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R. Nahnhauer

Publications and source records attributed to R. Nahnhauer.

14 recordsLinked to original sources
arXiv2014

Introducing TAXI: a Transportable Array for eXtremely large area Instrumentation studies

A common challenge in many experiments in high-energy astroparticle physics is the need for sparse instrumentation in areas of 100 km2 and above, often in remote and harsh environments. All these arrays have similar requirements for read-out and communication, power generation and distribution, and synchronization. Within the TAXI project we are developing a transportable, modular four-station test-array that allows us to study different approaches to solve the aforementioned problems in the laboratory and in the field. Well-defined interfaces will provide easy interchange of the components to be tested and easy transport and setup will allow in-situ testing at different sites. Every station consists of three well-understood 1 m2 scintillation detectors with nanosecond time resolution, which provide an air shower trigger. An additional sensor, currently a radio antenna for air shower detection in the 100 MHz band, is connected for testing and calibration purposes. We introduce the TAXI project and report the status and performance of the first TAXI station deployed at the Zeuthen site of DESY.

astro-ph.IM↗
arXiv2008

Simulation of a hybrid optical-radio-acoustic neutrino detector at the South Pole

With construction halfway complete, IceCube is already the most sensitive neutrino telescope ever built. A rearrangement of the final holes of IceCube with increased spacing has been discussed recently to optimize the high energy sensitivity of the detector. Extending this baseline with radio and acoustic instrumentation in the same holes could further improve the high energy response. The goal would be both to detect events and to act as a pathfinder for hybrid detection, towards a possible larger hybrid array. Simulation results for such an array are presented here.

astro-ph↗
arXiv2008

Feasibility of acoustic neutrino detection in ice: Design and performance of the South Pole Acoustic Test Setup (SPATS)

The South Pole Acoustic Test Setup (SPATS) has been built to evaluate the acoustic characteristics of the South Pole ice in the 10 to 100 kHz frequency range so that the feasibility and specific design of an acoustic neutrino detection array at South Pole can be evaluated. SPATS consists of three vertical strings that were deployed in the upper 400 meters of the South Pole ice cap in January 2007, using the upper part of IceCube holes. The strings form a triangular array with the longest baseline 421 meters. Each of them has 7 stages with one transmitter and one sensor module. Both are equipped with piezoelectric ceramic elements in order to produce or detect sound. Analog signals are brought to the surface on electric cables where they are digitized by a PC-based data acquisition system. The data from all three strings are collected on a master-PC in a central facility, from which they are sent to the northern hemisphere via a satellite link or locally stored on tape. A technical overview of the SPATS detector and its performance is presented.

astro-ph↗
arXiv2007

Feasibility of acoustic neutrino detection in ice: First results from the South Pole Acoustic Test Setup (SPATS)

Astrophysical neutrinos in the EeV range (particularly those generated by the interaction of cosmic rays with the cosmic microwave background) promise to be a valuable tool to study astrophysics and particle physics at the highest energies. Much could be learned from temporal, spectral, and angular distributions of ~100 events, which could be collected by a detector with ~100 km^3 effective volume in a few years. Scaling the optical Cherenkov technique to this scale is prohibitive. However, using the thick ice sheet available at the South Pole, the radio and acoustic techniques promise to provide sufficient sensitivity with sparse instrumentation. The best strategy may be a hybrid approach combining all three techniques. A new array of acoustic transmitters and sensors, the South Pole Acoustic Test Setup, was installed in three IceCube holes in January 2007. The purpose of SPATS is to measure the attenuation length, background noise, and sound speed for 10-100 kHz acoustic waves. Favorable results would pave the way for a large hybrid array. SPATS is the first array to study the possibility of acoustic neutrino detection in ice, the medium expected to be best for the purpose. First results from SPATS are presented.

astro-ph↗
arXiv2007

Permafrost - An Alternative Target Material for Ultra High Energy Neutrino Detection?

The detection of cosmic neutrinos with energies above 1017 eV got growing interest during recent years. Possible target materials for in-matter arrays of ~100 km3 size under discussion are water, ice and rock salt. Here we propose to investigate permafrost as an additional alternative, covering ~20% of Earth land surface and reaching down to more than 1000 m depth at certain locations. If sufficiently large attenuation lengths for radio and acoustic signals can be demonstrated by in-situ measurements, the construction of a large hybrid array within this material may be possible in the Northern hemisphere. Properties and problems of a possible location in Siberia are discussed below. Some acoustic data are compared to laboratory measurements using "artificial" permafrost.

astro-ph↗
arXiv2005

Simulation of a Hybrid Optical/Radio/Acoustic Extension to IceCube for EeV Neutrino Detection

Astrophysical neutrinos at $\sim$EeV energies promise to be an interesting source for astrophysics and particle physics. Detecting the predicted cosmogenic (``GZK'') neutrinos at 10$^{16}$ - 10$^{20}$ eV would test models of cosmic ray production at these energies and probe particle physics at $\sim$100 TeV center-of-mass energy. While IceCube could detect $\sim$1 GZK event per year, it is necessary to detect 10 or more events per year in order to study temporal, angular, and spectral distributions. The IceCube observatory may be able to achieve such event rates with an extension including optical, radio, and acoustic receivers. We present results from simulating such a hybrid detector.

astro-ph↗
arXiv2000

The H1 Forward Proton Spectrometer at HERA

The forward proton spectrometer is part of the H1 detector at the HERA collider. Protons with energies above 500 GeV and polar angles below 1 mrad can be detected by this spectrometer. The main detector components are scintillating fiber detectors read out by position-sensitive photo-multipliers. These detectors are housed in so-called Roman Pots which allow them to be moved close to the circulating proton beam. Four Roman Pot stations are located at distances between 60 m and 90 m from the interaction point.

hep-ex↗
arXiv1999

Measurements of the radiation hardness of selected scintillating and light guide fiber materials

Radiation hardness studies of KURARAY SCSF-78M scintillating fibers and clear fibers from KURARAY and pol.hi.tech. performed under different dose rate conditions in proton and electron beams are summarized. For high dose rates in-situ measurements of the fiber light output were done. During several months after irradiation all fibers were measured concerning light emission and transparency. Fibers irradiated at high rates to about 1 Mrad are clearly damaged but recover within a few hours up to several weeks. Using smaller rates up to the same integral dose a decrease of the light output of scintillating fibers of up to 30% can not be excluded. Clear fibers seem to be uneffected up to 400 krad. No significant influence of fiber coverage and atmosphere during irradiation was found.

physics.ins-det↗
arXiv1999

A Fiber Detector Radiation Hardness Test

An intense 146 MeV/c pion beam was stopped inside a scintillating fiber detector made out of 12 planes with 16 pixels each, where every pixel consists out of 8 times 8 scintillating fibers of 500 mkm diameter dense packed. The detector was irradiated for 52 hours to more than 1 Mrad at its center. Before and directly after the irradiation the detector has been exposed to a particle beam to compare the corresponding light output. This study was continued during the following three months using cosmic rays. No damage was found taking into account the measurement errors of 5-10 %. In contrast a 9 cm deep lucite degrader became irreversibly non-transparent in the irradiation region.

physics.ins-det↗
arXiv1998

Testrun results from prototype fiber detectors for high rate particle tracking

A fiber detector concept has been realized allowing to registrate particles within less than 100 nsec with a space point precision of about 0.1 mm at low occupancy. Three full size prototypes have been build by different producers and tested at a 3 GeV electron beam at DESY. After 3 m of light guides 8-10 photoelectrons were registrated by multichannel photomultipliers providing an efficiency of more than 99%. Using all available data a resolution of 0.086 mm was measured.

physics.ins-det↗
arXiv1998

Tests of a fiber detector concept for high rate particle tracking

A fiber detector concept is suggested allowing to registrate particles within less than 100 nsec with a space point precision of about 0.1 mm at low occuppancy. The fibers should be radiation hard for 1 Mrad/year. Corresponding prototypes have been build and tested at a 3 GeV electron beam at DESY. Preliminary results of these tests indicate that the design goal for the detector is reached.

physics.ins-det↗
arXiv1998

Fiber technology applications for a future e+e- linear collider detector

The advantages and possibilities of fiber technology for the detection of particles in 500 GeV e+e- reactions are considered. It is suggested to build a fast trigger which could be used also for intermediate tracking. A fiber preshower in front of the electromagnetic calorimeter would allow to identify electrons and photons with a space precision better than 0.1 mm.

physics.ins-det↗
arXiv1997

Development of scintillating fiber detector technology for high rate particle tracking

The performance of a scintillating fiber detector prototype for tracking under high rate conditions is investigated. A spatial resolution of about100 micron is aimed for the detector. Further demands are low occupancy and radiation hardness up to 1 Mrad/year. Fibers with different radii and different wavelengths of the scintillation light from different producers have been extensively tested concerning light output, attenuation length and radiation hardness, with and without coupling them to light guides of different length and diameter. In a testrun at a 3 GeV electron beam the space dependent efficiency and spatial resolution of fiber bundels were measured by means of two external reference detectors with a precision of 50 micron. The light output profile across fiber roads has been determined with the same accuracy. Different technologies were adopted for the construction of tracker modules consisting of 14 layers of 0.5 mm fibers and 0.7 mm pitch. A winding technology provides reliable results to produce later fiber modules of about 25 cm x 25 cm area. We conclude that on the basis of these results a fiber tracker for high rate conditions can be built.

hep-ex↗