INFN/LNL, Legnaro
PIAVE-ALPI is the INFN-LNL superconducting heavy ion linac, composed by an SRFQ (superconducting RFQ) section and three QWR sections for a total of 80 cavities installed and an equivalent voltage exceeding 70 MV. In the last years the SRFQ and the bulk niobium QWR came into routine operation, the medium energy QWR section was upgraded with a new Nb sputtered coating, ECR source was firstly improved by using water cooled plasma chamber and then replaced with a new one. The operation of the accelerator complex allowed acquiring a strong experience on many operational issues related to ECRIS, superconducting cavities and cryogenics, beam control and manipulation (with the new and higher accelerating gradient). The paper reports about operational experience, the present limitations and the future perspectives of the facility in view of the experimental campaign with the EU detector AGATA and of the use of PIAVE ALPI as RIB post-accelerator for SPES radioactive ion beam facility.
INFN/LNL, Legnaro
ITEP, Moscow
Singly charged ion sources can easily surpass the 1 kW beam power, as in TRIPS (H+, 60 mA, 80 kV, now installed at LNL) or in NIO1 (H-, 130 mA distributed into 9 beamlets, 60 kV, a project of RFX and INFN-LNL). Beam diagnostic constitutes an important instrument in the high current source development. Even if calorimetric and optical beam profile monitors become possible, still a phase space plot of the beam will be the most useful tool for validation of extraction simulation and for input of subsequent beam transport optimization. Improvements in extraction beam simulations are briefly reported, and effect of space charge neutralization is discussed. Since preliminary design of the traditional two moving slit beam emittance meter show problems with slit deformations and tolerances and with secondary emission, an Allison scanner was chosen with the advantages: only one movement is needed; data acquisition is serial and signal can have an adequate suppression of secondary electrons. The design of a compact Allison scanner head is discussed in detail, showing: 1) the parameter optimization; 2) the segmented construction of electrodes. Experimental commissioning at lower power seems advisable.