An Accelerator Physics Experiment (APEX) was conducted in the Relativistic Heavy Ion Collider (RHIC) to verify the formation, rotation, and size of resonance islands.The experiment provides lattice parameters to be used to facilitate an alternative method of transition crossing in the Hadron Storage Ring (HSR) of the Electron Ion Collider (EIC) project by producing a non-adiabatic kick to the off-axis beam within the island to displace the beam to the central closed orbit across transition. Proton beam was injected directly into an octupolar field driven stable resonance island in RHIC. This paper describes the procedures used to perform this Resonance Island Injection (RII) and discusses the experimental results.

In recent years, proton and heavy-ion therapy has become increasingly widespread in clinical applications, and has emerged as one of the important means for cancer treatment. The commonly used particle types for this therapy are protons and carbon ions. However, further research into the biological effect has found that helium ions have both high biological effectiveness and small penumbra characteristics, which enable more precise locate of the tumor while also effectively killing tumor cells. And the highest energy of the helium ions used in therapy is 235MeV/u. Therefore, the equipment size and cost required for helium ions therapy will be significantly less than that for carbon ions therapy. To this end, this paper proposes a design for a helium-ion therapy synchrotron that also possesses the capability for proton therapy. The design employs eight ultra-high field dipole magnets to achieve a compact envelope function. Additionally, the design incorporates both multi-turn painting injection and mismatched injection methods in two directions, significantly minimizing the use of bump magnets. This results in a highly compact accelerator structure.

The PS Booster is the first synchrotron in the CERN proton accelerator complex, which delivers both high-brightness and high-intensity beams. Injection to the Booster is at a kinetic energy of 160 MeV, therefore space charge is a main limiting factors for beam quality. Maximising the longitudinal emittance and adding a second, and sometimes third, RF harmonic are measures to decrease the line density and so reduce the effect of space charge. Nonetheless, beam loss and transverse emittance growth are still unavoidable at low energy. Recent studies have been focused on the possibility of adapting the magnetic cycle to further reduce the impact of space charge. With a faster ramp, the time spent in a high space charge regime is reduced but the available RF voltage limits the bucket area. Alternatively, with a slower acceleration the RF bucket area and longitudinal emittance can be increased, which will reduce the magnitude of the space charge detuning, but more time will be spent at low energy. This contribution explores the effects of different magnetic cycles on the beam and the possibility of further optimising the booster acceleration.

The CERN Super Proton Synchrotron (SPS) Radio Frequency (RF) system was upgraded as part of the Large Hadron Collider Injector Upgrade (LIU) project, and now comprises six 200 MHz travelling wave structures, each fed by a separate RF power amplifier. While the upgrade was targeting the peak power for capture and acceleration of the beams for the High Luminosity LHC, it also brought an increase in the available average power for fixed-target beams. The additional power introduced margins which were first probed and exploited in 2024, when the SPS RF system had to be operated at majorly reduced power, during failures that blocked a single power amplifier or accelerating structure. Specific examples from the 2024 run are given, together with the mitigation measures. This contribution summarizes the efforts and results, highlighting in particular the improvements needed for the control of the RF voltage for easier switching to the degraded mode of operation and back, as well as the impact of the impedance of an undriven cavity.

To prepare the Super Proton Synchrotron (SPS) as an injector for the High Luminosity Large Hadron Collider (HL-LHC), its Radiofrequency (RF) system was majorly upgraded. The 200 MHz travelling wave structures were rearranged, adding two solid-state power amplifiers and a new Low-Level RF (LLRF) system. The increase in RF power and reduction of the beam coupling impedance at the fundamental frequency were designed for capture and acceleration of four trains of 72 bunches spaced by 25 ns at an intensity of 2.3e11 protons per bunch with bunch lengths of 1.65 ns ±10% at SPS extraction. These beam parameters have first been demonstrated in 2024 after careful optimisation of all the main longitudinal settings: voltage program at fundamental and higher harmonics, interplay of one turn-delay feedback, feedforward and longitudinal damper, as well as controlled emittance blow-up. This contribution details the achieved beam parameters and the conditions that allowed them, along with the encountered limitations.

J-PARC MR delivers 30 GeV proton beams to the neutrino facility and the hadron experimental facility, and an upgrade plan is underway to increase beam power by shortening the MR cycle time and increasing the number of particles per bunch. As a result, the beam power for neutrino experiments has achieved its original design value of 750 kW in 2023 and reached 800 kW in 2024. The target beam power of this upgrade plan is 1.3 MW for the Hyper-Kamiokande experiment.The current RF system consists of 9 fundamental cavities and 2 second harmonic cavities for a total of 11 RF systems, but it is necessary to add two more fundamental cavities to further shorten the MR cycle time. Preparations are underway to begin operation of the 10th RF system in 2025 and the 11th in 2027. In addition, as the number of particles increases, further beam loading compensation will be required, so we are also working on upgrading the RF source. We present the progress of the MR RF system upgrade.

In the slow extraction operation of the J-PARC Main Ring (MR), ensuring the uniformity of the extracted beam's time structure (“spill structure”) is crucial. One primary factor distorting the spill structure is the random fluctuation of the horizontal tune caused by current ripples in the main magnet power supplies. To address this issue, a system called the "tune ripple canceller" has been developed. This system calculates correction values for the horizontal betatron tune based on current ripples and controls the spill structure using fast-responding quadrupole magnets. In 2021, proof-of-principle beam experiments demonstrated its effectiveness in improving the spill structure. Subsequently, as part of the MR's power upgrade plan, the main magnet power supply system was upgraded by 2022. During this upgrade, the current measurement system was reconfigured, and the power spectrum of the current ripples was altered. As a result, it is now urgent to update the hardware and software of the tune ripple canceller system to align with these changes. This paper highlights updates, addresses challenges, and explores strategies to further enhance spill structure control in the MR.

Considered the current Nuclotron structure for precision EDM-experiments as an independent synchrotron storage ring equipped with electrostatic deflectors. In this regard, the design must ensure the preservation and precise regulation of spin dynamics stability. Moreover, the initial purpose of the structure as a booster of polarized beams in the collider has been preserved.

To study the electric dipole moment of light nuclei, it is necessary to maintain the direction of the spin along the particle's motion along the ring. The first obvious solution to this problem is to use elements with an electric field that rotates the spin in the direction opposite to the spin rotation in a magnetic field. The most successful solution in this case is the Wien filter, which ensures spin rotation while maintaining the co-direction of the spin and momentum. In this case, the ring structure consists of arcs with bending magnets and straight sections on which Wien filters with crossed electric and magnetic fields are installed. The paper considers various versions of a magneto-optical structure that implements the "Quasi-frozen" spin method for studying the electric dipole moment of deuterons and protons. This approach can be used in developing an upgraded Nuclotron structure.