Administrative coordination in Geneva: Carla Rachman, Resident Director
Directed research coordination CERN: Prof. A. Heister
ATLAS
Spring 2010 internship project of Andrea Welsh and Max Yellen: One important aspect is the calibration the Monitored Drift Tube (MDT) chambers of the Muon Spectrometer. The calibration of the tubes of the MDT chambers are important in measuring the momentum of muons. The measurement of charge deposited by muons when they pass through the MDT chambers can be used to improve the quality of the signal the muons generate when they pass through individual MDT tubes. Calibrating the MDTs can be done by studying data from the front-end electronics measuring time and charge information of the signal. By studying time to digital converter (TDC) and analog to digital converter (ADC) spectrums, spatial resolution can be improved by learning how to reject noise and background hits.
CMS
Spring 2010 internship project of Ashley Rubinstein and Michael Hedges: This semester we studied efficiencies of CMS’s level one triggering system. The level one triggering system is the first step in weeding out bad events from collisions. It reduces the input rate from 10^9 Hz to 100 kHz using custom electronics. In the beginning of the semester, we were given a configuration file, which sends events down different “paths”. Events either pass or fail when going down these paths. We then worked on a code that takes output from running the configuration file and calculates efficiencies. Later, we used the CMS Remote Analysis Builder (CRAB) to run our configuration files on millions of events on computers all around the world. By the end of the semester we were using ROOT to make plots of particular efficiencies for the L1 triggering system.
Spring 2010 internship project of Mike Lloyd: During my time at CERN, I dealt with hardware involved in the Hadron Calorimeter. Silicon Photomultipliers (SiPM’s) are a key aspect to this experiment. SiPM’s utilize the photovoltaic effect to detect photons that result indirectly from events occurring in the LHC. These devices are loaded with unwanted phenomena that result in false detections. The imperfections are due to fundamental physical constraints and cannot be completely eliminated. However, if the properties of a SiPM are well known, it is possible to accurately recreate events with the information that the SiPM collects. Under the guidance of Iouri Musienko, I worked on SiPM detection simulations that took into account several issues that could lead to unwanted, misleading signals in the devices. The simulations act as an accurate model for what will be detected given a certain input, providing a means of determining what actually takes place for a given experimental event.
T2K
Spring 2010 internship project of Chelsea Bartram: As part of the T2K neutrino group, I will replicate the results acquired by Fanny Dufour in the following paper: F. Dufour, T. Kajita, E. Kearns, and K. Okumura. “Further Study of Neutrino Oscillation with two detectors in Kamioka and Korea”. The purpose of this proposed experiment is to measure the mass hierarchy of neutrinos and the CP violating phase. CP violation, or charge-parity violation, indicates that some symmetry in the laws of physics has been undermined. The authors devised their own software in order to account for the energy response of a water Cherenkov detector as accurately as possible. The simulations described in this paper made reference to a custom made computer program written by F Dufour. The software package GLoBES (created specifically for neutrino physics experiments)will be used to verify the results and compare them to those presented in the paper.
The following link may be of interest: link
NA62
Spring 2012 Internship Project of Bertie Wright (’13): I am working with the NA62 research group attempting to accurately measure the branching ratio of the decay of the positive Kaon into positive Pion plus neutrino/anti-neutrino pair. I am working most closely with Augusto Ceccucci, the project leader and Antonino Sergi, a senior physicist. My role in the experiment (with fellow student, Kevin Merenda) is to write software for analyzing data coming from the prototype of the main straw detector. The straws themselves serve as the detector; they are filled with an AR/CO2 gas mixture and have a high voltage wire running down the center. I am also writing analysis software for an independent detector called the MicroMegas detector. This software package will be able to present statistics (in the form of histograms) and execute track reconstruction of the particles path through the various detectors. The software we create for this prototype will then be used as part of the main software package for the NA62 Reconstruction.