[en] An analytical approach to determine the essential properties of a neutron polarimeter is reported, and specifically applied towards the design optimization of the High Acceptance Recoil Polarimeter. It is shown that this method allows to efficiently study and set the main characteristics of a device, and leads to a fast first-order detector layout

[en] The reaction ¹⁶O(e,e'pp) has been studied at a transferred four-momentum (ω,|q|)=(210MeV,300MeV/c) . Evidence has been obtained for direct knockout of proton pairs from the 1p shell. The excitation-energy spectrum of the residual nucleus and the missing-momentum densities indicate that knockout of a ¹S₀ pair dominates the reaction, while there is also a noticeable contribution from knockout of ³P pairs. copyright 1997 The American Physical Society

[en] The differential cross section for electron-induced neutron knockout in the reaction ⁴He(e,e^'n)³He has been measured for the first time with a statistical accuracy of 11%. The experiment was performed in quasielastic kinematics at a momentum transfer of 300 MeV/c and in the missing-momentum range of 25-70 MeV/c. The comparison of the data with theoretical calculations shows an impressive increase of the cross section resulting from final state interaction effects. Specifically, the p-n charge-exchange process dominates the cross section in this kinematical regime

[en] A Reply to the Comment by J. Jourdan, I. Sick, and J. Zhao. copyright 1997 The American Physical Society

[en] The ratio of neutron and proton yields at quasifree kinematics was measured for the reactions ²H(e,e'n) and ²H(e,e'p) at momentum transfers Q²=0.125, 0.255, 0.417, and 0.605(GeV/c)², detecting the neutron and the proton simultaneously in the same scintillator array. The neutron detection efficiency was measured in situ with the ¹H(γ,π⁺)n reaction. From this the ratio R of ²H(e,e'n) and ²H(e,e'p) cross sections was determined and used to extract the neutron magnetic form factor Gⁿ_M in a model insensitive approach, resulting in an inaccuracy between 2.1% and 3.3% in Gⁿ_M

[en] The differential cross section and the transverse-transverse interference structure function for the reaction ²H( e,e^'p)n have been determined at an np invariant mass of 2.16GeV. The data, covering a 40 degree range in the proton emission angle, indicate that Δ excitation and subsequent NΔ interaction is the dominant reaction mechanism. Calculations performed within an NΔ coupled-channel approach reproduce the cross section data, but underestimate the f_TT results by 30 to 40 percent. copyright 1997 The American Physical Society

[en] A liquid hydrogen system has been developed that serves as a scatterer for the High-Acceptance Recoil Polarimeter (HARP). In order to satisfy the conflicting design requirements regarding safety, the volume of the system, the energy loss of the recoiling protons, and the location of the cryogenic unit, a self-supporting thin-walled modular cryogenic system has been developed. The system was successfully operated during two commissioning runs of HARP in a high-luminosity electron scattering environment. The operational parameters of the system have been continuously monitored and are quantitatively understood