Bi-Weekly IIHE Internal Seminar: David Heereman, "An improved data acquisition system for supernova detection with IceCube: HitSpooling"

Monday 24 Jun 2013, 14:00 → 15:00 Europe/Brussels

Small Seminar Room (Universe)

With an array of 5160 photomultiplier tubes, IceCube monitors one cubic kilometer of deep Antarctic ice at the geographic South Pole. Neutrinos are detected via the Cherenkov photons emitted by charged secondaries from their interactions in matter. Due to low ice temperatures, the photomultipliers dark noise rates are particularly low. Therefore a collective rate enhancement introduced by interacting neutrinos in all photomultipliers can be used to search for the signal of galactic core collapse supernovae, even though each individual neutrino interaction is sub-threshold for forming a trigger. At present, rates of individual photomultipliers are recorded in 1.6384 ms intervals which limits the time resolution and does not allow to exploit signal correlations between the sensors. An extension to the standard data acquisition, called HitSpooling, overcomes these limitations by buffering the full raw data stream from the photomultipliers for a limited time. Thus, the full set of data can be analyzed when a supernova occurs, allowing for the determination of the average neutrino energy and the analysis of the fine time structure of the neutrino light curve. The HitSpooling system will also significantly help in understanding the noise behavior of the detector and reduce the background induced by atmospheric neutrinos to the supernova analysis.