| Paper | Title | Other Keywords | Page |
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| MOP044 | A Stripline Kicker Driver for the Next Generation Light Source | kicker, high-voltage, hardware, simulation | 121 |
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Funding: DOE Contract DE-SC0004255 Diversified Technologies, Inc. (DTI), under an SBIR grant from the U.S. Department of Energy, assembled a prototype MOSFET-based pulse generator capable of meeting the original specifications for the Next Generation Light Source (NGLS) fast deflector. This pulse generator is also applicable to other high repetition-rate FELs with multiplexed beamlines. The unit must drive a 50 Ω load (such as a terminated TEM deflecting structure) at 10 kV, with flat-topped pulses at a 100 kHz average rate. The specification requires a 2 ns rise time (10 – 90%), a highly repeatable flattop with pulse width from 5 – 40 ns, and a fall time (90% to .01%) less than 1 μs (to allow a 1 MHz beam pulse rate). The driver must also effectively absorb high-order mode signals emerging from the deflector itself. The solid-state pulse generator is suitable for many accelerator systems with < 10 ns kicker requirements. The performance and applications of the unit will be described. |
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| TUP004 | Quantum FEL I: Multi-mode Theory | electron, photon, resonance, FEL | 353 |
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| The quantum regime of the FEL in a single-mode, single-particle approximation is characterized by a two-level behaviour of the center-of-mass motion of the electrons. We extend this model to include all modes of the radiation field and analyze the effect of spontaneous emission. In particular, we investigate this scattering mechanism to derive experimental conditions for realizing an FEL in the quantum regime. | |||
| TUP008 | An Analysis of Optimum Out-coupling Fraction for Maximum Output Power in Oscillator FEL | FEL, cavity, electron, laser | 368 |
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| The effect of the out-coupling fraction on the output power in oscillator FEL is analyzed. The formulas of the optimum out-coupling fraction and the corresponding maximum output power are given. They are dependent on the initial small signal gain and the passive loss rate of the light in the optical cavity. The initial comparison show that the result given by the formula agree well with the results in references. | |||
| TUP074 | High Power Coupled FEL Oscillators for the Generation of High Repetition Rate Ultrashort Mid-IR Pulses | cavity, FEL, injection, radiation | 532 |
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100-200 MeV range ERL-FELs generating few cycle short, high intensity mid-IR pulses with tens of MHz repetition rates might become attractive tools in various strong field applications. In a recent study [1] a mode locked coupled FEL oscillator scheme has been presented to produce multi-mJ level, ultra-short (<10 cycles) pulses tunable within the entire IR region. In this work an improved coupled FEL oscillator scheme is described. The coupled system operates unidirectionally (feedback in the reverse direction less than 10-8 level). The various operational regimes of the system are discussed. Some of the conclusions stated in [1] have been revised.
[1] M. Tecimer, PRST-AB 15, 020703 (2012). |
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| THP023 | Simulation of Alpha Magnet Elements in Dipole-only Tracking Codes | dipole, simulation, electron, beam-transport | 735 |
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| Alpha magnets are used in a variety of ion-beam and low-energy (< 5 MeV) electron-beam transport systems as both “switchyard” elements and as bunch compressors. A unique feature of the alpha-magnet is its natively achromatic transport. Particles of different energies, injected at a specific location and angle, will exit at the same location and (symmetry-reflected) angle but with a different time-of-flight. Despite the general usefulness of alpha magnets in low-energy beam transport and compression schemes, few simulation codes support them as native elements. The (arguably) most-common codes used for injector design, PARMELA, ASTRA and GPT (listed in order of their release) do not support alpha magnets natively, but do support modeling of space-charge-dominated beams through dipole magnets. As a result, the most commonly used injector design codes are unable to incorporate one of the most useful and interesting beam transport devices. We present a method for simulating an alpha magnet in a tracking code using dipole elements. As elegant supports both dipoles and alpha magnets, it is used to provide a basic check of the approximation and a means of estimating the induced errors. | |||
| THP056 | The SwissFEL C-band RF Pulse Compressor: Manufacturing and Proof of Precision by RF Measurements | vacuum, cavity, resonance, klystron | 859 |
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| A pulse compressor is required to compress the RF power distributed to the four accelerating structures of a single C-band (5712 GHz) module of the SwissFEL. The pulse compressor is of the barrel open cavity (BOC) type. A total of 26 BOC devices are necessary to operate the linear accelerator (26 modules or 104 C-band structures) of SwissFEL X-ray laser. The C-band BOC combines the advantages of compactness and large RF efficiency i.e. large compression factor. Key features of the BOC are described and how they have been implemented in the manufacturing and tuning processes. RF measurements of the BOC are presented to account for the mechanical precision reached by manufacturing. Up to August 2014 about 6 BOCs have been manufactured in-house and one has been high power tested in a RF test stand to simulate the operation in SwissFEL. | |||