Performance of the magnetic system of a 12 MeV UPC race-track microtron

The per­for­mance of the mag­netic sys­tem of a 12 MeV elec­tron race-track mi­cro­tron (RTM) which is under con­struc­tion at the Uni­ver­si­tat Politècnica de Catalunya (UPC) is de­scribed. The RTM mag­netic sys­tem con­sists of two four-pole end mag­nets with the main field level about 0.8 T, one quadru­pole and four beam ex­trac­tion dipoles. As a source of the mag­netic field in these mag­nets a Sa-Co rare earth per­ma­nent mag­net ma­te­r­ial is used. This helps to get a quite com­pact de­sign of the RTM and al­lows to place the mag­netic sys­tems in a high vac­uum en­vi­ron­ment of the ac­cel­er­a­tor vac­uum cham­ber. We dis­cuss re­sults of nu­mer­i­cal sim­u­la­tions of the tun­ing of the end mag­nets by mean of spe­cial tuners and de­scribe their en­gi­neer­ing de­sign which per­mits to as­sem­ble the mag­nets and fix the Sa-Co blocks with­out glu­ing. Also a method and re­sults of mag­netic field dis­tri­b­u­tion mea­sure­ments and mag­net tun­ing are re­ported.Postprint (published version

Laser wire emittance measurement line at CLIC

A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical errors and of their impact on the accuracy of the emittance reconstruction are given. Laser wire systems suitable for CLIC and their main characteristics are discussed.Postprint (published version

Monte Carlo simulation of the total dose distribution around the 12 MeV UPC race-track microtron and radiation shielding calculations

The Technical University of Catalonia is building a miniature 12 MeV electron race-track microtron for medical applications. In the paper we study the leakage radiation caused by beam losses inside the accelerator head, as well as the bremsstrahlung radiation produced by the primary beam in the commissioning setting. Results of Monte Carlo simulations using the PENELOPE code are presented and two shielding schemes, global and local, are studied. The obtained shielding parameters are compared with estimates based on DIN 6847 part 2 as international recommendation of the radiation safety standards.Postprint (published version

Effect of a Temperature Mode of Radiation-thermal Sintering the Structure and Magnetic Properties of Mn-Zn-ferrites

2000NM Mn-Zn-ferrites have been produced by radiation-thermal sintering (RTS). We have studied the effect of RTS on the electromagnetic properties of ferrites. X-ray diffraction have been used to investigate general aspects of phase transformations during the radiation-thermal sintering of green compacts

Effect of a Temperature Mode of Radiation-thermal Sintering the Structure and Magnetic Properties of Mn-Zn-ferrites

2000NM Mn-Zn-ferrites have been produced by radiation-thermal sintering (RTS). We have studied the effect of RTS on the electromagnetic properties of ferrites. X-ray diffraction have been used to investigate general aspects of phase transformations during the radiation-thermal sintering of green compacts

Analysis of input coupler asymmetry influence on particle beams dynamics in accelerators with superconducting cavities

An investigation of input coupler asymmetry influence on electron beam’s dynamics in energy recovery linacs (ERL) with superconducting cavities was carried out. Were considered several types of input power couplers – coaxial and waveguide, asymmetric and symmetric. Based on numerical modeling electromagnetic fields distribution in accelerating cavity with input coupler was found, the transverse deflecting impulse was calculated.Проведено дослідження впливу асиметрії вводу потужності в надпровідні резонатори інжекційної частини прискорювача з рекуперацією енергії (ERL) на динаміку пучків електронів. Розглянуто коаксіальні і хвилеводні, асиметричні і симетричні варіанти вводу потужності. На основі чисельного моделювання знайдено розподіл електромагнітних полів у прискорювальному резонаторі з пристроєм вводу потужності, розраховано величину поперечного відхиляючого імпульсу.Проведено исследование влияния асимметрии вводов мощности в сверхпроводящие резонаторы инжекционной части ускорителя с рекуперацией энергии (ERL) на динамику пучков электронов. Рассмотрены коаксиальные и волноводные, асимметричные и симметричные варианты вводов мощности. На основе численного моделирования найдено распределение электромагнитных полей в ускоряющем резонаторе с устройством ввода мощности, рассчитана величина поперечного отклоняющего импульса

Electromagnetic fields and beam dynamics simulation for the superstructure of TESLA linear collider considering field asymmetry caused by HOM and power couplers

Some features of accelerating section field computation presented by the development of power and HOM couplers for TESLA linear collider are considered. The devices mentioned produce electromagnetic field asymmetry in the beam area, thus causing transverse kick. For this kick and its influence on beam under acceleration parameters estimation the dynamics modelling calculations were done. 3D-simulation code MAFIA was used for field computation. These data were further used in beam dynamics calculations by means of TRMTrace code. Standing wave mode was simulated while considering HOM couplers, and travelling wave in case of power couplers. Transverse kicks and focussing forces are calculated for one HOM coupler design and two coaxial FM couplers

RF and accelerating structure of 12 MeV UPC race-track microtron

We describe the design and technical characteristics of a C-band SW accelerating structure of a 12 MeV race-track microtron, which is under construction at the Technical University of Catalonia, and its RF system with a 5712 MHz magnetron as a source. Results of cold tests of the accelerating structure, before and after the brazing, and of high-power tests of the RF system at a special stand are reported. The main features of the magnetron frequency stabilization subsystem are also outlined.Postprint (published version

Thermo-fluid study of the upc race-track microtron cooling system

The cooling system of the race-track microtron (RTM), which is under construction at the Universitat Politècnica de Catalunya (UPC), has been simulated by means of a computational fluid dynamics (CFD) software. The hydraulic and thermal performance of the system for various operation conditions has been studied. Firstly, the hydraulic model has been validated by comparison with experimental measurements at different flow rates. Then, the cooling fluid temperatures and the pressure losses of the system have been determined and the capacity of the current design to remove the generated heat at nominal power has been confirmed. Finally, the maximum and average wall temperatures and heat transfer coefficients inside the accelerating structure have been calculated. These results have allowed us to localize sections of the cooling system with a low convection due to detached flows where, therefore, a risk of zones of high temperatures exists. An optimization of the cooling circuit with the aim to reduce such high temperature zones has been proposed.Postprint (published version

Current status of the 12 MeV UPC race-track microtron

A com­pact race-track mi­crotron (RTM) with the max­i­mal out­put en­er­gy 12 MeV is under con­struc­tion at the Uni­ver­si­tat Politècnica de Catalun­ya (UPC) in col­lab­o­ra­tion with the Sko­belt­syn In­sti­tute of Nu­cle­ar Physics of the Moscow State Uni­ver­si­ty, CIEMAT and a few Span­ish in­dus­tri­al com­pa­nies and med­i­cal cen­ters. The RTM end mag­nets are four-pole sys­tems with the mag­net­ic field cre­at­ed by a rare-earth per­ma­nent mag­net ma­te­ri­al. As a source of elec­trons a 3D off-ax­is elec­tron gun is used. These el­e­ments to­geth­er with a C-band ac­cel­er­at­ing struc­ture, dipole mag­nets, which allow to ex­tract the elec­tron beam with en­er­gy from 6 MeV to 12 MeV in 2 MeV step, and a fo­cus­ing quadrupole are placed in­side a vac­u­um cham­ber. We re­port on the cur­rent sta­tus of the tech­ni­cal de­sign and re­sults of tests of some of the com­po­nents.Postprint (published version