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Up to 1987 the Ruggero Caminiti's interests were mainly focussed in the field of structural analysis of ionic solutions and in developing codes in Fortran for X-RAY DATA analysis .
He started in 1975 the research activity, at Cagliari University, in collaboration with Gianni Licheri, Gabriella Pinna and Giorgio Piccaluga (the Cagliari-Group).
In 1988 he started, at Rome University, the Project of a new Energy Dispersive Diffractometer(Coworkers: Francesco Cilloco, Roberto Felici, Valerio Rossi Albertini, Claudia Sadun).
Since 1990 the research activities were mainly focussed in the field of amorphous systems and phase transitions with Valerio Rossi Albertini .
In 1999 Prof. Caminiti entered the field of biophysics. He has investigated solvent-induced conformational changes of proteins and membrane self-assembling for a couple of years before entering the emerging and fast moving field of non viral strategies for gene delivery and gene therapy.
Since 2001 Prof. Caminiti and Dr. Caracciolo have been studying the structure-activity relationship of cationic liposome/DNA complexes, the most reliable alternative to viruses as carriers of nucleic acids.
At present, the group is made of four units (listed below). The first two units perform experimental research, while the last two ones perform theoretical investigations of liquid and amorphous compounds:
1) "E.D.X.D. Laboratory" directed by Prof. Caminiti and Dr.ssa Russina (Rome SAPIENZA University)
2) "E.D.X.D. and E.D.X.R. Laboratory" directed by Dr. Rossi Albertini (I.S.M.N. - C.N.R.)
3) Unit directed by Dr. Triolo (I.S.M.N. - C.N.R.)
4) Unit directed by Dr. Carbone (Tor Vergata Università)
5) Unit directed by Dr. Gontrani (Rome SAPIENZA University)
In the EDXD Technique a continuos energy spectrum is treated simultaneously, so it must be kept in mind that every step of the data treatment involves physical quantities depend on energy:
• The intensity and polarisation of the incident beam
• The absorption coefficient of the sample
• The intensity coherently and incoherently diffracted from the sample
Eventually, the signal of the solid state detector is affected by the presence of the so called 'escape peaks' , produced by the fluorescence of the X-ray sensible crystal.
To perform an absolute measurement all the energy dependent quantities have to be measured or, at least, calculated.
Moreover, in order to obtain an accurate measurement of the static structure factor from the diffracted intensity pattern the q-range should be as wide as possible. Even if at fixed angle a considerable portion(Δk ~ 4- 5 1/Å ) of the diffraction pattern can be collected simultaneously, for an accurate structural study normally four diffraction patterns at different fixed angles must be collected and liked together to reproduce the whole diffraction spectrum.
In EDXD a continous polychromatic x-rays beam is required and the diffracted beam is energy resolved by a solid state detector kept as fixed scattering angle.
The modulus of the scattering vector q is related to the incident beam energy E and to the diffraction angle q by the relation
q =( 4π / hc ) E sin Θ , therefore the q-range of the measured spectrum depends on the choice of q and on the spectral range of the source. The q resolution is related to the energy resolution provided by the solid state detectors, tipically a few hundred eV in the hard X-ray range.