Title:

"Report from the 23rd International Conference on Cyclotron and their Applications"

Abstract:

The 23rd international conference on cyclotrons and their applications (CYC2022) took place as a virtual conference in Beijing, P. R. China on December 5-9, 2022, hosted by the China Institute of Atomic Energy (CIAE) and Huazhong University of Science and Technology (HUST).

Title:

"The LightHouse Accelerator for Tc Production"

Abstract: 

Lighthouse – A superconducting electron accelerator for the industrial production of the medical isotope Mo-99

G. Blokesch, M. Grewe, B. Keune, J.M. Krämer, V. Kümper, M. Pekeler, C. Piel, C. Quitmann, T.T. Trinh, P. vom Stein, et al.
RI Research Instruments GmbH, Friedrich-Ebert-Str. 75, 51429 Bergisch Gladbach, Germany

Medical isotopes are used for diagnostics and cure of tens of millions of patients worldwide every year. For the largest parts they are produced in fission reactors from enriched Uranium-235 leaving behind long-lived nuclear waste. Around the world organizations are therefore working to make medical isotope production more sustainable.
RI Research Instruments was commissioned by the Institute for Radioelements (IRE, Belgium) with the design of a superconducting electron linac (75MeV, 40mA, CW) for the industrial production of Mo-99.
The short development time and high requirements on availability (23h/d, ca. 360d/y) lead to the use of proven concepts from the Cornell CBETA accelerator and a redundant design with two DC photoguns able to produce the initial electron beam.
I report on the innovative aspects of this design. They include two injectors for full redundancy in the source, a merger feeding e-beam from either of the injectors into the linac, a beam splitter dividing the beam 50/50 for illuminating the target from opposite sides, beam dynamics for low-loss beam transport, and a machine protection system able to switch the beam off in <1µs.

The project was stopped by the customer IRE at the end of 2022 due to technical challenges with cooling the target. Reflecting on physics, technology and project execution I suggest lessons learnt for large accelerator projects.

Literature:
LightHouse - A Superconducting LINAC for Producing Medical Isotopes
Proc. of LINAC2022, Liverpool, UK, 28 August-02 September 2022
https://jacow.org/linac2022/papers/mopojo04.pdf

Title:

"Collective Effects from CDR to TDR - Experiences from the Diamond-II Project"

Abstract: 

An upgrade is planned of the Diamond Light Source storage ring to increase the brightness of the beamlines by reducing the emittance and increasing the energy of the electron beam. As part of the design process, current-dependent effects have been studied to ensure that the user requirements are fulfilled and that the machine can be operated stably at high current. This includes many effects such as intra beam scattering, single- and multibunch instabilities, fill patterns, transient beam loading and ion instabilities. This talk describes the experience of studying collective effects for both the Conceptual and Technical Design Report for the Diamond-II project. The process, organization and resource requirements will be discussed in addition to lessons learned.

Title:

"A new beam-cavity interaction calculation model and its application to harmonic cavity studies for Hefei Advanced Light Facility"

Abstract:

In order to cope with the intrabeam scattering effect induced emittance growth, the Touschek scattering effect induced beam lifetime limitation and the beam-impedance coupling effect induced instability growth, harmonic cavities are generally used to stretch the bunch in longitudinal direction and provide Landau Damping. It has become a necessary choice for modern advanced synchrotron light sources. However, harmonic cavities for bunch lengthening can cause some adverse effects, such as beam loading, Robinson instability, etc.，which possibly limit bunch lengthening. It is not trivial to study them, and an efficient tool is generally required. This report will introduce a new beam-cavity interaction calculation model, and two calculation codes developed based on this model. Both of them can be efficiently used for bunch lengthening study in arbitrary filling mode. Some important results related to bunch lengthening for Hefei Advanced Light Facility (HALF) with the presence of passive harmonic cavities will also be presented in this report.

Title:

"Investigations of TRIBs in BESSY III lattices"

Abstract:

At BESSY II and the MLS, the transverse resonance island buckets (TRIBs) special operation mode allows the simultaneous operation of two well-separated orbits when a third-order resonance condition is satisfied. One of the applications of this mode is the fast switching of the helicity of circularly polarized light. In this talk, we present some investigations of the possibility of implementing TRIBs in the context of BESSY III lattice design, which may open new possibilities and applications for advanced light sources. 

Title:

"Injection with a Non-linear Kicker at BESSY II"

Abstract:

Top-up operation at BESSY II is performed with high injection efficiencies of more than 95 %. However, the four-kicker bump and the half-sine-wave septum pulser, that form the present injection system, both contribute to an injection distortion of the stored beam with an amplitude of a few millimeters for several thousand turns. A non-linear pulsed injection kicker (NLK) could be used to reduce the kicker induced distortion by a factor of approximately 30 and thus create a necessary condition for transparent injection. Studies with a NLK and optimized sextupole settings have shown that it is also possible to achieve injection efficiencies of up to 97 %. With regards to the application of the NLK for BESSY II user operation and a possible injection method for BESSY III, the NLK was investigated in more detail. In this talk we will give an overview of the present investigations and results.

Title:

''An introduction to the Science and Technology of Compact High Field Superconducting Cyclotrons''

Abstract: 

Superconducting cyclotrons are now entering their 5th decade of operations. At first intended mainly for Nuclear Physics, with heavy ions having charge mass ratios of 1/2 or less, there has been steady progress in beam physics and superconducting magnet technologies, such that proton acceleration, with much more severe focusing and isochronism requirements, is now possible in the same compact, high field regime. This has allowed for important applications in medicine- first radiotherapy, where superconducting cyclotrons dominate new installs, and now diagnostic and therapeutic isotope production with proton beams as well, in astonishingly compact systems. We will review where we are now with this class of cyclotrons, how we got here, and what developments will likely take place in the coming years.

Title:

"Depth profile camera"

Abstract:

The cyclotron at HZB provides a 68 MeV proton beam for therapy as well as for experiments. By using a novel camera setup, the range of the proton beam is measured optically. The setup consists of a phantom with a luminescent layer inside and a CMOS camera. By measuring the emission of the luminescent layer, the Bragg peak and the range of the proton beam can be visualized for different energies. A dedicated LabVIEW code provides various evaluation possibilities: the Bragg curve and the lateral beam profile are generated and displayed. The system is sensitive to energy differences of less than 400 keV. The results were obtained with a beam intensity of less than 10 pA/cm² homogenous proton beam in front of the degrader. The measurement is done in real time and provides live feedback on changes such as beam energy and beam size.

Title:

"A New Center for Heavy Ion Research in the US"

Abstract: 

Progress in cancer therapy with ions heavier than protons, i.e., helium, carbon, oxygen and even neon, requires research and development capability. Ion research activity, however, is limited from the absence of U.S. accelerator facilities offering ion beams for therapy – placing the U.S. significantly behind Europe and Asia. With dramatic advances in beam delivery and compact accelerators, the potential exists to create a facility that can play a leadership role in particle therapy and ion-based research. This seminar will cover summary details of a new center for ion therapy research in Waco, TX, under development and in collaboration with recognized accelerator entities both academic and industrial along with medical partnerships. The advanced accelerator technologies will produce CW, variable-energy beams for both clinical and research applications, offering a complete range of ions, intensities and energies required by the medical community, including the capability to perform ultra-high dose irradiation (FLASH) research.

Title:

"Non-linear beam dynamics with Python: Code development status and application outlooks for Bessy"

Abstract: 

Non-linear beam dynamics appear in many scenarios in accelerator physics. Applications range from multi-turn extraction, emittance exchange by crossing resonances, BESSY2 TRIBs mode operation and even beam lifetime calculations from dynamic aperture models utilizing Nekhoroshev estimates.

Regarding the design of BESSY III it is in particular important to examine in detail the influence of the placement of elements in the lattice on the phase space distortion (which are related to the so-called resonance driving terms), preferably along the entire lattice.

There are a few available codes which can compute driving terms, but they tend to be notoriously difficult to maintain/extend due to their age. On the other hand, from a theoretical point of view, so-called Lie-map methods provide an elegant description of the underlying physics. To the author's knowledge, a code to manage and handle chains of Lie-operators directly in an object-oriented way does not yet exist.

Due to the broad acceptance of Python as an elegant and easy-to-learn programming language, three projects in the form of Python modules have been initiated, with the goal to complement existing accelerator codes by providing a broad range of analysis tools and functionality. In this presentation we shall give an overview of these projects, their scope, current limits and future development plans.

 

Title:

"Accelerator Physics and Lattice Strategy of a Steady-State Micro-Bunching Light Source"

Abstract: 

A novel accelerator light source mechanism called Steady-State Micro-Bunching (SSMB) is being actively studied. The idea of SSMB is to scale the longitudinal focusing of an electron beam in a storage ring from the conventional radio frequency range to optical laser wavelengths, with a motivation to provide high-average-power narrow-band radiation. In this talk, I will give a sketch of the SSMB accelerator physics research ongoing in Tsinghua University. Three lattice scenarios extensively investigated by us, from longitudinal weak focusing to longitudinal strong focusing, to generalized longitudinal strong focusing, will be presented with some of the key beam physics behind emphasized.

Title:

"SPEED: Worldwide first implementation of the EEHG seeding scheme at a storage ring"

Abstract: 

At DELTA, the 1.5-GeV synchrotron radiation source operated by TU Dortmund University, multiple techniques are used to generate ultrashort pulses based on laser-electron interactions. One example is the CHG (coherent harmonic generation) scheme. Here, the interaction of electron bunches with laser pulses in a first undulator (modulator) causes a periodic electron energy modulation. A chicane then induces a density modulation, which gives rise to coherent emission of ultrashort pulses at harmonics of the seed laser wavelength in a second undulator (radiator). Recently, another seeding scheme was demonstrated at DELTA. A reconfiguration of the electromagnetic U250 device that incorporated the two undulators and the chicane went underway in summer 2022 to demonstrate EEHG (echo-enabled harmonic generation) to enable the generation of higher harmonics. The coils of the U250 were rewired to create two modulators for a twofold laser-electron interaction, two chicanes for the manipulation of the electron density, and a radiator, with only a few undulator periods comprising each section. The commissioning process of the worldwide first implementation of EEHG in a single straight section of a storage ring and first measurements are presented.

Title:

 

Abstract: