Karsten Buesser

Summer in Hamburg

Finally, Summer has come to Hamburg! And contrary to common beliefs, the sun does shine here (at least from time to time). So here are some proofs:

 

This is one of my favourite spots, the big lawn in Jensichpark. This place is just a 10 min ride on a bike away from DESY. You have this really nice view down to the River Elbe. Most people think (assuming they ever heard about Hamburg) that Hamburg is very close to the sea. But that is not true. The North Sea is about 120km downstream the river from here. But Hamburg has a big port (the second biggest in Europe) anyhow. That means that the Elbe is really an interesting river with a lot of big ocean-going ships passing by:

Here is one of them. Actually a quite small one. The buildings on the other side of the stream belong to the Airbus plant in Hamburg. A lot of parts for all of the Airbus planes are build here. And some of the smaller types are assembled in Hamburg. Have you ever been in a A321, A319 or A318? They were born on the banks of the River Elbe. Even the A380 (the new big one) has its roots here. Some parts of the fuselage are being built here, the whole interior and the outer paintings will be done in the newer buildings on the right.

This is the pier of Teufelsbrueck. Boats are a common measure of transport in Hamburg. You can use them like a bus, the bus tickets are even valid on them. In the distance you can see the outer parts of the Hamburg Container Port. Here is a close-up:

So all in all the river banks are a very nice and interesting place for a stroll. And the best of it is that DESY is so close by so that is absolutely no problem to spend the lunch break here.

Vacation

Finally a trip for fun and not for business! Sorry for being quiet the last weeks, but finally I was able to take a week off and go on vacation. Being on a trip with the family is naturally quite different from going to a conference; and it is much more fun. So last week we packed the car (and believe me, you gotta pack a lot when you travel with a one-year old kid!) and went off to Denmark.

Why Denmark? Well first of all it is close. The border is just a 1.5h drive from Hamburg. And then of course Denmark has a fantastic coast to the North Sea, endless natural beaches with broad dune areas. So a perfect place for a kid starting to have fun in the sand following  the saying that the three basic rights for children are swings, sand and water.

So we rented a brand new house in the dunes (see picture below) and enjoyed a week with fantastic weather having long walks on the beach (remember that this is Northern Europe, spring is still a cool season here).

Here is a view of the house we rented (the black one on the left).

Another view. The path leads directly to the beach, just 200m through the dunes.

I just recognize now that I made no photos on the beach. It always had the video camera with me, but not the stills camera...

This was really a relaxing week, now I try to cope with my overfull INBOX and the mail on my desk.

Rainy California

Last week the biggest event for the ILC physics and detector community, the International Linear Collider Workshop LCWS2005, was held at Stanford University in California. When I registered for that workshop a couple of months ago, I really anticipated a nice sunny week in the californian spring. Well, unfortunately the rain season was extended this year, so it was one of the wettest weeks I can remember (and let me remind you that I live in Hamburg!). But nevertheless it was a very exciting and interesting conference. And by and then the weather allowed even for some nicer photos.

Here you can see me at the very beginning of the journey, still at Hamburg airport:

This was the conference venue: the William R. Hewlett Teaching Center at the Campus of Stanford University:

Stanford really has a nice campus. I wonder how it would have been if we really had california-style weather:

The main social event of the conference was the dinner cruise on the San Francisco Bay. The weather gods showed mercy and presented us the only few rainless hours during that week:

And here is a nice picture of the Golden Gate Bridge, almost in the sun... but watch out for the new rainclouds coming in.

Despite (or because of?) the weather the workshop really was a success. Some 400 colleagues were meeting to discuss the physics potential of the ILC and the challenges the physics imposes on the detectors needed on this facility. It is very encouraging to see how the community grows and starts to organise itself.

Spring Meeting in Berlin

This is a live report from the spring meeting of the German Physical Society (DPG) in Berlin. Every year the DPG organises a series of spring meetings for the German physicists. Normally it is a series of 5-6 topical meetings, well separated in the major branches of physics. So usually we particle physicists meet in a nice German town and discuss what has happened in our field during the last year.

But don't forget, this is the World Year of Physics! So this year all the topical meetings have been combined in one big conference. About 7000 physicists are here. And they come from all branches of our field: Astrophysics, Condensed Matter Physics, Quantum Optics, Quantumgravitation, Nuclear Physics, and so on. I just heard on the news that this is the largest physics conference ever held in Europe, and I believe it. Berlin is really crowded with physicists. I wouldn't believe that 7000 physicists are noticeable in a 4Mio citizen city, but they are! You recognize them everywhere.... How? Well, I really don't know exactly, but whenever I am sitting in the U-Bahn here and I see groups of mostly males standing around, all equipped with laptop backbacks and all in casual clothes, I am pretty sure I know their profession.

A large group of colleagues from DESY is here with me. It reminds me a little bit of the school trips I participated some 20 years ago. Here is a picture of a bunch of DESY physicists entering the train from Hamburg to Berlin:

 

But know of course the purpose is not primarily to have fun, but to do real and important science. So here you can see some of them doing important physics also during the coffee breaks:

      

So it is just the second day today, four more are to follow. It is now already a really impressive event, I heard a lot of very interesting talks. Tomorrow even the Chancellor of Germany, Gerhard Schroeder, is expected to give a speech here. I am really looking forward to that. It is always interesting to hear politicians speaking about the future of our profession. At the end they are the people who pay us, right?

So stay tuned, I'll keep you updated....

The cold ILC

Finally snow! Snow is not a really frequent thing in Hamburg. We have a very maritime climate here, so winters are usually gray and rainy. But this morning when I got up and looked out of the window, everything was white. Beautiful. So and here you see the real cold ILC.

As you might know, the technology for the International Linear Collider is based on superconducting accelerating cavities. Superconductivitiy is a nice feature of nature which appears in certain materials, like the metal Niob out of which the accelerating structures, the heart of the ILC, are made. If Niob is cooled down to real deep temperatures, like -270 degrees Centigrade (what's that in Fahrenheit?), its electrical resistance vanishes. This allows the almost loss-less storage of electromagnetic energy in the Niob structures which helps a lot in accelerating the particles. To get down to such cold temperatures of course snow is not sufficient for cooling. To get down to -270 degrees one has to use liquid Helium.

Ok, that's the physics lesson for today. Unfortunately the snow already melts away outside. So I guess we are back to the gray and rainy defaults.

Communication with communicators...

I had a really relaxing last weekend until on Saturday evening my phone rang and I found myself talking to the husband of Petra Folkerts, the head of the PR office at DESY. Unfortunately Petra got ill and completely lost her voice (that’s why she asked her husband to phone me). Petra was supposed to go to the meeting of the ILC Communicators which took place at CERN on Tuesday and Wednesday. And now she asked whether I could go on her behalf. I was a little bit reluctant because my schedule for this week was quite full. But well, I guess you already know that I really devote myself to the ILC, so I managed to get rid of most of my appointments for the Tuesday and decided to go to CERN for just one day.

So on Tuesday morning I boarded a plane to Frankfurt where I caught a connection flight to Geneva (Hello Lufthansa! Could you PLEASE re-install the direct flights from Hamburg to Geneva? It would really improve research in Europe!!!). So I finally showed up at CERN at around 11:00 to join the ILC Communicators. The Communicators are a group of people devoted to foster and improve communication inside and outside the ILC project. So I was sitting around the table with the heads of the PR offices of Fermilab, SLAC, CERN and some other colleagues especially interested in communication issues. We had a very successful and active meeting, discussing a huge agenda of things related to what has to be done next in the PR and communication business. Central point of our discussions was the implementation of the Global ILC Communication Plan. So we debated vividly about the design of web pages and newsletters, how to get communication on the agenda of the next important conferences, and of course the most pressing topic (at least for the view of most of my colleagues): the design of a common ILC logo.

So we had quite a few examples of logos on the table and liked none of them. The comments were in the range from:'This looks like a logo of a big international logistic company' (which is probably not a too bad description of what the ILC is right now…), to 'Oh, this looks like a set of colliding sex toys'. This comment, by the way, was made by a very distinguished British professor… So the conclusion of this session was, that we should go back to the drawing boards. But we have a quite good idea now about how to proceed.

So after a full day of intense working I flew home, this time via Munich (again, please Lufthansa, do it!) and 17.5 hours after I left my home that morning I was back home.

Inflation of Meetings

Ok, last week I hope I made a clear point in why it is interesting to devote your life to the ILC. A lot of people have the same view as me, so we are a quite large and growing international community trying to get together the design of this future machine. This is a wonderful fact and we really enjoy the pioneering spirit. And in our pioneering effort we create a lot of meetings to discuss our work. And as this is a truly international effort, of course these meetings are scattered all around the world. If I wanted to attend all of those (and they really deserve it), then I better spend the rest of this year on planes.

Fortunately physicsists have the gift of self-organsiation. It tends to start chaotic, but it comes to order eventually. So finally people recognised that there must be a life outside an aeroplane. And this was a wonderful example where big important lab directors (worried about the travel budgets) and younger researchers (worried about their families) had the same intentions (though different motivations) to limit the inflation of meetings.

An interesting idea under discussion right now is, to define 3 to 4 meeting slots for the ILC community per year rotating around the bigger labs on the world. So whoever wants to organise a meeting knows where and when the next slot is available. The host institute then just offers meeting rooms (and of course coffee!!) and nothing more. The organisation of the meetings and workshops taking place stays in the hands of the people interested in that meeting. And as the meetings then bunch up at one place, there is an excellent chance to have synergy effects between the different groups meeting at that place.

Other interesting concepts of avoiding travel are of course are of course to replace real meeting with virtual meetings, like phone or video conferences. These kinds of meetings could be very effective, but they reach their limits sometimes. Try to organise a phone meeting with Europeans (GMT+0/1), Westcoast-Americans (GMT-8) and Japanese (GMT+8) and you know what I mean….

What is the ILC?

I am spending all of my working (and a considerable part of my private) time to the ILC. So I guess it is worth to have a closer look at that:

The International Linear Collider (ILC) is the next big project of the worldwide community of particle physicists. It is expected to complement the picture which we hopefully get from the Large Hadron Collider (LHC) which is under construction right now at CERN. We know pretty much about nature on its smallest scales. We know that matter consists of quarks and leptons, we know about the four fundamental forces in nature, but there are a lot of open questions still waiting to be answered. Questions like, where are the masses of the elementary particles coming from, or the fact that our Standard Model of the world just describes 4% of our universe. That is the part of the well known matter which forms stars and planets.

We know that 23% of our universe consists of dark matter (our colleagues from astrophysics told us). This is a matter form which underlies the force gravity but it is not visible in telescopes. The best guess that we have on it, is that yet unobserved elementary particles could form that dark matter. Those particles could have been produced in the Big Bang and since then populate our universe without communicating with our known world. There exists a very promising theory, called Supersymmetry (SUSY) which forms a natural extension of our current theory of the world. SUSY predicts a number of new particles which could be the origin of dark matter.

To get a hand on these guys is difficult. The best way to do that is probably to try to simulate the Big Bang in the lab. Particle physicists do that all the time at their particle accelerators in the big labs around the world like DESY. We accelerate elementary particles like electrons to high energies and let them collide. Though the total energy in these collisions is quite small, we produce a very high energy density. This density is about as high as the energy density of the universe a few billionth of a second after the Big Bang. And if we are lucky, the energy density is large enough to produce those SUSY particles which we hold responsible for the dark matter.

The LHC at CERN will be the next machine on the energy frontier. If these particles exist, there is a very good chance that we will find them in the collisions produced there. Really understanding the properties of these particles is hard, though. The key to it are precision measurements. And for those we need precision machines. LHC is an accelerator in which hadrons collide. These are heavy particles which consist of quarks. The reactions which we expect at the LHC are therefore not easy to interpret. We know already now that we need a precision tool to complement the measurements which will come out of the LHC. And this tool is the ILC.

At the ILC we plan to accelerate elementary particles, electrons and positrons, in linear accelerators with a total length of 30-40 km (sorry my North-.American colleagues, I am living in the metric system). The plans for this machine are developing, we hope to have the Technical Design Report ready by the year of 2007. This machine we are planning is probably the most complex machine of the world, or as one of my British colleagues says: ‘This is going to be the mother of all accelerators’.

So why do I devote most of my life to it? This is a question easy to answer. The physics benefits which we are expecting from that machine are unprecedented. We are planning the tool which will produce the science for the textbooks of the coming generations. That is worth some efforts, don’t you agree? And maybe it will help some day to shed some light on the 73% of the universe, the so-called dark energy, still missing in the sum. We don’t know much about it, we just know that this dark energy reacts like an unknown force which accelerates the expansion of the universe.

Kick-Start

So finally I am at my own desk for longer than a couple of hours which gives me a chance to really start blogging.

The new working year really kick-started me into high gears immediately. I spent already the third working day on the plane, going to SLAC near San Francisco for a workshop on the ‘Machine-Detector Interface (MDI)’ of the International Linear Collider (ILC). The definition of what exactly the ‘Machine-Detector Interface’ is is really not easy and is actually still under discussion in the respective working group. Basically it deals with everything where the design of the accelerator has a potential impact on the design of the big detectors planned to record the physics reactions at the collision points of the ILC.

Well, travelling so close to the holiday season usually is a hassle: Long queues everywhere, full flights, delays, etc. I really prepared for the worst but things evolved quite nicely when British Airways upgraded me to their very nice business class on the outbound flight. Why British Airways? Well there are no direct transatlantic flights leaving from Hamburg. So whenever we have to travel outside Europe we have to go through one of the big hubs: Frankfurt, Paris, Amsterdam, London, etc. And the DESY travel policy is to choose the cheapest flights available, so I know all of these airports quite well. Usually I don’t like Heathrow too much, because it is located on an island. A few years ago this really was a problem when I was dumped in Heathrow in the biggest storm hitting the British islands since a long time. It is really hard to escape from an island when neither planes nor ferries nor trains are running….

Well this time British Airways was the right choice, everything went nice and smoothly.

The stay at SLAC was a little bit disappointing though. The workshop was interesting, the organisation was excellent, but the weather…. I mean I knew they had like monsoon season in January, but it really rained cats and dogs for the biggest part of the four days I stayed there.

Coming back a week ago I just spent two nights at home before I went to the next workshop at the Ecole Polytechnique in Palaiseau near Paris. This time it was a meeting of the physics community interested in designing a detector for the ILC based on gaseous tracking with a big time projection chamber as the heart piece. Being an expert for MDI is big fun, but it also doubles the travel. You have to be at the conferences of both parties, the machine and the detector people.

Paris is always nice. I stayed in a nice old hotel near the Pantheon. This is in the 5eme arrondisement of Paris, which is the part where most of the universities (including the famous Sorbonne) are. So there are many nice restaurants, bars and shops in this area. Not that I had much time to spend there as we had to take the 08:00 am train every morning going the 40 min ride to Palaiseau. And to get from the train station to the Ecole Polytechnique you have to climb a hill on a footpath with a very steep slope. You really curse every glas of red wine you had in the evening then….

Well now I am back at home trying to get a grip on my overflowing mailbox and task list. Of course the backside of travelling is (at least here at DESY) that you are the natural candidate to give a report about the workshops you have been at at the next regular meetings here. So now I have to prepare a summary of the MDI and the detector workshop for our weekly ILC project meeting on Friday as well as for our internal group meeting on Monday.