IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs), detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration is maintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved.

A search for TeV-PeV muon neutrinos from unresolved sources was performed on AMANDA-II data collected between 2000 and 2003 with an equivalent live time of 807 days. This diffuse analysis sought to find an extraterrestrial neutrino flux from sources with nonthermal components. The signal is expected to have a harder spectrum than the atmospheric muon and neutrino backgrounds. Since no excess of events was seen in the data over the expected background, an upper limit of E-2 Phi(90%C.L.)< 7.4x10(-8) GeV cm(-2) s(-1) sr(-1) is placed on the diffuse flux of muon neutrinos with a Phi proportional to E-2 spectrum in the energy range 16 TeV to 2.5 PeV. This is currently the most sensitive Phi proportional to E-2 diffuse astrophysical neutrino limit. We also set upper limits for astrophysical and prompt neutrino models, all of which have spectra different from Phi proportional to E-2.

In order to increase the accelerating gradient, the next-generation of Superconducting Radio Frequency (SRF) cavities will be operated with superfluid helium cooling. This upgrade requires the development of a state-of-the-art cryogenic temperature mapping system, which can be used to identify quench initiation in new cavities, and thereby assess their suitability for installation. This paper presents a new mapping system based on an array of Transition Edge Sensors (TESs): electrical devices that exploit the superconducting transition of a thin film to identify temperature changes.The TES array is manufactured using photolithography to deposit a thin film on a 100 mm diameter glass wafer. Two different designs of Au-Sn TES have been assessed; Design 1 was composed of a 10 nm Cr adhesive layer, followed by 20 nm of Au and 100 nm of Sn, and Design 2 was identical except that the Cr layer was not applied.Design 1 showed excellent film adherence, however no superconducting transition was observed. In contrast, Design 2 showed poor film bonding but a superconducting transition. These insights are being used to design a new cryogenic temperature mapping device that combines Design 1 for robust electrical contacts and Design 2 for second sound detection.

A search for TeV-PeV muon neutrinos with AMANDA-II data collected between 2000 and 2003 established an upper limit of E 2 90%C:L: < 7:4 10 ÿ8 GeV cm ÿ2 s ÿ1 sr ÿ1 on the diffuse flux of extraterrestrial muon neutrinos with a / E ÿ2 spectrum between 16 TeV and 2.5 PeV.The upper limit calculation correctly included event simulations and remains as stated.However, the calculation of the detector's efficiency, which is based only on simulations, was incorrectly tabulated in an appendix and shown in a figure.The values were approximately a factor of 10 too high, although the exact error varies in each bin.The correction has been applied in Tables I and II and Fig. 1.The effective area is the equivalent area over which the detector would be 100% efficient for detecting neutrinos.The typical uncertainty on the effective area from simulation statistics is lowest between 10 5 GeV and 10 6 GeV (2%).The uncertainty increases to 6% at 10 4 GeV and 5% around 10 7 GeV.In the remainder of this document, the number of optical modules (OMs) triggered during an event is referred to as N ch and cos t refers to the cosine of the simulated (true) zenith angle of an event.The term angle-averaged indicates that results are averaged over t between 100 and 180 .All other results reported in the paper, including the upper limit, remain unchanged.

The IceCube neutrino detector is a cubic kilometer TeV to PeV neutrino detector under construction at the geographic South Pole. The dominant population of neutrinos detected in IceCube is due to meson decay in cosmic-ray air showers. These atmospheric neutrinos are relatively well understood and serve as a calibration and verification tool for the new detector. In 2006, the detector was approximately 10% completed, and we report on data acquired from the detector in this configuration. We observe an atmospheric neutrino signal consistent with expectations, demonstrating that the IceCube detector is capable of identifying neutrino events. In the first 137.4 days of livetime, 234 neutrino candidates were selected with an expectation of 211 {+-} 76.1(syst.) {+-} 14.5(stat.) events from atmospheric neutrinos.

We report the results of a five-year survey of the northern sky to search for point sources of high energy neutrinos. The search was performed on the data collected with the AMANDA-II neutrino telescope in the years 2000 to 2004, with a live time of 1001 days. The sample of selected events consists of 4282 upward going muon tracks with high reconstruction quality and an energy larger than about 100 GeV. We found no indication of point sources of neutrinos and set 90% confidence level flux upper limits for an all-sky search and also for a catalog of 32 selected sources. For the all-sky search, our average (over declination and right ascension) experimentally observed upper limit Phi(0)=(E/1 TeV)(gamma)center dot d Phi/dE to a point source flux of muon and tau neutrino (detected as muons arising from taus) is Phi(nu mu)+nu(0)(mu)+Phi(nu tau)+nu(0)(tau)=11.1x 10(-11) TeV-1 cm(-2) s(-1), in the energy range between 1.6 TeV and 2.5 PeV for a flavor ratio Phi(nu mu)+nu(0)(mu)/Phi(nu tau)+nu(0)(tau)=1 and assuming a spectral index gamma=2. It should be noticed that this is the first time we set upper limits to the flux of muon and tau neutrinos. In previous papers we provided muon neutrino upper limits only neglecting the sensitivity to a signal from tau neutrinos, which improves the limits by 10% to 16%. The value of the average upper limit presented in this work corresponds to twice the limit on the muon neutrino flux Phi(nu mu)+nu(0)(mu)=5.5x10(-11) TeV-1 cm(-2) s(-1). A stacking analysis for preselected active galactic nuclei and a search based on the angular separation of the events were also performed. We report the most stringent flux upper limits to date, including the results of a detailed assessment of systematic uncertainties.

On 27 December 2004, a giant gamma flare from the Soft Gamma-Ray Repeater 1806-20 saturated many satellite gamma-ray detectors, being the brightest transient event ever observed in the Galaxy. AMANDA-II was used to search for down-going muons indicative of high-energy gammas and/or neutrinos from this object. The data revealed no significant signal, so upper limits (at 90% C.L.) on the normalization constant were set: 0.05(0.5) TeV-1 m;{-2} s;{-1} for gamma=-1.47 (-2) in the gamma flux and 0.4(6.1) TeV-1 m;{-2} s;{-1} for gamma=-1.47 (-2) in the high-energy neutrino flux.

A search has been performed for nearly vertically upgoing neutrino-induced muons with the Antarctic Muon And Neutrino Detector Array (AMANDA), using data taken over the three year period 1997–99. No excess above the expected atmospheric neutrino background has been found. Upper limits at 90% confidence level have been set on the annihilation rate of neutralinos at the center of the Earth, as well as on the muon flux at AMANDA induced by neutrinos created by the annihilation products.

The sensitivity of a search for sources of TeV neutrinos can be improved by grouping potential sources together into generic classes in a procedure that is known as source stacking. In this paper, we define catalogs of Active Galactic Nuclei (AGN) and use them to perform a source stacking analysis. The grouping of AGN into classes is done in two steps: first, AGN classes are defined, then, sources to be stacked are selected assuming that a potential neutrino flux is linearly correlated with the photon luminosity in a certain energy band (radio, IR, optical, keV, GeV, TeV). Lacking any secure detailed knowledge on neutrino production in AGN, this correlation is motivated by hadronic AGN models, as briefly reviewed in this paper. The source stacking search for neutrinos from generic AGN classes is illustrated using the data collected by the AMANDA-II high energy neutrino detector during the year 2000. No significant excess for any of the suggested groups was found.

The first sensors of the IceCube neutrino observatory were deployed at the South Pole during the austral summer of 2004-05 and have been producing data since February 2005. One string of 60 sensors buried in the ice and a surface array of 8 ice Cherenkov tanks took data until December 2005 when deployment of the next set of strings and tanks began. We have analyzed these data, demonstrating that the performance of the system meets or exceeds design requirements. Times are determined across the whole array to a relative precision of better than 3 nanoseconds, allowing reconstruction of muon tracks and light bursts in the ice, of air-showers in the surface array and of events seen in coincidence by surface and deep-ice detectors separated by up to 2.5 km.

In this document we collect the 18 contributions of the IceCube Collaboration to the 29th International Cosmic Ray Conference (ICRC 2005), Pune, India, Aug. 2005