A. Gambitta

Design of front-end components for a high-power density beamline

A prototype front end for undulator beamlines to be installed on the storage ring Elettra is presented. Design criteria are briefly discussed, in particular for those components which have to withstand heavy heat load.

A new detector for photon beam position monitoring designed for synchrotron radiation beamlines

Abstract For the latest generation of SR sources, local bump orbit feedback systems are being developed for the improvement of the stability of the delivered radiation. The high brightness beamlines using undulator radiation are the most sensitive to electron beam oscillations. Therefore, Photon Beam Position Monitors (PBPM) are being built as detectors of beam movement and as references for feedback systems. The PBPM must not be destructive and has to be suitable for continuous usage. Usual storage ring configurations permit a significant part of the radiation coming from the upstream and downstream dipoles to be superimposed with the undulator radiation. A novel detector, based on spectroscopic techniques, has been developed at ELETTRA. It can be tuned on the working energy of the undulator from a few eV to some keV. A detailed description of the detector layout and its working principle is presented. Its performance with respect to the stability requirements of the beam of synchrotron radiation is also analysed.

Elettra Present and Future Upgrades

During the last year, the third generation synchrotron light source ELETTRA could fully benefit of several upgrades that have been implemented in the frame of a project to enhance the quality of the light source. The super conducting third harmonic cavity, the feedbacks, the realignment of the whole ring and other improved devices have allowed to further, significantly optimize the beam stability and lifetime, as well as the operability and uptime of the facility. At the same time two large-scale projects are underway that will change the perspectives of the whole ELETTRA laboratory, namely the full energy booster injector and the single pass X-ray FEL FERMI@Elettra, based on the existing linac. Their status will be presented here together with the overview of the existing light source.

Heat load problems in deep X-ray lithography

Abstract A 3D mathematical model of a complete Deep X-Ray Lithography scanning unit based on the Finite Element Method (FEM) was developed to analyse the replication errors induced by the thermoelastic deformations occurring under irradiation. Different thermal and mechanical constraint conditions were considered in order to evaluate the maximum displacements of the irradiated mask area. The obtained results show that, to evaluate the replication errors, the support ring and its mechanical fittings have to be carefully considered in the model. It is observed that the absolute position error and the blur error and the error induced by the thermal expansion of the mask are both position dependent.

DESIGN OF LOW EXPANSION COMPOSITES WITH REDUCED PROCESS INDUCED UNCERTAINTIES

A procedure for the design of structural elements made of carbon-epoxy laminates with low thermal expansion in the main direction has been developed. By using an interferometric technique, the influence of material characteristics and process parameters on the thermal expansion behavior was assessed. In order to minimize the interval of uncertainty of the thermal expansion coefficient, a laminate with layers 0° and 30° coupled with layers with orientation between 45° and 60° was designed. The experimental results are in good agreement with those obtained numerically, confirming that the proposed procedure permits a low thermal expansion with high stiffness to be easily obtained.

A NEW KIND OF UHV PIEZOTRANSLATOR

A new kind of UHV compatible microdisplacement actuator has been developed. It is based on a piezoelectric translator bakable up to 150 °C, encapsulated in a stainless‐steel housing. A metal bellows allows the movement of the actuator and it gives a suitable preload to compensate the vacuum load. This new actuator has a very low outgassing rate due to the external stainless‐steel surface of the casing and to the UHV electrical feedthrough. The mechanical characteristics (resolution, load capability, stiffness) are similar to those available with standard non‐UHV compatible piezos. This new kind of microdisplacement actuator can be used in an UHV environment without any significant effect on the ultrahigh vacuum. The vacuum test and the accuracy test in UHV have been performed and will be thoroughly described.