Decommissioning SciBooNE

We have just done something on SciBooNE that has become somewhat rare in the field these days: we turned off the detector intentionally! On 18 August 2008, the SciBooNE neutrino beam data run offically ended at 08:00 in the morning (CDT). It seems like only yesterday that we put SciBooNE together and observed the first neutrino events in the detector, but we have now finished all the data-taking and have decommissioned the detector. Many of the detector components will be returned to their respective owners, but the main bulky parts will remain the detector hall until someone else decides to use the parts or the hall.

When most people learn that we decided to end the run, they are puzzled and ask why, apparently in the belief that we must have been forced to end the run. In fact, we ended the run mainly because we have already collected all the data we need to achieve the physics goals we set out to achieve, and it's now time to concentrate on the analysis of the data. Far from being a sad occasion, it was actually rather triumphant. (You can see how happy our Run Coordinator Hidekazu Tanaka, Columbia University, was to end the run in the photo at right. Also shown in the photo is Zelimir Djurcic, Columbia, who was the last SciBooNE shifter. (Photo courtesy of Hideyuki Takei.)

We spent a couple of weeks dismantling everything in the detector hall and sorting out all the parts for shipment back to their places of origin. As usual for us, most of that work was done ahead of schedule. To help out with the work, many of our collaborators came to the lab, and we had a large influx of young students as well. In the photo at left you can see several SciBooNErs working on removing the multi-anode photomultipliers from the top side of SciBar. From left to right are Yuki Kobayashi and Shunsuke Masuike, Tokyo Institute of Technology, co-spokesperson Tsuyoshi Nakaya, Kyoto University, Joan Catala Perez, University of Valencia, and in front is Katsuki Hiraide, Kyoto University. (Photo courtesy of Reidar Hahn.)

Yuki and Shunsuke are two M.S. students who came to Fermilab (and America) for the first time just to help with the decommissioning, and Joan and Katsuki are two of our PhD students and they've both been out at Fermilab for years building and operating the detector and of course working on data analysis. Actually, Katsuki recently presented our first preliminary physics result at the ICHEP08 conference in Philadelphia, PA. You can see him in front of a pretty large audience of neutrino physicists presenting the result in the photo at right. (Photo courtesy of Herman White.)

To commemorate and celebrate the end of the run we threw a big party at Fermilab on 22 Aug. You can see the invitation to the party up at the top of this entry. (The photo in the

invitation is courtesy of Reidar Hahn.) We had a nice simple cookout and a friendly game of volleyball which, unfortunately, the SciBooNE team lost to the MiniBooNE team. I guess we can't win them all...

(Photo courtesy of Joan Catala Perez.)

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!