WG2010
KEK, Ibaraki, Japan
JAEA, Ibaraki-ken, Japan
WG2022
KEK, Ibaraki, Japan
JAEA, Ibaraki-ken, Japan
Kyungpook National University, Daegu, Republic of Korea
| Paper | Title | Page |
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WG2010 |
Strategy of the Lattice and Optics Design of 2 loop Compact ERL and Multi-GeV ERL | |
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| Multi-GeV class energy recovery linac (ERL) is considered as a successor of X-ray light source, Photon Factory. As an optional light source, XFEL-O is planned to be operated by utilizing the ERL loop as a recirculating linac to accelerate an electron beam twice. In both ERL and XFEL-O projects, the extreme low emittance is necessary to achieve the high performance. Therefore, an emittance growth induced by space charge (SC) effects and coherent synchrotron radiation (CSR) wake is the critical issue in an optics design. The SC effects are remarkable in non-relativistic energy region such as an injector and after energy recovering. CSR wake affect an electron bunch in the bending magnets. To evaluate the beam quality including the effects, we utilize the 6D tracking codes, General Particle Tracer (GPT) and 'elegant'. The codes are switched at the reasonable electron energy: it is named self-consistent start-to-end simulation (S2E). The S2E simulation has been demonstrated for the 200 MeV class Compact ERL (cERL) with a double loop circulation. We report the strategy of lattice design and S2E simulation for the multi-GeV ERL as well as cERL. | ||
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Slides WG2010 [2.290 MB] | |
WG2022 |
Envelope Matching from Injector to Main Linac for ERL | |
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| Since the brilliance of electron beams in Energy Recovery Linac (ERL) is primarily determined by the performance of its injector, the improvement of the injector performance is essential issue. After the injector, the electron beams are accelerated by a main linac to relativistic energy region, in which an emittance growth due to space charge force can be ignored. Because an injected beam with lower energy and a returned beam with higher energy pass through the same main linac, the beam optics in the main linac is restricted to design a reasonable optics throughout the return loop. Therefore, minimization of the emittance, and matching of beam optics to that of the return loop have to be carried out during the injector optimization. The injector parameters have been optimized using multi-objective method with genetic algorithm and a particle tracking code GPT. However, the optimized emittance was far larger than a target emittance, so that some conflict between the minimization of emittance and the restriction of beam optics have been found in the optimization. We report the optimization results, and the strategy to avoid the conflict and to produce a reasonable beam performance. | ||
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Slides WG2022 [2.786 MB] | |