A new CO carbonaceous chondrite from Acfer, Algeria

Many small fragments, totally weighing 118 g were found in the Acfer area by an Italian dealer. Chondrules size and types (predominance of granular olivine type), occurrence of twinned clinoenstatite and absence of plagioclase suggested a classification as CO carbonaceous chondrite

A new CK carbonaceous chondrite from Hammada Al Hamra, Libya

A single stone weighing 198 g was found in 2001 in the Hammada al Hamra region of Libya. Petrographic features (mean chondrules dimensions, coarse grained matrix and presence of AOIs and CAIs) point to a classification as CK carbonaceous chondrite

Textural and minerochemical features of NWA 1807 and 2180, two new CV3 chondrites from northwest Africa

A textural and minerochemical study has been performed on NWA 1807 and 2180 chondrites in order to determine sizes and typologies of chondrules, relative abundances of mineral phases, compositions of main phases and bulk oxygen isotope composition

Beam energy measurement at linear colliders using spin precession

Linear collider designs foresee some bends of about 5-10 mrad. The spin precession angle of one TeV electrons on 10 mrad bend is 23.2 rad and it changes proportional to the energy. Measurement of the spin direction using Compton scattering of laser light on electrons before and after the bend allows determining the beam energy with an accuracy about of 10^{-5}. In this paper the principle of the method, the procedure of the measurement and possible errors are discussed. Some remarks about importance of plasma focusing effects in the method of beam energy measurement using Moller scattering are given.Comment: 7 pages, Latex, 4 figures(.eps). In v.3 corresponds to journal publication. Talk at 26-th Advanced ICFA Beam Dynamic Workshop on Nanometre-Size Colliding Beams (Nanobeam2002), Lausanne, Switzerland, Sept 2-6, 200