0000000001108789
AUTHOR
S. Caiazza
Beam-normal single spin asymmetry in elastic electron scattering off 28Si and 90Zr
We report on a new measurement of the beam-normal single spin asymmetry $A_{\mathrm{n}}$ in the elastic scattering of 570 MeV transversely polarized electrons off $^{28}$Si and $^{90}$Zr at $Q^{2}=0.04\, \mathrm{GeV}^2/c^2$. The studied kinematics allow for a comprehensive comparison with former results on $^{12}$C. No significant mass dependence of the beam-normal single spin asymmetry is observed in the mass regime from $^{12}$C to $^{90}$Zr.
Detector response of Cherenkov radiators for calorimetry in the energy range below 14 MeV
Abstract A study of the detector response of PbF 2 crystals and three different types of lead glass blocks to electrons from a 14-MeV beam of the Mainz Microtron MAMI is presented. For the first time, signal height, signal width, and homogeneity of the response of these Cherenkov radiators were determined for energies between 10 and 14 MeV. To complement the beam tests, optical properties of the materials, in particular measured transmittances in the near UV and visible spectrum, were studied. The measured detector responses were also compared to Monte Carlo simulations of energy-loss, light production, transport, and detection. These Cherenkov radiators are considered as active material o…
Electron beam studies of light collection in a scintillating counter with embedded fibers
The light collection of several fiber configurations embedded in a box-shaped plastic scintillating counter was studied by scanning with minimum ionizing electrons. The light was read out by silicon photomultipliers at both ends. The light yield produced by the 855-MeV beam of the Mainz Microtron showed a strong dependence on the transverse distance from the beam position to the fibers. The observations were modeled by attributing the collection of indirect light inside of the counter and of direct light reaching a fiber to the total light yield. The light collection with fibers was compared to that of a scintillating counter without fibers. These studies were carried out within the develop…
Operation and characterization of a windowless gas jet target in high-intensity electron beams
Abstract A cryogenic supersonic gas jet target was developed for the MAGIX experiment at the high-intensity electron accelerator MESA. It will be operated as an internal, windowless target in the energy-recovering recirculation arc of the accelerator with different target gases, e.g., hydrogen, deuterium , helium, oxygen, argon, or xenon. Detailed studies have been carried out at the existing A1 multi-spectrometer facility at the electron accelerator MAMI. This paper focuses on the developed handling procedures and diagnostic tools, and on the performance of the gas jet target under beam conditions. Considering the special features of this type of target, it proves to be well suited for a n…
Beam-normal single spin asymmetry in elastic electron scattering off Si and Zr
We report on a new measurement of the beam-normal single spin asymmetry An in the elastic scattering of 570 MeV transversely polarized electrons off $^{28}$Si and $^{90}$Zr at Q2=0.04 GeV2/c2. The studied kinematics allow for a comprehensive comparison with former results on $^{12}$C. No significant mass dependence of the beam-normal single spin asymmetry is observed in the mass regime from $^{12}$C to $^{90}$Zr.
A Time Projection Chamber with GEM-Based Readout
For the International Large Detector concept at the planned International Linear Collider, the use of time projection chambers (TPC) with micro-pattern gas detector readout as the main tracking detector is investigated. In this paper, results from a prototype TPC, placed in a 1 T solenoidal field and read out with three independent GEM-based readout modules, are reported. The TPC was exposed to a 6 GeV electron beam at the DESY II synchrotron. The efficiency for reconstructing hits, the measurement of the drift velocity, the space point resolution and the control of field inhomogeneities are presented.