The storage cell of the internal, longitudinally polarized, atomic gas target of the HERMES experiment is presented. The polarized atoms of hydrogen or deuterium are accumulated in an open-ended thin ...walled storage cell through which the circulating electron or positron beam of the HERA accelerator passes. The target areal density is
10
14
atoms/cm
2
, two orders of magnitude larger than without the cell. The construction details of the cell are described and the cell's performance during HERMES run of 1997–2000 is discussed.
A feasibility test of a new method to polarize beams of strongly interacting charged particles circulating in a storage ring is described. The stored particles, here protons, pass through a polarized ...hydrogen gas target (thickness 6times10sup 13 bold H/cmsup 2) in the ring some 10sup 10 times and become partially polarized because one spin state is attenuated faster than the other. The polarization buildup is clearly demonstrated in the present experiment.
The crystal growth of different classes of high melting multi‐component Rare Earth‐Transition Metal‐Compounds by vertical floating zone melting with inductive heating has been investigated. Phase ...diagram features of the multi‐component systems relevant for the crystallization process have been revealed. The critical zone travelling rate for RENi2B2C crystal growth is one order of magnitude smaller than for RE2TMSi3 compounds. This is attributed to different solidification modes of both classes of compounds, peritectic and congruent melting, respectively. The crystal perfection, element segregation and selected properties of the bulk crystals such as critical temperature of superconductivity were studied as function of the axis co‐ordinate. In the case of RE2TMSi2 plate‐like RESi or RESi2 precipitates were detected in the single crystalline matrix. They were partially dissolved by annealing and subsequent quenching. The anisotropy of various superconducting and magnetic properties was determined at YNi2B2C and TbNi2B2C single crystalline specimens.
The excitation spectra in the deformed nucleus 232U have been studied by means of the (p, t) reaction, using the Q3D spectrograph facility at the Munich Tandem accelerator. The angular distributions ...of tritons were measured for 162 excitations seen in the triton spectra up to 3.25 MeV. 0+ assignments are made for 13 excited states by comparison of experimental angular distributions with the calculated ones using the CHUCK3 code. Assignments up to spin 6+are made for other states.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Using X-ray powder and single crystal diffraction a new phase Y0.915Ni4.12B has been found ((191)P 6/mmm, hP113; a=14.9085(10) Å, c=6.9196(8) Å) which may be considered a defect structure of the ...YNi4B structure. X-ray powder patterns measured down to 15 K do not show any structural phase transition. The temperature dependence of the lattice parameters of Y0.915Ni4.12B was determined by Rietveld refinement. A maximum of the thermal expansion coefficients near 200 K could be observed.
Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal ...angle straight phi of the pion relative to the lepton scattering plane was formed for pi(+) electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sinstraight phi moment of the cross section is 0.022+/-0.005+/-0.003. This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a chiral-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark.
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