No abstract available

No abstract available

[en] Drift tube linacs with quadrupole focusing based on Interdigital H-type (IH) resonators are used at medium energies of proton beams. The linac with spatially periodic quadrupole focusing designed by V.A. Teplyakov (SH-DTL, RFQ-DTL) provides enough energy gain rate and good focusing but it is too sophisticated at tuning. The DTL with magnetic quadrupole focusing is simpler then the first one at tuning but it is deprived of advantages of RF focusing. The IH-DTL linac proposed in Frankfurt University is new perspective but rare system. The new RF quadrupole focusing structure will be proposed in this paper. Such structure consists of periodic sequence of several number of drift tubes and RF quadrupole electrodes, located in the same IH-resonator. Different designs of the structure will be considered. Electrodynamic parameters of the one convenient structure will be determined. New structure will be compared with conventional DTL, RFQ-DTL and IH-DTL linacs.

[en] One of main problems in accelerator physics is the increasing of ion beam intensity. The linear undulator accelerator with electrostatic undulator (UNDULAC-E) was proposed for ion beam acceleration. The accelerating force in UNDULAC is produced by an electric field which is a combination of two or more spatial harmonics, none of them being synchronous with the ion beam. In UNDULAC-E one of RF field space harmonic and field of electrostatic undulator are used. The value of this force is proportional to the particle charge squared. This effect allows neutralizing the beam space charge by accelerating ions with opposite charge sign within the same bunch. In this paper some results of analytical and numerical study beam space charge neutralization in UNDULAC-E using transverse electrostatic undulator are represented.

No abstract available

[en] There is a problem of low accelerating efficiency at front end part of ion linac. Conventional RFQ doesn't allow effective accelerating at energies higher than 3 MeV. The paper presents one of the possible ways to modify an RFQ for ion acceleration up to 15 MeV with reasonable energy gain rate. Conventional RFQ electrodes and modified electrodes are compared. Results of beam dynamics simulation are presented and discussed. RF design of the resonator of second section has been carried out. Main RF parameters of the resonator are presented

No abstract available

[en] Ion superconducting linac is based on periodic system from short identical niobium drift tube cavities. This linac supplies typically 1 MV of accelerating potential per cavity. By specific phasing of the RF cavities one can provide a stable particle motion in the whole accelerator. The longitudinal and transverse ion beam dynamics is studied in this linac. The equation of motion in the Hamiltonian form done by means of the smooth approximation. This equation is used for analysis of the nonlinear ion beam dynamics in superconducting linac. It was shown that the connection between the phase acceptance and the transverse emittance can be found by means of the effective potential function. The focusing methods by the solenoid field and RF field are studied. The results of this investigation are compared with the numerical simulation of ion beam dynamics in superconducting linac.

No abstract available

[en] The multi-physics design of a five cell, ${\beta }_{\mathrm{G}}=0.61$, 644 MHz superconducting elliptical cavity being developed for an energy upgrade in the Facility for Rare Isotope Beams (FRIB) is presented. The FRIB energy upgrade from 200 MeV/u to 400 MeV/u for heaviest uranium ions will increase the intensities of rare isotope beams by nearly an order of magnitude. After studying three different frequencies, 1288 MHz, 805 MHz, and 644 MHz, the 644 MHz cavity was shown to provide the highest energy gain per cavity for both uranium and protons. The FRIB upgrade will include 11 cryomodules containing 5 cavities each and installed in 80-meter available space in the tunnel. The cavity development included extensive multi-physics optimization, mechanical and engineering analysis. The development of a niobium cavity is complete and two cavities are being fabricated in industry. The detailed design of the cavity sub-systems such as fundamental power coupler and dynamic tuner are currently being pursued. In the overall design of the cavity and its sub-systems we extensively applied experience gained during the development of 650 MHz low-beta cavities at Fermi National Accelerator Laboratory (FNAL) for the Proton Improvement Plan (PIP) II.