News
April 25, 2007 - Tracks!
After several attempts over the past few months, we have successfully observed cosmic ray tracks inside of our TPC! The image at right shows a hadronic shower as seen on the collection plane of our TPC. The horizontal axis is time lapsed since an initial trigger, while the vertical axis represents wire number within the collection plane.
We have made several changes to our setup since the last entry, including installation of a purity monitor inside of our cryostat, which has allowed us to observe the purity of our liquid argon as we perform searches for cosmic ray events.
April 11, 2007 - MiniBooNE result
On March 26, 2007, the we decided to open the MiniBooNE data box. Two weeks later on April 11, 2007, we presented our preliminary results at Fermi National Accelerator Laboratory and published these results in Physics Review Letters.
January 15, 2007 - TPC Test #2
We have made our second attempt at filling the cryostat with argon and looking for tracks in the TPC. We did not observe any tracks, but great progress was made in debugging the system.
Better grounding of the elcectronic racks noticeably reduced the noise present in the DAQ system and allowed us to see test pulse signals very well. Our first attempt at a high voltage filter also showed some signs of reducing the noise.
January 11, 2007 - Argon Purity
We have finally been able to observe the signature of argon purification in our lab. This is an important and vital step towards seeing tracks from cosmic rays in the liquid argon TPC we have built.
The image shows the combined cathode and anode signals from our ICARUS purity monitor. The anode signal here is 2/3 of the cathode signal, with a drift time of approximately 150 microseconds. The estimated lifetime of electrons in this purified argon is 300-400 microseconds, which is well above the requirements needed for our TPC.
December 7, 2006 - Filling Soon!
We have now sealed up the tank and are eagerly awaiting Alessndro’s return from Italy so that we can begin filling the tank and hopefully see tracks. However, before we start filling, we still need to do another purity test, better understand the Labview data acquisition program, and decide how we are going to trigger.
The people at Fermilab are sending us regenerated filters to conduct the purity test with and some scintillator to fashion a triggering system.