A high power liquid hydrogen target for the Mainz A4 parity violation experiment

Abstract

We present a new powerful liquid hydrogen target developed for the precise study of parity violating electron scattering on hydrogen and deuterium. This target has been designed to have minimal target density fluctuations under the heat load of a 20$\mu$A CW 854.3 MeV electron beam without rastering the electron beam. The target cell has a wide aperture for scattered electrons and is axially symmetric around the beam axis. The construction is optimized to intensify heat exchange by a transverse turbulent mixing in the hydrogen stream, which is directed along the electron beam. The target is constructed as a closed loop circulating system cooled by a helium refrigerator. It is operated by a tangential mechanical pump with an optional natural convection mode. The cooling system supports up to 250 watts of the beam heating removal. Deeply subcooled liquid hydrogen is used for keeping the in-beam temperature below the boiling point. The target density fluctuations are found to be at the level 10${}^{-3}$ at a beam current of 20 $\mu$A.

arXiv comment24 pages, 14 figures, submitted to NIM A

References in corpus (11)

• Precision Measurement of the Weak Mixing Angle in Moller Scattering
• Measurement of Strange Quark Contributions to the Nucleon's Form Factors at Q^2=0.230 (GeV/c)^2
• The Strange Quark Contribution to the Proton's Magnetic Moment
• Parity-violating electroweak asymmetry in $\vec{e}p$ scattering
• Evidence for Strange Quark Contributions to the Nucleon's Form Factors at $Q^2$ = 0.108 (GeV/c)${}^2$
• Observation of Parity Nonconservation in Moller Scattering
• Measurement of the Transverse Beam Spin Asymmetry in Elastic Electron Proton Scattering and the Inelastic Contribution to the Imaginary Part of the Two-Photon Exchange Amplitude
• Measurements and simulations of Cherenkov light in lead fluoride crystals
• A High Power Hydrogen Target for Parity Violation Experiments
• The Cryogenic Target for the G${}^0$ Experiment at Jefferson Lab
• A luminosity monitor for the A4 parity violation experiment at MAMI

Cited by in corpus (6)

• Measurement of Strange Quark Contributions to the Vector Form Factors of the Proton at Q**2=0.22 (GeV/c)**2
• The P2 Experiment - A future high-precision measurement of the electroweak mixing angle at low momentum transfer
• A luminosity monitor for the A4 parity violation experiment at MAMI
• Study of Two-Photon Exchange via the Beam Transverse Single Spin Asymmetry in Electron-Proton Elastic Scattering at Forward Angles over a Wide Energy Range
• Charged lepton induced one kaon production off the nucleon
• The Qweak High Performance LH2 Target