Soft Report - Dipartimento di Fisica - Sapienza

FacilitiesStatic Light Scattering Laboratory – UdR RomaStatic light scattering (SLS). The source is an He-Nelaser beam with a λ=632,8 nm and a rotating harm canexplore angles between 15 and 155 degree. Thiscorrespond to a q range between 0.03-0.003 nm -1 . Apinhole and a lens with f=7.5 mm focalise the beam atthe centre of measurement cell. The scattered light iscollected trough a lens which create an imagine of thescattering volume on a multimode fibre. The intensityof scattered light is then acquired and sent to acomputer.A charge coupled device (CCD) camera has been usedto implement a low angle elastic light scattering setup.The detectable angular range covers ~2 decades, from~0.1° to ~10°. The experimental arrangement is showedin Fig.2. The light source is a 8 mW He-Ne withλ=632,8 nm -1 . The beam is spatially filtered, with asystem of pinhole-lens-pinhole, then expanded to adiameter of roughly 2.5 mm and shined onto thesample which is contained in a square glass cell 10 mmwide. The light scattered by the sample is collected bya lens L1 (F=80 mm, Φ=50 mm) and forwarded ontothe CCD camera. A second lens L2 (a standardphotographic objective Nikon macro 50mm) conjugatesthe plane of the CCD sensor and the focal plane of thel1 lens with a magnification ratio of M=Q 2/P 2 therefore,a one to one mapping between the intensity of the lightscattered at different angles and the signals out fromthe correspondin g pixel is realized. Finally, a beamstop is placed in the focal plane of the l1 lenspreventing the unscattered light from reaching thesensorCalorimetry and Rheology Laboratory – UdR RomaBeside to ancillary instrumentation, the C&R Lab is equipeed with a RheoStress RS150 Haake rheometer (max.torque = 150 mNm, min. torque = 0.5x10-4/0.2x10-4 mnM, max. speed = 1000/min, min. speed = 0.01/min) andwith a Diamond Perkin-Elmer differential scanning calorimeter (temperature range between -100 0 C and730 0 C, cooling rates between 0.01 0 C/min and 500 0 C/min.).SOFT Scientific Report 2004-0626