hippi june20051

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PROGRESS IN CH-DTL DEVELOPMENT AND BEAM DYNAMICS DESIGN AT THE IAP- FRANKFURT UNIVERSITY Gianluigi Clemente Institut für Angewandte Physik J.W. Goethe-Universität, Frankfurt am Main, Germany HIPPI WP2 YEARLY Meeting CERN, June 3rd 2005

TOPIC: 

TOPIC Introduction to the CH- DTL The FAIR Project and its new Proton Injector Main Features Beam Dynamics Investigation The Development of the CH Normal Conducting Mechanical Development Time Schedule Conclusion People

THE H-MODE Family: 

THE H-MODE Family The CH-DTL operates in the H21(0) Model and it, at beam energies between 5 MeV/u and 150 MeV/u, shows a large potential as well for room temperature as for superconducting designs. At the moment IAP, ANL and FNAL* are developing CH Cavities * Ostroumov and Al. “Front end design of a MultiGev H Linac”. PAC 05 Proceedings. To be published

THE FAIR PROJECT: 

THE FAIR PROJECT Basic Parameters for the CH Proton Injector The FAIR Project (Facility for Antiprotons and Ions Research) at GSI needs a dedicated proton injector for the synchrotron SIS in order to increase the proton intensity of the existing UNILAC/SIS12 combination by a factor of 70, resulting in 7 1012 protons in the synchrotron. Estimated cost:~ 10 M€; Commissioning: 2009

The KONUS beam dynamics: 

The KONUS beam dynamics Respect to the standard Alvarez Structure the Shunt Impedance of the H-Mode linacs can be significantly improved by reducing the drift tubes capacity and rising the resonance frequency: slim drift tubes without any focusing elements allow, at the same time, to achieve a higher accelerating field gradient (~ 6 MeV/meter) and to choose a higher resonance frequency. The lack of transversal focusing element can be supplied by the use of the KONUS Beam Dynamics

Beams investigations: 

Beams investigations Beam dynamics is performed starting from an RFQ output distribution at 3 MeV, 95.7 mA released by the IAP-RFQ group lead by Prof. Schemmp. Respect to previous results the matching section between the RFQ and the CH has been updated consisting now of a single quadruple, space to host beam diagnostics (phase probes, current transformers, etc) and a triplet that leads the beam into the first CH Tank

FAIR: Beams investigations: 

FAIR: Beams investigations FINAL LAYOUT FOR THE CH PROTON INJECTOR PROPOSED FOR THE GSI-FAIR.

FAIR: Beam Investigation: 

FAIR: Beam Investigation 100 % Beam Envelopes and RMS Emittance Growth (normalised)

CH: Mechanical Development: 

CH: Mechanical Development The mechanical development is focused on 3 major problems Insertion of the drift tube inside the stems General mechanical stability and resistance Optimisation of the single cell geometry taking into account also the needed space for the cooling system A cold model consisting of 8 equidistant gaps (β / 2 = 45 mm) is, at moment, under construction in order to test the fabrication steps and find out technical solutions for the assembly of the prototype cavity. The main idea is to weld the stainless steel stems into the yoke from outside and to avoid any screws into the cavity; massive copper half drift tubes will be press-fit into the stems and its expected to achieve excellent RF contacts and mechanical precision with this technique. A complete new ends cell concept has been developed both to host quadruple lens or diagnostics devices and to tune the ends cell of the cavity.

The Drift tubes insertion: 

The Drift tubes insertion Mechanical Simulation performed with the ANSYS CODE has shown how press-fitting will ensure good quality of the contacts: the half tube will be cooled down and then inserted into the stem. The following thermal dilatation will spread the mechanical tension exactly all around the contacts: this technique is expected to ensure both good RF contacts and mechanical stability

END CELLS CONCEPT: 

END CELLS CONCEPT To increase the voltage in the ends cell and achieve good flatness of the electric field one possible way is to increase the magnetic inductance at the cavity’s extremes: in the IH Cavity, for instance, this can be obtained by large undercuts in the base girder In the proton injector no girder is foreseen and the tuning can be achieved by enlarging the final nose: this drift space can be used to host the quadruple lens or some beam diagnostics device such us phase probes.

END CELLS CONCEPT: 

END CELLS CONCEPT The result will be a very compact structure with each tank fed by its own generator and directly connected with the following one reducing considerably the overall length of the machine. The linac will be mounted on rails and the intertank flanges could be easily open to perform any kind of maintenance

End Cells Concept: 

End Cells Concept Microwave Studio Simulations of our model have confirmed how this technique can improve the distribution of the electric fields inside the cavity: final adjustments can be obtained by changing the DRIFT/LENGTH period.

TUNING: 

TUNING EFFECT OF THE VARIATION OF THE G/L RATIO IN THE SECOND GAP. Estimated Effective Shunt Impedance ~ 100 M/m

WORK IN PROGRESS: 

WORK IN PROGRESS A fabrication model is, at present under construction at the IAP: it will be used to check all the fabrications steps (i.e. welding and its effect on the stems alignments) as well as for vacuum tests and preliminary RF Measurements: according to the experience gained with this model the first CH Prototype will be built within end of ’06. Channel for the water cooling

IAP-WP2: Status at June ‘05: 

IAP-WP2: Status at June ‘05 The cold model design has been completed and its fabrication is in progress in the IAP mechanical workshop This model will be used to gain experience on the realisation of the new CH-DTL Cavity: within the end of this year vacuum and RF Measurements will be performed on this model. Beam dynamics is continuously developing also according to the FAIR requirements: new simulations with an initial doublet will be performed in the next future. Concerning the HIPPI Project a complete report will be written within this month according to the time schedule of the WP2. Concerning the building of the real prototype it seems feasible to complete it within December 2006.

People: 

People U.Ratzinger (IAP, HEAD SECTION) H.Podlech (IAP, LINAC AG Leader) R.Tiede (IAP, HIPPY WP2 and 5 Responsible) G.Clemente (IAP, PhD Student) S.Minaev (ITEP, IAP GUEST) K. Dermati (GSI Technical Office)

…and Final: 

…and Final GRAZIE DANKE MERCY THANK YOU