New experiments on crystal assisted collimation have been carried out at the CERN SPS with stored beams of 120 GeV/c protons and Pb ions. Bent silicon crystals of 2 mm long with about 170 μrad bend angle and a small residual torsion were used as primary collimators. In channeling conditions, the beam loss rate induced by inelastic interactions of particles with the crystal nuclei is minimal. The loss reduction was about 6 for protons and about 3 for Pb ions. Lower reduction value for Pb ions can be explained by their considerably larger ionization losses in the crystal. In one of the crystals, the measured fraction of the Pb ion beam halo deflected in channeling conditions was 74%, a value very close to that for protons. The intensity of the off-momentum halo leaking out from the collimation station was measured in the first high dispersion area downstream. The particle population in the shadow of the secondary collimator–absorber was considerably smaller in channeling conditions than for amorphous orientations of the crystal. The corresponding reduction was in the range of 2–5 for both protons and Pb ions

Copper phthalocyanine (CuPc) thin films have been deposited by a recently developed plasma-based method named glow-discharge-induced sublimation (GDS). The deposition of CuPc films has also been obtained by vacuum evaporation (VE) and the comparison of the two methods shows important structural differences. FT-IR and ion beam analyses (RBS-ERDA) show that the GDS-deposited films mainly consist of integer CuPc molecules, but at increasing deposition time the incorporation of damaged molecules becomes important. X-ray diffraction, FT-IR spectroscopy, and UV−vis analysis are used to study the microstructure of the CuPc films and point out that while the VE films consist of only α crystallites, a more disordered structure with the presence of both α and β polymorphs characterizes the GDS films. The latter films are also much more porous as shown by nitrogen physisorption measurements and SEM. Thermal treatments of the GDS films determine a decrease of the structural disorder at 250 °C and the complete transformation to the β polymorph at 290 °C.

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High vacuum evaporation (VE) is used for the first time to grow thin films of novel tetraphosphonate, Tiiii[H, CH 3 , Ph], and tetrathiophosphonate, TSiiii[H, CH 3 , Ph], cavitands for gas sensing applications. The sublimation rate of the compounds was monitored during the depositions and related to the final physical properties of the samples. The properties of deposited films were investigated by various techniques. FT-IR and ESI-MS indicate that the samples consist of pristine cavitand molecules and demonstrate the high purity of the VE films. AFM images show the Tiiii and TSiiii films to possess similar thickness and globular morphology. These physical analyses indicate the uniformity and homogeneity of the final samples as well as the high reproducibility of the VE technique. The sensing capabilities of the samples were investigated by exposing Tiiii- and TSiiii-coated QCMs to ethyl alcohol in very low concentrations. The sensitivity, the speed, and the detection limit of the samples were determined, indicating highly competitive sensing capabilities. Elovich kinetics and Langmuir−Henry isotherms were used to analyze the sorption process occurring onto the different samples and showed that, whereas TSiiii samples consist mainly of unspecific adsorption sites, Tiiii films show specific active sites where analyte molecules can be trapped and detected.

The UA9 experimental equipment was installed in the CERN-SPS in March '09 with the aim of investigating crystal assisted collimation in coasting mode. Its basic layout comprises silicon bent crystals acting as primary collimators mounted inside two vacuum vessels. A movable 60 cm long block of tungsten located downstream at about 90 degrees phase advance intercepts the deflected beam. Scintillators, Gas Electron Multiplier chambers and other beam loss monitors measure nuclear loss rates induced by the interaction of the beam halo in the crystal. Roman pots are installed in the path of the deflected particles and are equipped with a Medipix detector to reconstruct the transverse distribution of the impinging beam. Finally UA9 takes advantage of an LHC-collimator prototype installed close to the Roman pot to help in setting the beam conditions and to analyze the efficiency to deflect the beam. This paper describes in details the hardware installed to study the crystal collimation during 2010.-1 -arXiv:1106.5861v1 [physics.acc-ph]

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