27 June 2007

To What End?

Hello everyone, I've been thinking about what to post and looking at all the blog entries in the Imperial College HEP blog spot, it is obvious that the majority deal directly with the various HEP experiments carried out here at Imperial or with the HEP group itself. So I've decided to go the other direction - write on stuff that is indirectly related to HEP.

Of the long list of questions that I find interesting to mull over every now and again, I guess one of the more important ones would be my desire to understand the role of HEP in contributing to the well-being of society. Think about it; of what use is HEP to the day-to-day dynamics of society. When I leave the office and am out with my friends how does HEP contribute to my life? If I'm out shopping, sightseeing maybe, how does HEP contribute? Or if I'm simply spending time with family how does HEP contribute to how I interact with them? Another way to look at it would be to ask: how does HEP contribute to my understanding of myself as an independent entity with a role in society?

These questions are not asking about the opportunities that arise from working in a HEP environment such as travelling, attending conferences and the like. They are asking about the intrinsic purpose of HEP with respect to humanity's existence in the sea of creation. To answer, perhaps a good starting point would be to take a step back and try to figure out why HEP and indeed all institutions of knowledge became necessary in the first place.

The first important clue is that every human endeavour, be it Science, Technology, The Arts, Economics or Religion has as its original goal the desire to study and understand the human being, the environment or the interaction between the two, where the environment in this case refers to all physical creation that is separate from the human being, i.e. the earth, the universe, and so on.

The second clue is that a system, any natural system, will be composed of elements that are each unique. The uniqueness of each element automatically generates the property of diversity within the system. In a system that is composed of sentient, self-aware elements, for example human beings, this leads to the phenomena of demand under which each element recognizes its deficiencies relative to the strengths of the other elements within the system and reacts to this by striving to address the balance.

The third clue is that the act of striving is a natural action that is induced and controlled by the principle of evolution that permeates all creation.

And so combining clues 1, 2 and 3, we are left with the conclusion that HEP and indeed any other human endeavour exists for no other reason than to serve the phenomena of demand which is itself a natural attribute that is inherent within any system in creation. This is a sweeping statement. And it is one that raises a lot questions foremost of which are: What is demand? What is evolution? How are they defined and what are their origins? The answers to these questions become of even greater importance in the face of the realisation that there is still much that is unknown by the various institutions of knowledge in their attempts to plumb the depths of the mysteries of man and the environment. Society today is a paradox. It is the epitome of good health - evidenced by the immense technological progress over the last couple of decades, the space age, ground breaking discoveries, etc and yet it appears on the brink of imploding - evidenced by poverty, war and consumerism. How did it all go wrong?

The list of questions can be endless, but inevitably they are all tied in to a common theme - the origin, purpose and future of the human being in the cosmos. As it is today, humanity finds herself in real danger of completely missing the big picture as she concentrates on moving further and further down the path of the individual disciplines in search of the Holy Grail. What should be done to correct this imbalance?

I'll stop at this point and open the floor to comments. I must point out that this blog is somewhat of a teaser. All the questions have answers, no surprise there! However, the point of this blog is to emphasise the fact that HEP and indeed any other discipline in any of the institutions of knowledge exists only to serve demand. And so perhaps the key for maximizing the potential of HEP would depend on understanding fully what demand entails.

22 June 2007

The Bubble Chamber Football Tournament (including results)

This year's Bubble Chamber Football Tournament is on Saturday 23 June, at UCL's training grounds somewhere in North London.

The tournament was inaugurated decades ago by university groups in the UK who worked with Bubble Chambers, the main tool used in particle physics experimentation in the '60s and '70s, which provided the most stunning images of particle interactions.


The participants are, allegedly:

UCL x2
Bristol
Imperial
Manchester
Birmingham
Cambridge
Exiles?
Misfits?

You could say it is a bit like the Ivy League, except it is proper football and Bubble Chambers are a lot cooler than Ivy.

Neither of the two American universities that I have been associated with in the past, MIT and Stanford, are in the Ivy League, and definitely had a long history of working with Bubble Chambers.

I am sure that if they would like to send some teams over to the UK next year, they would be welcome to join the Bubble Chamber group of universities!

The Imperial team has been practising for the last few months, every week on Wednesdays. I can't say much more here, because our formation and free kick strategies are top secret, but I'll just say that with his dazzling white boots, smart kit, and incredible pace, you might have thought that Wayne Andrews was playing for us on the wing. Just don't tell the other teams that he (our winger, I mean) is a donkey!



The Imperial College High Energy Physics Football Team


Saturday was a great day out, with all the teams arriving more-or-less on time and the weather holding out till just before the final kick of the afternoon.

We started out losing 1-0 to Bristol in the first match of the group stage, but since this was the first time the Imperial team had actually played together ("practice sessions" notwithstanding), we weren't too disappointed. The Bristol players had clearly met the rest of their team before Saturday.

The highlight of the day was the Central London Derby, our second match, which ended
Imperial College London 6 - 0 UCL

Personally, I think it was my tight man-marking of their right winger (and goalie) "J.B." which ensured our clean sheet.

We then went on to beat Manchester 2 - 0, and at the end of group stage the table ended up like this:

Pts GD
Imperial 6 +7
Bristol 6 +2
Manchester 6 +1
UCL 0 -10

After this some more matches were played, Birmingham won, and Cambridge (not UCL) got the wooden spoon, known (for purely historical reasons as far as I could tell) The Troll.

Next year's tournament will be at Manchester, to which there are cheap direct flights from Boston....

11 June 2007

SciBooNE or: How I learned to stop worrying and love the MRD


After many months of cajoling, I feel that I should write a blog entry on what I have been doing whilst living out here in the USA other than enjoying their fine beers, moderately sized meals and small economic vehicles.

I suppose I should first explain how I came to work on SciBooNE in the first place. In January 2006 I joined the T2K group my supervisor, Morgan Wascko, a new lecturer joining the group. As it turned out Morgan was also co-spokesperson on the SciBooNE experiment which at that stage was a proposed experiment to be built out at Fermilab to measure sub-GeV neutrino cross-sections of interest to T2K. After some discussion it was decided that this would be a good opportunity for me to get some hardware experience by going out to Fermilab and helping in the construction of one particular element of the detector, namely the Muon Range Detector (MRD).

The MRD is an iron-scintillator sandwich detector consisting of 13 alternating horizontal and vertical layers of counters separated by 5cm of iron. The total depth of iron in the detector is 60cm which corresponds to stopping a 900MeV muon. The purpose of the MRD is to measure the energies of muons produced in neutrino interactions, for example charged current quasi-elastic (CCQE), where a muon and a proton (muon neutrino) or neutron (muon anti-neutrino) are produced. By measuring the muon energy the neutrino energy can be reconstructed.

In May 2006 I visited Fermilab for 1 month to construct and test the prototype counter design for the MRD. By June the design had been approved and mass counter assembly could begin.
I returned to Fermilab in July this time to assist in the full counter assembly which got underway at the beginning of that month. With 362 counters to be made and 3 days needed for each counter to be produced this would be the largest single job for the MRD construction. The final counters were finished in December just in time to begin the detector assembly in January. At this stage it was decided that I should move to the States to help complete the detector construction and to see it through the beginnings of its data run.

The MRD is a unique detector in the fact that it is almost completely constructed from previously used materials. The scintillator panels (20cm x 155cm x 0.6cm) were taken from an earlier Fermilab experiment whilst 5 different photomultiplier tube (PMT) flavours are used to readout these counters. The iron having enjoyed a number of years outside in the elements had to be cleaned before it was ready to be used. Even some of the cables, both high voltage and signal, had been previously used. When it came to inspect these cables, in storage in a disused detector hall, they were found in a mess, you could say a ratsnest, not so much because the cables were tangled but rather a ratsnest! As 2 grad-students went about untangling the cables two 'rats' (though they could have been large mice) emerged from their makeshift home. Needless to say this added considerable time to the cable inpections as every inch had to be checked for damage and a number were rejected having been partially chewed!
The PMTs have a range of ages, from relatively new tubes used in the KTeV and NuTeV experiments, to RCA tubes that date to the early 70's and no doubt have been used in a number of different experiments over the years. As you can imagine this produces particular problems when it comes to understanding your detector efficiencies. It is a credit to all those involved in the construction that when the detector was switched on in May 2007 only 3 of the 362 channels were found to be dead, well below our expectations.

In January the detector construction got underway in Lab F on the Fermilab site. At this stage SciBooNE, a supposedly small experiment, was starting to sprawl. Office spaces could be found in Wilson Hall, the CDF trailer and the main CDF building. As for the detector construction, the CDF pit was devoted to SciBar and the EC whilst the MRD had spaces at Lab F and Lab 6 not to mention cable repairs taking place at the D0 hall and the civil construction of the SciBooNE hall in the Booster neutrino beamline. SciBooNE was maturing fast and with the aggressive schedule put forward the hope was to see a completed detector by early June in time to commission before the proposed shutdown in August.

The MRD construction proved to be a challenge. Initially the first few planes proved trivial to construct. However as more and more planes were added to the frame so the space between planes diminished. By the time the detector was completed the space between planes was 30cm (the depth of a fermilab standard issue hardhat!) Unfortunately by this stage the american portions had got the better of myself and Nakaji (nickname: 'The Blackhole') and so it was to the smallest of our collaborators, Kendall Mahn (5' 2") to complete the work. We looked on eating doughnuts (raspberry cream I believe).

The detector construction was completed in March and was partially cabled allowing us to test the DAQ system with one week of cosmic data. The move date was set for 23rd April, and so it was apt that "Once more into the breech" was mentioned more than once that day as a 360 ton crane lowered, i've been told i'm not allowed to say dropped, the MRD into place. SciBar and the EC were lowered 2 days later.

At this stage a number of tasks in the detector hall had to be undertaken and it was hoped that the MRD cabling would begin around the 25th May and be completed by early June. However with NuInt, a neutrino interactions conference, to be held at Fermilab from 30th May until 3rd June it was with a last gasp of energy that we pushed to complete the cabling early so as to show beam events at the conference. As you can see from Morgans post we succeeded in doing so but I think it is an astonishing feat that we completed the cabling of the detector on the 24th May, 1 day before we were meant to start!

I hope this has given you a little insight into SciBooNE and the MRD, I personally feel that it is astonishing that such detectors, both SciBar/EC and the MRD, can be constructed in such a short space of time. In a little more than a year a detector went from merely a blueprint with a counter design that had yet to be confirmed as suitable, to a detector taking data. SciBars timeline is equally incredible given that it was shipped in from Japan and had to be reconstructed with a new support frame and DAQ system. It has been a great experience to work in such a dynamic collaboration, I hope this continues. All SciBooNE collaborators must be congratulated for all their hard work.

P.S. I am in the process of making a website where I will be posting photos of the MRD construction among other things T2K/SciBooNE related. I will post a link in due course.

08 June 2007

First Neutrinos in SciBooNE

I am the co-spokesperson of SciBooNE, Fermilab's newest neutrino experiment. We have a small detector with fine-grained tracking capability (for a neutrino experiment) placed 100m from the beam target of the Booster Neutrtino Beam, which is the same beam that sends neutrinos to MiniBooNE. We've just crossed the latest and most exciting of a series of significant milestones: recording our first neutrino events! Early last week, our Run Coordinator Masashi Yokoyama from Kyoto University, led the SciBooNE graduate students on an all-nighter so we could record a neutrino event or two in time for the NuInt07 conference at Fermilab. The results were fantastic, and one example is shown at right.

The picture is a top-view event display of our first neutrino interaction with energy deposited in all three detector subsystems. The green field at left represents the SciBar detector, which is made of plastic scintillators with wavelength shifting fibers read out by multi-anode PMTS. The traced square and rectangles in the middle represent the Electron Catcher (EC), which is a lead/scintillating fibre EM calorimeter. The beige strips with small green trim at right represent the Muon Range Detector, which is made of 5 cm iron planes interspersed with plastic scintillators paddles read out by 2-inch PMTs. Maybe Joe will write a blog entry to describe what the MRD does; he knows all about it since he built it! Anyway, the event appears to be a single mu+ track from a muon-antineutrino. In the display, the red dots in SciBar represent strips that registered PMT hits, and the size of the dot is proportional to the amount of charge recorded. The horizontal blue and red lines next to the EC show the amount of charge read out by the EC PMTs (the EC modules are read out on both sides) and are consistent with a MIP. The MRD squares represent scintillators that were hit; we can see that the muon penetrated at least 7 of the iron planes.

Although we have identical readout systems for the side view, we were not running those channels when this event was recorded because the cooling systems were not yet fully operational. They are operational now, and we should be ready for stable beam operations by early next week.

It's a very exciting time for SciBooNE!