3 or 4 or 5 steps?
00:14:05 And we started to do so.
00:14:08 6, 7, 8, 9, 10 steps.
00:14:14 Yeah, we continue.
00:14:17 Element 93. Could you start there?
00:14:21 Yes, this is...
00:14:26 Well...
00:14:28 We took 2 steps to produce plutonium with the atomic number 94.
00:14:33 Then we took 3, 4, 5, and 6 steps.
00:14:38 And finally, we approached the element...
00:14:43 ...which could not exist, theoretically.
00:14:49 But it does exist.
00:14:51 We went further and produced the next one. And the next one.
00:14:56 That meant there was something wrong with the classical theory.
00:15:01 It gave us an incorrect prediction of the limit.
00:15:05 The classical theory rules out...
00:15:09 ...elements with atomic numbers over 100.
00:15:13 But we produced elements with atomic numbers 102...
00:15:17 ...103, and 104.
00:15:21 Back in 1964.
00:15:25 That was not that long ago.
00:15:30 We knew that we had to find some explanation...
00:15:34 ...of this fact and many others...
00:15:37 ...which didn't fit in the old classical theory.
00:15:44 The old theory proved very useful.
00:15:47 It helped us explain a lot of things.
00:15:49 But it could not predict the limit. The predicted limit was incorrect.
00:15:54 And so, we had to develop a new theory...
00:15:58 ...that would help us understand...
00:16:01 First of all, it had to be the same efficient in describing the world.
00:16:04 But also, it had to explain why we can go beyond the limits of the classical theory.
00:16:12 We found an explanation...
00:16:16 ...in 1969.
00:16:21 The new theory gave us an opportunity to produce new elements.
00:16:26 But their half-life would be shorter and shorter with every new element.
00:16:34 Although it also predicts that the elements...
00:16:37 ...with large atomic numbers may have longer half-life again.
00:16:40 I wonder if you could imagine an island on the half-life timeline.
00:16:45 That would be an island made of very heavy elements.
00:16:49 Super-heavy elements as we call them.
00:16:52 And they will exist significantly longer...
00:16:56 ...than their lighter precursors.
00:17:01 They are placed in the periodic table...
00:17:05 ...where no elements can exist in accordance with the old theory.
00:17:10 But the new theory gives us this opportunity.
00:17:13 Hopefully the new one is correct.
00:17:16 Because it can also be wrong.
00:17:19 These are postulated elements.
00:17:24 We should prove if they exist or not.
00:17:28 At some point we will have to say yes or no.
00:17:36 And we have to do much work to do so.
00:17:42 We have to try and synthesize these elements.
00:17:48 And I don't mean the element with the atomic number 94.
00:17:52 Or 104. Or even 114.
00:17:57 We also have to explore their properties.
00:18:01 So...
00:18:02 How do you do that? I mean, making an element?
00:18:05 Yes, and all the best physicists and experimentalists came together...
00:18:10 ...to try and solve this problem.
00:18:17 The first experiment was conducted in 1970. Just a year later.
00:18:24 In France.
00:18:27 I was invited to participate in it in the Joliot-Curie Institute.
00:18:30 I took part in this experiment and we got no results.
00:18:35 The physicists put in great efforts to discover these elements.
00:18:39 They used powerful reactors to search for super-heavy elements.
00:18:46 We tried to trace them in the nuclear explosions.
00:18:50 We looked for them in nature.
00:18:53 In cosmic rays.
00:18:55 In various chemical reactions.
00:18:58 In nuclear reactions, which involved heavy particles and neutrons.
00:19:04 Unfortunately, those experiments...
00:19:08 ...yielded no results.
00:19:14 We launched this program...
00:19:19 ...back in 1970.
00:19:25 And I should say...
00:19:28 ...that we hadn't achieved any results by 1990.
00:19:34 And no results by 1995.
00:19:37 And we conducted those experiments in the biggest research centers...
00:19:42 ...in the US, in Dubna, Russia and France.
00:19:49 That was quite a difficult moment.
00:19:56 What should we do? We...
00:20:00 We couldn't produce any new elements.
00:20:03 And we could neither prove nor rule out their existence.
00:20:07 Is the theory incorrect again?
00:20:11 What if these elements don't exist?
00:20:14 But then we would have to review the theory once again.
00:20:18 The old one didn't work. The new one didn't work either.
00:20:23 So, we need one which would explain our earlier results...
00:20:27 ...and postulate that these super-heavy elements can't exist.
00:20:31 That was difficult. Because there were too many things to explain.
00:20:37 The things we had done in the nuclear physics for years.
00:20:44 That was quite disappointing.
00:20:49 Or what if we just didn't know how to produce these elements?
00:20:54 What if our instruments were not powerful enough to produce them?
00:21:00 That moment I thought...
00:21:05 And my colleagues thought that too.
00:21:08 Most probably we didn't have tools to produce those elements.
00:21:15 Should we change our philosophy then? What if we set wrong objectives?
00:21:21 But then we synthesized some new elements before.
00:21:24 Those were not super-heavy ones. Probably that's where the difference lies.
00:21:30 We had to raise the bar significantly.
00:21:33 We decided to use artificial material to make our target.
00:21:39 That meant we had to use powerful reactors...
00:21:44 ...to breed the material for our targets.
00:21:47 And we had to radically change the way...
00:21:51 ...we choose...
00:21:54 ...the bombarding nuclei.
00:21:57 We had to find a new acceleration mode and a new ion source.
00:22:03 We had to do some hard work.
00:22:08 And now I would like to tell you...
00:22:12 ...that at the end of the 20th century...
00:22:18 ...and at the beginning of the 21st century the people of science understood...
00:22:23 ...that if they wanted to accomplish some ultimate missions...
00:22:30 ...they would have to work together as a team.
00:22:34 Imagine, a group of scientists is working somewhere far away...
00:22:38 ...in the other part of the world.
00:22:41 And they achieved good results with their equipment.
00:22:44 Another team somewhere in France...
00:22:48 ...got some results with other instruments.
00:22:52 But when we put their efforts together...
00:22:56 ...and utilize...
00:22:59 ...all the scientific accomplishments of the mankind...
00:23:05 we may get to an entirely new level.
00:23:09 And so, we decided to opt for this approach.
00:23:12 We brought an ion source from France...
00:23:15 ...and redesigned it to our needs.
00:23:18 We involved our American colleagues who ran a powerful reactor.
00:23:23 We asked them to breed this material for us.
00:23:27 We upgraded our own accelerator.
00:23:33 We developed a new technology to accelerate the ions of calcium-48.
00:23:39 We devised a whole new installation.
00:23:42 But then we didn't like it and we did it all over again.
00:23:46 We didn't like the new set-up either.
00:23:52 And so, we started to modify it once again.
00:23:58 At the very end of 1999...
00:24:05 ...in winter we conducted our first experiment.
00:24:10 The plutonium bred at the reactor in the US...
00:24:14 ...had to be bombarded by calcium-48, produced by the separator in the Urals...
00:24:21 ...in the ion source we received from France...
00:24:26 ...installed at the new separator system which was designed here.
00:24:30 And that was the very first time when we saw...
00:24:35 ...the fission of the element with the atomic number 114.
00:24:41 The fission took quite long.
00:24:44 You could even look at the watch.
00:24:46 Element 114 was stable for two seconds before decaying into Element 112.
00:24:52 Element 112 was stable for half a minute before decaying into Element 114.
00:24:56 I mean, Element 110. And Element 110 decayed spontaneously.
00:25:00 That was...
00:25:03 ...extremely unusual. Because the elements which were synthesized earlier...
00:25:08 ...like Elements 108 or 109, their half-life was just several milliseconds long.
00:25:13 Or several microseconds. Compared to seconds for Element 114.
00:25:17 And so, we saw that our latest theory was correct...
00:25:22 ...in the estimation of the half-life of these elements.
00:25:26 We felt truly encouraged.
00:25:29 After that experiment...
00:25:34 ...we lived another 10 years of our lives.
00:25:38 We got more confident and relaxed. We knew we would get the results.
00:25:42 We upgraded the sources and the accelerators and the equipment.
00:25:48 Our American colleagues bred more material for our new targets.
00:25:52 This is the way we produced a whole range of new elements.
00:25:58 We took full advantage of the reactor.
00:26:03 We took full advantage of our accelerator.
00:26:09 As a result, we produced Elements 113, 114, 115...
00:26:14 ...116, 117, and 118. The six elements.
00:26:21 You can ask me why six and not seven.
00:26:26 If the reactor could produce a heavier target...
00:26:29 ...we would have synthesized seven elements.
00:26:33 With an even heavier one we could produce eight of them.
00:26:35 The reactor has its limits.
00:26:38 Even the most powerful of all the reactors...
00:26:41 ...can't produce a target...
00:26:44 ...with the atomic number 99. The one with the atomic number 98...
00:26:47 ...gives us Element 118. But we can't have a target with the atomic number 99.
00:26:52 As a result, by now...
00:26:55 ...we can benefit from everything...
00:27:00 ...which was developed by our predecessors in different areas of physics.
00:27:04 In the physics of nuclear reactors and the accelerators...
00:27:08 ...and the physics of nuclear reactions. We did our thing. In this way, of course...
00:27:14 ...it is very good that we did it. But it is not only us...
00:27:19 ...who did it. This is also an accomplishment...
00:27:22 ...of many generations of physicists before us.
00:27:26 So...
00:27:29 Could you explain me...
00:27:34 ...an element? What is an element?
00:27:38 What is... - An element?
00:27:40 Could you explain it? What is an element? The element in itself? What is it?
00:27:46 We are talking about elements now.
00:27:50 But in fact, we produce atomic nuclei.
00:27:56 Whilst an element is an atom.
00:27:59 We trigger a nuclear reaction in order to modify the nucleus.
00:28:04 We convert a nucleus into a new one.
00:28:20 I am sorry. - No problem.
00:28:44 So I'll ask... No problem.
00:28:46 ...the question again. What is an element?
00:28:49 We convert a nucleus into a new one.
00:28:53 And when the new nucleus is synthesized, it attracts electrons.
00:28:58 And then this is an atom. This is a new element.
00:29:03 And then we can explore the chemical properties of this element.
00:29:09 Since we can explore the chemical properties, chemists come into play.
00:29:15 Let us remember the table of elements now.
00:29:18 This table is called periodic.
00:29:22 So we should place this new element...
00:29:25 ...in the table where its expected chemical properties...
00:29:31 ...in accordance with the fundamental Periodic Law...
00:29:36 ...would match this very position. What do I mean to say?
00:29:40 If we produce Element 112, it should be placed below mercury.
00:29:48 If you produce Element 114, it should be placed in a column under lead.
00:29:54 If you produce Element 118, it should be placed under radon.
00:30:00 This is what the Periodic Law is about.
00:30:04 But then we have to do one more thing.
00:30:07 We must check if these new elements are subject to the Periodic Law.
00:30:11 We have to conduct chemical experiments.
00:30:14 Not physical but chemical ones.
00:30:16 And we have to work with atoms instead of atomic nuclei.
00:30:19 Otherwise we can't answer this question.
00:30:23 Just imagine. Thanks to the fact...
00:30:29 ...that these new super-heavy elements exist long enough...
00:30:35 ...seconds instead of milliseconds...
00:30:38 we can conduct these experiments. And we did that.
00:30:41 We carry out these experiments nowadays, too.
00:30:45 The experiments proved that the placement of the new elements...
00:30:48 ...was correct.
00:30:49 Though their properties were a little bit different...
00:30:54 ...from those predicted...
00:30:58 ...by the Periodic Law.
00:31:02 These differences are caused by relativistic effects.
00:31:09 The electrons of a super-heavy atom are also very heavy.
00:31:13 We should keep that in mind when we explore the chemical properties.
00:31:19 The relativistic effects were always there with heavy elements.
00:31:25 I should mention that gold is what it is because of relativistic effects.
00:31:30 And mercury is a liquid metal because of relativistic effects.
00:31:34 With super-heavy elements these effects should be even more evident.
00:31:39 And they are. But still these elements can be placed in the table...
00:31:44 ...as predicted by Mendeleev and his Periodic Law.
00:31:51 And what can we do with the new elements?
00:31:54 What is it for the humanity? What does it mean what you are doing?
00:31:58 This is something I wanted to mention. In fact, it doesn't mean a thing.
00:32:04 Nothing. Because we can produce these elements...
00:32:08 ...in ultralow quantities. We can produce their atoms.
00:32:11 We are happy to produce an atom a day.
00:32:18 Or even an atom a month if we are talking about rare elements.
00:32:25 But anyway, we are sure that we produce them.
00:32:29 Because we record events which prove it.
00:32:35 We have got lots of things to do...
00:32:39 ...to thoroughly explore their properties.
00:32:43 This is why we should produce more.
00:32:46 10 times or even 100 times more. 1000 times more.
00:32:49 Then we could launch full-scale research programs.
00:32:55 And they won't be anything exotic. Just regular research work.
00:33:03 But if you want to do that...
00:33:06 ...you should take a pause and try to figure out what you should do next.
00:33:12 You can't do any research if you produce an atom a day.
00:33:16 Your life would be too short for that.
00:33:23 This is why we came up with a surprising question.
00:33:26 10 years later...
00:33:30 10 years after we started experiments with super-heavy elements.
00:33:36 What would be the way we would do the same things today?
00:33:41 Not 10 years ago, but today.
00:33:44 We produced some super-heavy elements. We know their properties.
00:33:49 We know the ways to produce them.
00:33:52 And we know the ways you can never produce them.
00:33:57 This is one side of this coin. We know something. We got some knowledge.
00:34:02 But on the other hand, we saw major technological advances in those years.
00:34:08 We have got different accelerators and different sources now.
00:34:13 And the computers are different.
00:34:15 Everything has changed a lot in those 10 years.
00:34:19 If we use our knowledge...
00:34:22 ...on the technological innovations of the previous 10 years...
00:34:28 ...we can produce 100 times more of these elements quantity-wise.
00:34:35 And we decided to build a factory to produce super-heavy elements.
00:34:40 We are building this laboratory now.
00:34:45 We hope to start the experiments at the end of next year.
00:34:50 Naturally, those experiments will be different from what we are doing now.
00:34:55 We don't know what these experiments will be.
00:35:00 Everything can change on the way. This is what science is about.
00:35:04 But something is clear.
00:35:08 We can use this facility...
00:35:12 ...to conduct 2-3 experiments a year.
00:35:14 And each of them will include thousands of events.
00:35:19 And then we will probably see something we can't see now...
00:35:25 ...because we don't have enough of these exotic elements.
00:35:31 This is our future.
00:35:34 But it means also that at this point we don't know yet...
00:35:39 ...what we can do with the new elements? Is that correct?
00:35:43 Yes, now...
00:35:44 At this moment, these new elements do nothing else...
00:35:47 ...but give us some fundamental scientific data.
00:35:52 They help us confirm...
00:35:57 ...that our knowledge of the atomic nucleus...
00:36:02 ...is correct.
00:36:04 The experimental results confirmed it in terms of quality and quantity.
00:36:13 The difference from the predicted values is within 5%.
00:36:17 The super-heavy elements...
00:36:19 ...proved 10 times more stable than predicted theoretically.
00:36:25 This is one major thing.
00:36:28 These experiments confirmed all the theoretical concepts.
00:36:35 Regarding the practical use of these elements...
00:36:40 I should say that the results of these experiments...
00:36:45 ...conducted here and in CERN...
00:36:48 ...are not of any practical use. These results are too hard to obtain.
00:36:55 You can hardly do it anywhere else.
00:36:59 The practical use arises...
00:37:04 ...from everything we do on the way.
00:37:08 You are forced to review a lot of things.
00:37:12 Sometimes you have to invent an electronic system which doesn't exist.
00:37:16 But you need it for your experiments.
00:37:19 Or you must design a plasma source which doesn't exist.
00:37:23 But you want it. Otherwise you can't do anything.
00:37:26 And there are a lot of things like that.
00:37:30 We must upgrade the chemical equipment...
00:37:33 ...which explores single atoms to define chemical properties of new elements.
00:37:38 We get a lot of spillover effects.
00:37:42 Imagine a drag behind a trawler.
00:37:48 And it brings you so many new fish.
00:37:52 Yes, we can aim for super-heavy elements.
00:37:58 Or they aim for Higgs boson in CERN.
00:38:01 But the research of the Higgs boson brings so many new things in other areas.
00:38:06 This is the practical use of this kind of research.
00:38:11 The point is that many talented people dedicate their lives to this program.
00:38:18 And this is what pushes the science forward.
00:38:21 I believe this is very important.
00:38:27 It's almost like alchemy.
00:38:31 Yes, by the way, this is also very interesting.
00:38:37 Of course, this research of new elements...
00:38:40 ...is sort of ancient alchemists' dream come true.
00:38:46 They wanted to turn lead into gold.
00:38:54 In order to accomplish this goal...
00:38:57 ...they heated lead, hammered it...
00:39:01 ...treated it with extremely corrosive substances.
00:39:06 They got it right that this transformation required energy.
00:39:12 But they could never understand how much energy they needed.
00:39:16 If they hammered lead at the speed of a tenth of the speed of light...
00:39:21 ...they could probably accomplish their goal.
00:39:25 The point is...
00:39:28 ...that if you want to convert an element into another one...
00:39:32 ...you have to convert its atomic nucleus.
00:39:35 It's not about electrons. It's not about chemistry.
00:39:38 You must convert the atomic nucleus.
00:39:41 That would mean a nuclear reaction. Alchemists couldn't do anything like that.
00:39:50 Can you explain me the island of stability?
00:39:54 Could you elaborate on that?
00:39:57 Well, this is...
00:40:00 The new theory put forward the following concept.
00:40:06 The higher the atomic number is or the heavier the element is...
00:40:11 ...the shorter its half-life is going to be.
00:40:17 But this trend will be reversed with very high atomic numbers.
00:40:24 Because the nuclear matter is not amorphous...
00:40:28 ...like liquid, like a drop of water.
00:40:31 It has some inner structure.
00:40:33 And this inner structure is the reason behind the increase of the half-life.
00:40:38 This increase...
00:40:42 This area where the elements will be stable enough was called an island.
00:40:50 Compared to the elements we have got now which are like a continent.
00:40:55 Hence this name.
00:40:58 This is why when we talk about super-heavy elements...
00:41:01 ...and you ask me where they are, I would say that they are on the island.
00:41:06 These are island elements, if I may say so.
00:41:11 Like Britain is an island. These elements are somewhat similar.
00:41:17 Right...
00:41:20 Another important point is that the peak of this island is pretty high.
00:41:26 The elements there may be very stable.
00:41:30 At the moment we deal with the isotopes...
00:41:37 ...which are decay products of these future elements...
00:41:41 ...and their half-life is 30 hours. Or a day.
00:41:44 But this is not the limit.
00:41:46 We should approach the peak of this island. But we can't do that now.
00:41:50 We put a lot of effort...
00:41:53 ...into reaching this island and stepping on it.
00:41:57 But now we must climb the mountain.
00:42:00 One of the goals we want to accomplish at our super-heavy elements facility...
00:42:06 ...is to climb this mountain.
00:42:08 Of course, we are destined to lose a lot on the way.
00:42:11 Probably, we will produce nothing but single atoms again.
00:42:15 But these atoms will be stable for a very long time.
00:42:18 And this is something we must do.
00:42:24 Since the half-life of these elements is so long...
00:42:29 ...can we probably find them in soil...
00:42:32 ...or in cosmic rays?
00:42:35 We still hope to do so.
00:42:38 We keep on conducting experiments...
00:42:43 ...under the Alps.
00:42:47 In the tunnel which joins Italy and France...
00:42:51 ...there is an underground laboratory with the Alps for its roof.
00:42:57 4000 meters high.
00:42:59 The Alps protect this lab from cosmic rays.
00:43:02 We work in a clean environment. And we can record extremely rare events...
00:43:08 ...of super-heavy elements decaying in the natural samples...
00:43:12 ...if they are present there.
00:43:15 The instruments we are using let us record...
00:43:19 ...even one decay event per year.
00:43:23 This is the thing.
00:43:26 Just imagine.
00:43:28 This is less than the concentration of gold or uranium in soil...
00:43:33 ...by about 17 orders of magnitude.
00:43:37 17 orders of magnitude.
00:43:41 Other methods...
00:43:47 ...Professor Flyorov developed...
00:43:50 ...provide for the search for these elements in cosmic rays.
00:43:53 Though not present in the solar system these elements may exist in outer space.
00:43:58 Or maybe these elements...
00:44:02 ...which were formed in the solar system 4.5 billion years ago...
00:44:06 ...are being formed on other planets right now.
00:44:09 And we can trace them in cosmic rays.
00:44:12 By the way, the composition of these rays is similar to those we find on Earth.
00:44:17 But they are younger.
00:44:19 And they may contain traces of these elements. This is another point.
00:44:24 I mean...
00:44:28 ...that we don't know how high the peak of this island is.
00:44:34 We don't know if this is the only island like this.
00:44:37 Or if there is another one made up of even heavier elements.
00:44:42 Those would be hyper-heavy elements.
00:44:46 But we should understand...
00:44:50 ...analyze and interpret or even predict this possibility...
00:44:54 ...through the research of the things we have obtained by now.
00:44:58 This is why we pin hopes...
00:45:05 ...on this super-heavy element production facility.
00:45:08 Factor 100 may help us...
00:45:12 ...answer this question. Or not.
00:45:18 In that case we will have to find some other way.
00:45:22 This is what scientific life is all about.
00:45:26 Are there many factories like this in the world?
00:45:30 None. This is the first one of its kind.
00:45:33 The very first one.
00:45:35 I hope there will be more. But this is the very first one.
00:45:40 This is the first factory?
00:45:43 We'll see how it's going to work.
00:45:45 If this concept proves attractive we'll have more factories like this.
00:45:51 And why is it built here? In Russia?
00:45:56 Why is it built here, in Russia? In Dubna?
00:45:58 But this is our idea and our concept.
00:46:04 We decided to stop and redo everything from scratch.
00:46:11 This is our idea and our design.
00:46:14 We designed the accelerator and the rest of the instruments.
00:46:19 Even the building. We designed it, too.
00:46:25 This factory should be around the corner.
00:46:29 Then I can stand up and go and see what's going on there.
00:46:36 We presented this project to the Scientific Council.
00:46:41 That was 5 years ago.
00:46:50 Even 6 years ago.
00:46:53 Of course, the project required significant financial investments.
00:46:58 It is a large-scale project. In fact, we were talking about a new laboratory.
00:47:03 With a new accelerator and a whole new set-up.
00:47:09 The Council approved the project.
00:47:12 And we received money to go on with it.
00:47:15 The JINR Scientific Council approved these investments...
00:47:22 ...into one of the most promising areas of research.
00:47:27 On the other hand, in the USA...
00:47:34 I went there twice. And we submitted a request to the Department of Energy.
00:47:40 And they approved our project, too.
00:47:44 The general feeling is...
00:47:48 ...that it is a promising program and we should carry on.
00:47:51 The factory will be another step forward in this direction.
00:47:59 That's a magical thing that you created. This factory.
00:48:06 No, this is...
00:48:09 I think this concept made sense.
00:48:12 It is based on everything we already did.
00:48:16 At some point we had to stop...
00:48:20 ...and choose our way. This is what we do in life.
00:48:27 But you are standing on the shoulders of people like Flyorov.
00:48:33 Well, yes.
00:48:37 I am really sorry Flyorov didn't live long enough to see it.
00:48:44 Neither Flyorov nor Seaborg in the US.
00:48:48 They desperately wanted to produce super-heavy elements.
00:48:52 And they did a lot...
00:48:55 They did a lot to make their dream come true.
00:48:59 But unfortunately, we found the right way to do it when they passed away.
00:49:07 Could you explain me about the elements?
00:49:11 How do you make an element?
00:49:17 If we want to transform an atomic nucleus I was talking about earlier...
00:49:22 And we have to do it to convert an element into another one.
00:49:28 Then we should manipulate it in some way.
00:49:35 One of the most obvious methods is...
00:49:39 ...for example to fuse two atomic nuclei.
00:49:44 We should bring them into contact.
00:49:48 And then...
00:49:52 ...the forces of nuclear attraction will...
00:49:54 ...make the bigger nucleus take up the smaller one.
00:49:58 This process is called fusion.
00:50:03 But first we have to bring them into contact.
00:50:06 Both nuclei are positively charged.
00:50:09 And we should find a way to overcome the repulsive force between them.
00:50:13 This is why we must accelerate the nuclei.
00:50:17 Their velocity should be high.
00:50:19 About one tenth of the speed of light.
00:50:23 And so, we need some machine to accelerate the nuclei.
00:50:26 This machine is called an accelerator.
00:50:32 Let's assume I would like to produce...
00:50:39 ...element with the atomic number 100. I would take uranium I can find in soil.
00:50:44 Its atomic number is 92. I will use it to make a target.
00:50:48 The target will contain atoms of uranium.
00:50:51 I would blast it with nuclei of oxygen.
00:50:53 But I will have to accelerate the nuclei of oxygen...
00:50:56 ...to the velocity of one tenth of the speed of light.
00:51:00 I can't accelerate oxygen as is. Because it is neutral.
00:51:04 I want its nuclei to be charged.
00:51:06 Then I can use an electric field to propel them.
00:51:10 This is the reason I have to inject the oxygen into plasma...
00:51:15 ...which will strip electrons from the nuclei.
00:51:18 Without an electron a nucleus will have a charge of +1.
00:51:21 Without two electrons it will have a charge of +2 etc.
00:51:28 The hotter the plasma is the more electrons I can pull away.
00:51:32 This is what I call an ion source.
00:51:36 It helps us convert a neutrally charged atom into an ion with a positive charge.
00:51:41 Then I am taking this ion out...
00:51:45 ...and I am putting it into an acceleration chamber.
00:51:51 The ions accelerate in an electric field.
00:51:56 You have to apply an electric field to propel them.
00:52:00 There are two ways to do that.
00:52:03 You can build a very long accelerator...
00:52:08 ...with the electrodes placed along the pipe.
00:52:11 Slow particles will be propelled to one tenth of the speed of light at its end.
00:52:16 Or you can make the particles travel in a circular path.
00:52:21 But you need a magnetic field to do that.
00:52:24 You need a large magnet like those you can see in the accelerators.
00:52:28 They hold the ions to their trajectory.
00:52:31 This magnet is about 4 meters in diameter.
00:52:34 It generates a magnetic field.
00:52:40 It makes the ions travel in a circular path.
00:52:43 There are also two electrodes which generate an electric field in the chamber.
00:52:48 The electric field accelerates the ions.
00:52:52 But you need to synchronize the process.
00:52:55 You need to accelerate the ion here...
00:52:57 ...and accelerate it again half way through the circle.
00:53:01 This is the reason we want alternating voltage.
00:53:04 It is alternate and not constant.
00:53:08 The voltage cycles should be in sync with the movement of the ions.
00:53:13 Accumulating energy of the ion will make it move outwards.
00:53:19 Its trajectory will look like a spiral path outwards from the center.
00:53:24 And when the ion reaches the rim...
00:53:26 ...two meters away from the center it will accumulate the maximum energy.
00:53:32 Then we should take the ion out of the chamber and send it to the target.
00:53:37 It is the operating principle of an accelerator.
00:53:40 It is called an orbit accelerator or a cyclotron.
00:53:44 The particles travel in a circular path. Their trajectory is spiral.
00:53:48 This spiral path is several kilometers long.
00:53:54 An ion completes about a hundred circles.
00:53:59 And this is enough to propel it to a one tenth of the speed of light.
00:54:04 Then this ion can come to the atomic nucleus of uranium close enough.
00:54:10 They can fuse.
00:54:13 As a result of this fusion we can add up...
00:54:17 ...Element 92 and Element 8 to produce Element 100.
00:54:22 Of course, there's a chance that they won't fuse. Or some may fuse partially.
00:54:28 But these will be side effects and products we are not interested in.
00:54:35 And we should get rid of those...
00:54:37 ...to see what we want to see. And we want to see Element 100.
00:54:42 When we talk about super-heavy elements...
00:54:47 ...we should get rid of a trillion of side products.
00:54:52 A single atom and a trillion of side products.
00:54:55 This is the reason these experiments are so complicated.
00:54:59 We must ensure ultimate selectivity.
00:55:04 And so...
00:55:07 ...this process...
00:55:11 ...of accelerating, bombardment, and fusion...
00:55:15 ...is the principle behind the production of super-heavy elements.
00:55:19 There is another issue with super-heavy elements.
00:55:22 I gave you an example of uranium.
00:55:26 We can find uranium in soil.
00:55:28 But we want artificial elements to produce super-heavy ones.
00:55:31 And they don't exist in nature.
00:55:34 Plutonium, curium.
00:55:36 You need a very powerful reactor to synthesize those.
00:55:40 And so, you utilize both reactors and accelerators.
00:55:44 You want a reactor to produce a target.
00:55:49 You breed material for your target there.
00:55:53 Then you place the target into your machine.
00:55:56 Then you accelerate the ions to produce new elements.
00:56:02 This is what makes these experiments so complicated.
00:56:05 They get even more complicated when the half-life of the target is short.
00:56:12 On the one hand, you want more neutrons in your target.
00:56:17 On the other hand, the more neutrons you have the shorter its half-life is.
00:56:22 We set a record.
00:56:25 I mean the element with the atomic number 117.
00:56:29 The target was made of berkelium.
00:56:31 The half-life of this isotope is 300 days long.
00:56:37 This is why when we prepared this experiment...
00:56:41 ...first, we had to breed enough material.
00:56:45 And the reactor should have been powerful enough.
00:56:49 Then we had to separate the material chemically.
00:56:54 Then we had to bring the isotope from one hemisphere to the other one.
00:56:59 Then we had to install the target...
00:57:01 ...and bombard it for another 300 days.
00:57:08 When we got our first results, many American colleagues said...
00:57:12 ...that it was a tour de force.
00:57:18 Other isotopes had longer half-life. Working with them was easier.
00:57:25 This is more or less what it looks like.
00:57:29 Ok. I understand. Could you also explain to me in simple terms...
00:57:33 ...what is the classical theory?
00:57:36 This is a very good question.
00:57:45 The history of nuclear physics...
00:57:50 ...dates back...
00:57:53 ...to March 7, 1911.
00:57:57 That day Ernest Rutherford attended...
00:58:03 ...a meeting of the Manchester Philosophical Society and said:
00:58:07 'I believe this is what an atom looks like.'
00:58:10 'There is a small and dense nucleus in its center.'
00:58:15 'It is positively charged.'
00:58:18 'And the electrons orbit it at some distance.'
00:58:21 'And they are negatively charged.'
00:58:24 Nobody could understand the structure of the atom before.
00:58:29 There are electrons which are charged negatively.
00:58:32 But an atom is neutral. That means there is something positively charged inside.
00:58:36 But how can positive and negative charges co-exist?
00:58:41 The opposites should attract and annihilate.
00:58:47 Rutherford likened the atomic structure to the solar system.
00:58:52 Planets orbit the Sun. But it's all about gravity in space.
00:58:56 And here we deal with electromagnetic interaction.
00:59:00 The dense nucleus is charged positively.
00:59:03 And the electrons orbit it.
00:59:10 His concept was not immediately understood or accepted.
00:59:18 But as the physicists including Rutherford himself looked into the issue...
00:59:23 ...they discovered proofs of this concept which was called a planetary model.
00:59:35 In fact, the nucleus is small, round, and dense.
00:59:42 The nucleus is incondensable.
00:59:45 You can't condense it.
00:59:48 Ions bounce off it but can't condense it.
00:59:53 And then, back in 1928...
00:59:56 ...our compatriot...
01:00:00 ...who later became a famous American scientist, George Gamow...
01:00:07 ...said that a nucleus is similar to a drop of liquid.
01:00:16 To a drop of water. Though a tiny one.
01:00:20 But it's denser than water by 15 orders of magnitude.
01:00:26 And he suggested a liquid drop nuclear model.
01:00:30 In fact, a nucleus has got a distinct shape. It is spherical.
01:00:38 It is incondensable.
01:00:43 I would call this a rather bold metaphor.
01:00:49 Because a liquid drop is a macro object.
01:00:53 And a nucleus is a micro object.
01:00:57 Macro objects are subject to Newton mechanical laws.
01:01:01 Micro objects are subject to Einstein laws.
01:01:05 And we compare a nucleus to a macro object.
01:01:13 But that model proved extremely efficient.
01:01:20 It helped us predict the discovery of atomic binding energy.
01:01:24 It likened particles to molecules of water.
01:01:27 It helped us predict the fission phenomenon.
01:01:36 It helped us predict some decay events.
01:01:41 In this way it is a classical one.
01:01:44 We apply a classical metaphor of a liquid drop to a nucleus.
01:01:49 But...
01:01:51 ...a liquid drop is amorphous.
01:01:54 It has got no inner structure.
01:01:58 And later we found out that a nucleus has got an inner structure.
01:02:02 This inner structure is the only reason we can produce super-heavy elements.
01:02:07 Without it we could never produce any of them.
01:02:12 Because the classical theory likens a nucleus to a liquid drop...
01:02:17 ...and gives us an exact limit. There can be no elements heavier than 100.
01:02:23 All the heavier ones were produced because the nucleus has a structure.
01:02:28 The matter has got its inner structure.
01:02:33 I am going to try and help you visualize this structure. Imagine a liquid drop.
01:02:38 And now imagine a snowflake inside this liquid drop.
01:02:43 The snowflake is sort of a carcass.
01:02:48 It may be tiny but it is still a carcass.
01:02:52 And when you approach the limit of nuclear stability...
01:02:56 ...when the repulsive forces of positively charged protons...
01:03:01 ...equal the attraction forces...
01:03:04 ...this tiny carcass makes a very heavy nucleus stable.
01:03:11 This is the fundamental base of the island of stability of super-heavy nuclei.
01:03:18 This is what the classical theory is about.
01:03:21 The later theory which considers the atomic structure...
01:03:24 ...was called a microscopic theory or a quantum theory.
01:03:50 This is something we can call the body of evidence of the nuclear physics.
01:03:57 For the last 3.000 years. Everything we know today.
01:04:02 Some experts say that we can go back to 6000 years.
01:04:06 Just imagine the potential.
01:04:10 The black squares here are...
01:04:14 ...the nuclei of the elements which occur naturally in soil.
01:04:18 They were formed with the Earth itself...
01:04:21 ...4.5 billion years ago.
01:04:26 You can follow these black squares up to lead and bismuth.
01:04:33 There are no black squares after those.
01:04:35 You can see a narrow neck...
01:04:37 ...and an area we call a peninsula.
01:04:44 You can see some black squares in the middle of it.
01:04:49 These are thorium and uranium.
01:04:51 They came into existence together with planet Earth, too.
01:04:56 But they decay right before our eyes.
01:05:02 Both thorium and uranium are radioactive elements.
01:05:05 And this is the end of it. No more black squares.
01:05:08 The colors turn light.
01:05:14 It's almost white now.
01:05:15 That means that the half-life of these elements is very short.
01:05:19 You can see 22 grades of their half-life.
01:05:26 From black to blue.
01:05:29 The blue color stands for the atoms...
01:05:31 ...with the half-life of less than one microsecond.
01:05:35 The black color stands for stability. Lead is the last black square.
01:05:39 It is followed by the peninsula with uranium and bismuth on it.
01:05:43 Then we see transuranium elements which are produced in the reactors.
01:05:49 These are the elements bred in the US reactors...
01:05:52 ...which we bring here to make targets and produce super-heavy elements.
01:05:56 And if you look even higher you can see a small sand bank...
01:06:03 ...and a big island. This is the island of stability.
01:06:07 The island of stability of super-heavy elements.
01:06:10 This island is a concept which haunted scientists for many years.
01:06:15 Does it exist or not?
01:06:18 Yes, it does exist.
01:06:21 We stepped on this island and we produced six elements...
01:06:27 ...and 16 different nuclei or isotopes of these elements.
01:06:31 We probed this island in many places.
01:06:34 And we proved that it is in fact an island of stability.
01:06:40 This is what it's all about.
TV Get inspired and watch tv episodes of The Mind of the Universe, made by Dutch public broadcaster VPRO
  • Browse through over 30 hours of interviews
  • Download the interviews, including subtitles
  • Remix, re-use and edit under CC-BY-SA license
  • Start exploring