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Helmut Dosch

Helmut Dosch

Chair of the Board of Directors, Deutsches Elektronen-Synchrotron (DESY), Helmholtz Association, Hamburg

Taking x-rays beyond the limitations of the mid-80s, Helmut Dosch has developed an ‘optical trick’ that gives us an insight into the molecular structure of surfaces and interfaces. Dosch gained prominence through his research on synchrotron radiation contributing to the use x-ray scattering as a method in surface science, order-disorder phenomena in condensed matter, fluctuations in matter and nano-oxidation. With these successes in place, Dosch’s work promises to make a landmark contribution to the scientific panorama by rendering the premelting of ice well below zero degrees centigrade. Currently the Chairman of the DESY Board of Directors and an advisor to several renowned institutions including the Mienerva Weizmann Committee and the Europhysics Letters, Dosch’s most recent breakthrough promises to be of utmost importance in an age of environmental degradation as it implies the existence of water under extreme conditions.

Breaking the Wall of Quantum Cinema. How High Speed X-Ray Lasers will Allow Us to Make Life Reports from Molecules at Work and from Chemical Reactions

Transcription

When the wall came down, I was in Munich in a bar. It was an unbelievable atmosphere; we all had the feeling that we were witnessing a great event.



Thank you very much. So, I have now the first wall to break between my lecture and the previous one. What I would like to invite you to is, again, a travel into the Nanoworld, so you have to be a little bit concentrated here. At the end of my talk I will present to you, so to speak, a high-speed camera, which should allow us in the next decade to make movies like this. These are two water molecules during springtime. We would like to see how bonds break and how they are formed. Why we are interested in that, and what this would be the benefit for that. This is the topic of this short presentation. We talk about movies, cinemas, so the whole talk is made as a movie, and it starts the same way.

Lets go into the Nanoworld. There was one wall, which was broken almost now one hundred years ago- more than hundred years ago- by Roentgen, who discovered the X-rays, which actually were the tools at hand to really get into the Nanospace. With this one, you could do this break through experiment, which is actually almost one hundred years old now; namely this famous experiment by von Laue, who took an X-ray tube and put a crystal in it. We heard about that a couple of seconds ago. What he found for the first time, this is a photographic film, and he saw this in the interference (? 25:12). This was the first signal ever for mankind that atoms exist. They came from this crystalline structure, and it opened, so to speak, this interference pattern, our eyes for a new length scale, namely the Nanometer length scale, which is the distance typically between atoms in every structure you see around you. With this Nanometer: we have been living in the millimetre range, and all of the sudden you have to go to the Nanometer range; this is this incredible small number.

To visual that, for those of you who are not working everyday in these times, in this length scale, the earth is 13,000 km long. This is a forbidden currency, as you know, so there is the penny 13mm across. If the earth would shrink to a metre, now the penny would shrink to a Nanometer. This is, roughly speaking, the challenge one has in order to go this length scale. This happened one hundred years ago, I said, and so the Quantum theory was developed, X-rays were developed. So, you see again, this interference pattern.

If you reflect what was at that time, the most impressive technological achievement. Some people think it was the Eiffel Tower at that time. It was build out of many, many bolds; it was 300 metres high. This was the architecture of that time. After this discovery, we live today. Our world has changed completely. Now we are dominated by discoveries, which are made in the Nanoworld, (? 26:58 so formatical) to information technology. This is the Pentium processor, which has 30 million transistors on the square centimetre. This is what we have today, and this all goes back to the discovery, which has been done one hundred years ago.

To illustrate that again, you see here scenery in the southern part of Europe during lunchtime. You see that these people are enjoying themselves. They would not be able to do that if not many, many smart materials are working every Nanosecond to make their life pleasant, health, mobile, communicative.

You see that here, these are the materials, which are doing work everyday- every second for you. You can see from this discovery of the Nanometer range, we really profited all enormously from it, right? This world and this technology would not be possible without these discoveries.

The question is: we would like to improve everything, right? We would like to have better medication, vaccine for diseases; we would have better materials for transport and energy, we need better communication technology. Question is: how can we make now a step forward? We are facing a limit. This is the topic of this talk.

So, the question is, Which is the Next Wall to Fall here?

I illustrate this to you with a comparison. Reflect back in the early months of this year, we had the World Championship 2010. Imagine we are watching this game now; the game is on, the two teams are here on now, and we would like to see the game. Now imagine the following happens. You see this.

The next on the screen you see this. It is a wonderful result, right? It is wonderful, so we love it! But, we missed something very, very important: we didn’t see the game. We didn’t see the match. It is fine with us: the result is fine. But, we don’t understand what is going on. We don’t know how the whole thing evolved. We even don’t understand the name of the game. It is terrible, right?  But this is the way in which we understand Nanoscience at the moment.

I give you an illustration. A very simple chemical reaction: this is Germany and this is Argentina, right? This is the result (Laughing in audience). This is roughly speaking. So you put them together, and here is the result. What is happening in the chemical reactions, as we can do it today is this- right here- wham- and we create H2O. This is all we see. What we are missing is, of course: how does this reaction evolve in real time? We want to see how they bond together, what is going on in detail; and if we can see that, can we identify, so to speak, transient states in between? Are they trapped in the immediate states, and so on and so forth?

In other words, we would like to see this, right- in the real space? (Laughing in audience) We want to see game. Here is a famous one: Germany-England. You see here is a transient state. (Laughter and clapping) You can see fairly clearly it is no goal, right? (Laughing in audience) That is also a contribution to the first talk, which was dealing with Schadenfreude, do you remember that? (Laughing in audience) So, you see in order to understand such a dynamical process, you really have to understand this with the necessary spatial and temporal resolution. For the soccer, it was milliseconds, and centimetres, if you have that. This is what you need: fifty milliseconds should be sufficient; usually, the referees don’t have that. They make these interesting decisions.

So, in the Nanoworld it would be this. We would like to see in real time how- this is a little Nanodot- is oxidising in real time. That is a very costly computer simulation. It shows the oxygen molecules approaching the surface, and then oxidising here the Nanodot. You see here the time evolving- PS: it is not energy; it is picoseconds. This is how it developed. You see here is the soccer time scale: 50 milliseconds, and now if you want to go to this time scale, you have to move to the micro-, to the nano-, and then it goes to the picosecond: it is not even sufficient; you have to go to this unbelievable time scale, which is femtoseconds. That is the Nanoworld. That means if you want to follow that in realtime, you have to first of all have the necessary spatial resolution to see this. You have to see the atoms, and you have to be so fast that you are faster than the atoms move. So, you have to make a camera, which is as fast as femtoseconds.

What does femtoseconds mean? Comparison: velocity of light, breathtaking velocity of 300,000 km/sec.; this is the distance to the moon. If you switch on a candle here at 1.3 seconds, now it is on the moon, right?

Another experiment: maybe you know this person in Berlin (Nina Hagen)?  If you take her hair, and this is typically 50 micrometre, and you should light through it- It was too fast for you, right?

Then you see this is the difference if you make a subtraction of it; then you find out that it is 200 femtoseconds. It means that we have to be so fast that light in the time when we are observing is only travelling across the thickness of a hair. That is the challenge of it.

That means this is what we need, right? The Dream of Mankind. We would like to make realtime holograms of the motion of atoms, molecules, and electrons, in order to understand matter better. This is a droplet moving, so we have to have two walls, in fact, to break. We have to create the laser, because we want to make holograms in the X-ray range, which has not been done before. We have to take pictures faster than atoms move- femtoseconds.

The question is: can we do that? The answer is...(Laughter in audience) This is the camera, which is currently being built in the Hamburg area. So, it is a strange camera. Here is DESY, where we are working. We are constructing a relativistic electron gun. Here is Schleswig Holstein, right? We are shooting from Hamburg to Schleswig Holstein with a super conducting accelerator, and these electron bunches now are hitting here, particular magnetic structures, which convert these electron bunches in X-ray flashlights. Here we have done the experimental stations where we can make the movies. That is the way in which it goes. This is an enormous enterprise. So you see, again, from the DESY side, here is the injector building; and you see here on top, this is then the accelerator, which is built underground: it is working at -221° C. So, we accelerate up to 7 billion electron volts. Here is the Electron- the magnetic structure- this is the flash. If this flash is produced, then we can make exposures of the molecules, and then we create the molecular movie. That is the way in which it goes.

This is a big microscope that we are building; so it is a multinational, European exercise. Many, many nations are joining us here together to build this in this very second. This is the benefit of that. We would like to see the Nanoworld in realtime; for example, we would like to have better computers of the future. Our future computer should not switch off- as we switch the computer- but keep the memories; so we would like to have Nonvolatile Memories. So, the name of the game is to find out how a magnetic Nanodot switches in time as fast as we need it, because you have to address that. This is completely unknown. A lot of experiments are going on, so you have to switch it with this frequency if you want to address that with the CPU Frequency of your computer. This is an important technology of the future.

Even more important for energy is that we have to control catalytic reactions better. So this is our catalyser. Here is the CO, NO, which comes from your motor. Here you see comes the CO, the monoxides in, here you have the oxygen; the oxygen gets disassociated at the surface, and then the oxygen atoms are then oxidising the CO. In order to understand this catalysing reaction really, you have to see it in realtime how these motions are, because the CO reaction depends sensitively upon the surface reaction- all the other atoms here. That means even catalytic industries, who are building catalysers, tell us now that they would like to see that in realtime. That is the challenge that we have.

Also for better medication: such a time resolution is, of course, the way to go. We would like to understand now in infection biology: how are the first molecular reactions when you get an infection? That one can actually create better medication if one understands that in a better way.

That is all I wanted to tell you. You see this Quantum Cinema is not only a nice toy, but it is also an advanced technology that we can really develop better drugs, more efficient energy, and that we get more better material for our knowledge and society of tomorrow. Thank you very much.

 

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