The study "Potential and Limits of Independent Living in Private Households" (MuG III) provides a comprehensive picture concerning the life situation of persons in need of help and care within ...private households. Domestic care in Germany is still provided by the family. Professional services within the framework of the Long Term Care Insurance add to domestic care, with the central objective to support the private willingness to home care. Viewed in line with the trend, domestic care arrangements - also against the background of the effects of demographic change - prove themselves as stable and adaptable. Meanwhile more men are integrated into care giving, and the number of neighbours and friends filling in as main caregivers has increased, too. However, the still considerable burden is noticeable. The limits of domestic care become evident any time when there are not enough caregivers available, as well as in cases of people suffering from dementia who are in need of extensive care.
Measurement of the luminosity in the ZEUS experiment at HERA II Adamczyk, L.; Andruszkow, J.; Bold, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2014, Letnik:
744
Journal Article
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The luminosity in the ZEUS detector was measured using photons from electron bremsstrahlung off protons. In 2001 the HERA collider was upgraded for operation at higher luminosity. At the same time ...the luminosity-measuring system of the ZEUS experiment was modified to tackle the expected higher photon rate and synchrotron radiation. The existing lead-scintillator calorimeter was equipped with radiation hard scintillator tiles and shielded against synchrotron radiation. In addition, a magnetic spectrometer was installed to measure the luminosity independently using photons converted in the beam-pipe exit window. The redundancy provided a reliable and robust luminosity determination with a systematic uncertainty of 1.7%. The experimental setup, the techniques used for luminosity determination and the estimate of the systematic uncertainty are reported.
The OLYMPUS Collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, R_{2γ}, a direct measure of the contribution of hard two-photon ...exchange to the elastic cross section. In the OLYMPUS measurement, 2.01 GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of ≈20° to 80°. The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved gas electron multiplier and multiwire proportional chamber detectors at 12°, as well as symmetric Møller or Bhabha calorimeters at 1.29°. A total integrated luminosity of 4.5 fb^{-1} was collected. In the extraction of R_{2γ}, radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of R_{2γ}, presented here for a wide range of virtual photon polarization 0.456<ε<0.978, are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data.
The two-photon exchange experiment at DESY Alarcon, R.; Beck, R.; Bernauer, J. C. ...
The European physical journal. A, Hadrons and nuclei,
04/2024, Letnik:
60, Številka:
4
Journal Article
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We propose a new measurement of the ratio of positron-proton to electron-proton elastic scattering at DESY. The purpose is to determine the contributions beyond single-photon exchange, which are ...essential for the Quantum Electrodynamic (QED) description of the most fundamental process in hadronic physics. By utilizing a 20 cm long liquid hydrogen target in conjunction with the extracted beam from the DESY synchrotron, we can achieve an average luminosity of
2.12
×
10
35
cm
-
2
·
s
-
1
(
≈
200
times the luminosity achieved by OLYMPUS). The proposed two-photon exchange experiment (TPEX) entails a commissioning run at a beam energy of 2 GeV, followed by measurements at 3 GeV, thereby providing new data up to
Q
2
=
4.6
(GeV/
c
)
2
(twice the range of current measurements). We present and discuss the proposed experimental setup, run plan, and expectations.
The OLYMPUS experiment used a 0.3T toroidal magnetic spectrometer to measure the momenta of outgoing charged particles. In order to accurately determine particle trajectories, knowledge of the ...magnetic field was needed throughout the spectrometer volume. For that purpose, the magnetic field was measured at over 36,000 positions using a three-dimensional Hall probe actuated by a system of translation tables. We used these field data to fit a numerical magnetic field model, which could be employed to calculate the magnetic field at any point in the spectrometer volume. Calculations with this model were computationally intensive; for analysis applications where speed was crucial, we pre-computed the magnetic field and its derivatives on an evenly spaced grid so that the field could be interpolated between grid points. We developed a spline-based interpolation scheme suitable for SIMD implementations, with a memory layout chosen to minimize space and optimize the cache behavior to quickly calculate field values. This scheme requires only one-eighth of the memory needed to store necessary coefficients compared with a previous scheme (Lekien and Marsden, 2005 1). This method was accurate for the vast majority of the spectrometer volume, though special fits and representations were needed to improve the accuracy close to the magnet coils and along the toroidal axis.
The spectrometer system for measuring ZEUS luminosity at HERA Helbich, M.; Ning, Y.; Paganis, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2006, Letnik:
565, Številka:
2
Journal Article
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The upgrade of the HERA accelerator has provided much increased collider luminosity. In turn, the improvements have necessitated a new design for the ZEUS luminosity measurements. The intense ...synchrotron radiation field, as well as the high probability of a bremsstrahlung photon in each bunch crossing, posed new experimental constraints. In this report, we describe how these challenges were met with the ZEUS luminosity spectrometer system. The design, testing and commissioning of the device are described, and the results from the initial operational experience are reported.
DESY pursues a luminosity upgrade project for the HERA electron–proton collider that foresees an increase of the luminosity by nearly a factor of 5. This is achieved mainly by a completely new layout ...of the interaction region. The new scheme involves a very early separation of the colliding beams by means of superconducting magnets that are installed inside the experimental detectors. The early beam separation allows the final focus quadrupoles to be located closer to the interaction point (IP), which in turn leads to smaller beam spot-sizes and higher luminosity.
The HERA upgrade requires the whole vacuum system in the interaction regions of the machine to be rebuilt. This amounts to about 400
m length of new electron, proton and common vacuum system. The requirements for the vacuum quality were raised in comparison to the present machine, because electrons that lost energy due to beam–gas interactions will be mainly deflected into the detector beam pipes by the superconducting separation magnets. At all possible locations we have foreseen to install NEG pumps. Another critical point is the safe handling of about 30
kW synchrotron radiation power, produced by the separation magnets in the detectors. An overview on the project is presented and some critical issues are discussed with emphasis.
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