15 April 2007

The IOP conference

This years IOP conference took place from the 3-5 April at the University of Surrey . For anyone who's not familiar with the conference it's aimed at getting all the final year students to give a conference talk before the end of their PhDs. It's also a very good excuse to get the students and lots of the staff from all the groups over the country together for a few (!) drinks.

Somehow, and I'm still not sure how, I managed to end up responsible for everyones paperwork. For any current second year students out there I'd avoid this at all costs! It took 24 forms, one lost cheque and a lot of chasing but finally we were registered.

The week before the IOP conference we're expected to give a practice run in front of the group at Imperial. I think it's fair to say that whilst this was incredibly useful it was also totally disheartening, probably for the staff as well after 7 hours! The most important lesson for me seemed to be that as I'd gotten used to giving collaboration talks I'd also picked up some really bad habits. The biggest criticsims, providing far too much information on the slides and my use of complete scentences.

The real thing, strangely, was a lot less scary (even in the main lecture theatre) and despite all my complaints beforehand about ending up in a session with mainly ZEUS students, I actually really enjoyed it. In fact the talks I enjoyed most were nearly always from the running experiments. I guess it's good to see something other than MC studies for once. The downside was that everyone was there for these talks and few people showed interest in the two LHCb talks tagged on at the end.

It was really good to catch up with everyone else in my year and I've probably learnt a fair bit from all the talks but I'm glad it all only happens once!

12 April 2007

Bye Bye Imperial College

Friends and family are sometimes amazed when I describe how the career path in particle physics works. I think this is quite an interesting subject and also different than many other careers, so I thought I would create a post on this. This is particularly relevant as I have just changed jobs. So for this one time we will not talk about physics but instead about what it is like to do physics.

Particle physics is a very international field. For example I grew up in Amsterdam, the Netherlands, where I also did my undergraduate studies. When I graduated I decided continue study for my Ph.D. in Amsterdam, at NIKHEF. About half of my five-year Ph.D. I spent in Chicago, working at Fermilab. Once I received my Ph.D. I accepted a contract for two years at Imperial College, as a research associate. Young researchers that are not lecturers or readers yet are usually referred to as Post-docs. This has to do with the fact that they already have their doctorate. I recently accepted a more advanced post-doc position with Cornell University. Even though Cornell University is based in Ithaca, New York, USA, I actually will live and work in Geneva, at CERN. The next step in my career probably would be to become a member of staff at some university. I am very much looking forward to that, as it would involve teaching and working with students.

One of the interesting things is that during all this time I was working in large international collaborations, so there really is not much difference except for the location and your direct colleagues. I think that if you ask a random particle physicist they will tell you that their work is so international that location really does not make a difference any more. I now have just started a new job and besides having moved to a different country the only change I've noticed is that being closer to the detector project I work on makes life much easier. Oh and the fact that the weather is better in Geneva, of course!

I love my job and the traveling is one of the additional advantages (besides doing something fun, interesting, challenging, with motivated colleagues in an international environment)

11 April 2007

Opened Box


Well, the big moment is about to arrive. More than a decade ago, the LSND collaboration shook up the particle physics world by announcing a neutrino (actually, antineutrino) oscillation result whose interpretation requires physics beyond the standard model. As I wrote in a previous entry, I am on MiniBooNE which has been working on a blind analysis to confirm or refute the LSND result for the past ten years. We have been pushing very hard to "open the box" and see what the answer is for quite a while and it has finally happened.

Our box opening procedure was a four step process in which each step was designed to reveal enough information that we could decide if things were working correctly, but not enough information to tell us the answer. Thus blindness was preserved until the final step. Our procedure was designed so that if a problem were to be found in one of the early steps, we could stop the procedure and try to fix the problem, before starting over again. Doing that would be OK as long as we did not reveal any information about the contents of the box.

Today at Fermilab, our first oscillation result will finally be announced, and tomorrow I will give a seminar on the result myself here at Imperial. I can't say what the answer is yet, so you'll have to come to my seminar to find out!

As an interesting side note, we did have to stop the box opening procedure and start over again, so it was a very good thing that we had this procedure. We attempted a box opening in February, over the weekend when I wrote my blind analysis blog entry, and discovered a reason to abort the process and regroup. But a full entry about that will have to wait until the result is announced to the world. Right now, I have to complete my seminar!

08 April 2007

Big Bang exhibition at the Science Museum

Some time ago I wrote about Fieldwork for the Science Museum and promised some updates. Back in February we were trying to repair an old spark chamber for an exhibition about the LHC at the Science Museum. The exhibition is now open but the spark chamber isn't there.

Dave spent a lot of time trying to repair the spark chamber and there is still a hope that it will go to the Science Museum. But it missed the deadline for the exhibition opening. The problem was with the trigger. The chamber is activated by two huge scintillators which produce a signal when a charged particle crosses. One is mounted below the chamber, the other is on top of it (it's the kind of gnu horns you can see on the picture in the original post). All the light guides (that guide the scintillation light to the photomultipliers) are broken. They can be repaired but that takes some time. Dave is working on that. As for the chamber itself, it looks OK. It produces nice sparks when activated by an almost random trigger.


The exhibition is essentially a huge cube of 5m size explaining in four zones what the LHC is about, how it works, how the detectors work and how the data will be analyzed. Or, well, as the exhibition is aimed at 14 to 17 year olds, it does not explain that much but gets a feel for how complicated and huge it is. The exhibition is actually called Big Bang (and that's what you'd read from the distance), as it's about recreating the conditions of the Big Bang in a laboratory. The illustrator made a great job drawing particles and collisions. I love his drawing of a cavern with all the ongoing activity! I won't say more. Come to the Science Museum (it's free) and see it.

The whole design process started (for me) in December where I attended a day long brainstorming session with 20 more physicists from various places in the UK. The team from the Science Museum was quite impressive at extracting as much information and ideas from us as they could. Of course many of them were not feasible, like putting a 1:1 picture of Atlas on the wall (rejected as it wouldn't fit: the museum is much too small!) or putting a real Grid node in the museum. Instead there's a lot of graphics, animations and small movies.

Then for several months we got spammed by the designer teams sending us text snippets to check for scientific accuracy. A month ago there was a meeting with the designer who explained us his ideas for the layout. Scientists and designers: two worlds collide... But we eventually managed to speak a common language.


Three weeks ago I got a mail asking if I was happy to be quoted in the exhibition saying "These high-energy collisions will replicate the conditions that occurred in the moments after the Big Bang, 13 billion years ago". I don't remember having ever said that and would have said 14 anyway... They obviously got a lot of quotes from the brainstorming session and wanted to match them with real scientists. So I agreed provided they change the age of the Universe (!). The result is shown in the picture.

01 April 2007

The National Particle Physics Masterclass

Last Wednesday we organised our traditional annual masterclass (see web-page). Practically this means we invite 120 A-level students having chosen physics as one of their main subjects (and therefore hopefully interested) and talk about particle physics during an afternoon.

We had four lectures about antimatter (Patrick), Higgs searches (Gavin), neutrino oscillations (Yoshi) and solar neutrinos (Dave) and a discussion session where students could ask a lot of questions ranging from "Why do you like particle physics?" to "Can you explain Bell inequalities in 5 minutes?". If there's any question still unanswered don't hesitate to post it on this blog using the "Read/Add comments" link below.

The masterclass went quite smoothly, given that the air-conditioning decided to die during the morning, which forced us to reshuffle the order of the breaks a little. There's no real fun if there's not a little touch of improvisation in the organisation!

I had a first look at the feedback questionnaires. The students most liked the discussions and Dave's talk. We also had a lot of praise for the catering.

Among the suggestions for improvement of course the air conditioning was mentioned, as well as a need for more breaks (we'll take that into account for next year for sure!). Then we had a lot of of interesting but sometimes contradictory suggestions for "more" and "less theory", "more demonstrations" (yes, I agree, but that's difficult to organize) and "some derivations" (that's a tough one...). Many thanks to the students for all the useful feedback!

I would also like to thank all my colleagues who worked to make this happen: First Piera for all practical aspects. Paula and Ghislaine for the help with the catering. The already mentioned speakers of course, and everyone who joined the discussions. I can't possibly cite them all here!