ALBA, a 3rd generation synchrotron light source in Barcelona, Spain, is currently preparing its upgrade to the 4th generation low emittance machine ALBA II. As part of this upgrade, an active normal conducting harmonic RF system will be installed to improve beam lifetime. However, discountinuities in the filling pattern, such as ion clearing gaps, induce RF cavity voltage variations along the revolution period. This effect, known as transient beam loading (TBL), severely degrades the bunch lengthening performance of the double RF system. In this contribution, we present a semianalytical study of the TBL effect in ALBA II as a function of gap size, together with a mitigation strategy. The results show that, by modulating the power delivered to the main and harmonic RF cavities at the revolution frequency, the impact of TBL can be effectively mitigated, limiting the degradation of the bunch lengthening performance to 2–18% for gap lengths ranging from 2–11%.

ALBA is a 3rd generation synchrotron light source and is member of the RF2.0 project, which aims to reduce the carbon footprint of this kind of large research facilities by improving its efficiency, reliability and operational sustainability. In this contribution, we present the work done together with our partner COMMTIA, that has developed the Adaptive Power and Digital Control (APDC) for a 5 kW 1.5 GHz SSPA amplifier, which enables a real-time efficiency optimization by changing dynamically the drain voltage of the transistors while delivering RF power. This is done in two different ways: either the SSPA sets the desired voltage as function of the output power or the Digital Low Level RF system sets the voltage to the SSPA by means of a digital signal. This maximizes the efficiency at each point of operation, ensuring stable performance under the varying load and thermal environments common on accelerator facilities. The laboratory measurements indicate substantial improvements in efficiency, that comes with the cost of the SSPA linearity gain reduction. These developments show how flexible solid-state RF systems can satisfy demanding high-performance requirements while lowering the energy consumption and carbon footprint of accelerator infrastructures.

Within the Research Facility 2.0 (RF2.0)* project, one of the objectives is the development of novel permanent-magnet technologies and refurbishment strategies aimed at reducing energy consumption in accelerator facilities. In this context, ALBA, ELYTT, and HZB are jointly developing a tunable quadrupole prototype based on permanent magnets, conceived as a demonstrator for next-generation, energy-efficient magnet systems. The prototype is designed to achieve high-gradient focusing while drastically reducing power consumption relative to conventional electromagnets, eliminating the need for large coils and water cooling. Its compact architecture also eases integration into densely packed storage-ring lattices. Tunability is provided through a hybrid approach combining movable soft-iron elements and small auxiliary coils, offering a wide operational range with minimal energy demand. This contribution presents the electromagnetic and mechanical design of the prototype, the assembly strategy, and the current status of the manufacturing and testing.

ALBA is upgrading its storage ring into a 4th-generation diffraction-limited facility, which demands redesigned vacuum chambers. Most of the 268.8 m ring, divided into 16 arcs, will use OFHC-Cu or CuCrZr to dissipate synchrotron radiation and minimize resistive-wall impedance. To meet the injection-efficiency re-quirements, former 16 mm circular cross-section has been replaced by a rhombic geometry providing a 22 mm hori-zontal aperture, 1.25 mm wall thickness and clearances of 1 mm to the magnet poles. Its structural response shows 13 MPa maximum stress with deformations of 3 µm. A short bellows is foreseen between each pair of BPM blocks to absorb chamber displacements from alignment tolerances and thermal expansions while keeping BPM positions fixed. At dipole positions, antechambers with crotch absorbers manage the radiation heat load, with each arc receiving 20.5 kW of power. The entire ring will be NEG-coated to accelerate conditioning and reach the required pressure of 1×10⁻⁹ mbar at 100 Ah. This contri-bution presents the vacuum system status and the design, fabrication progress of the prototypes.

The Double Dipole Kicker (DDK) topology has been designed to perform off-axis injection into the ALBA II storage ring, currently under design. The DDK creates a multipole magnetic field by summing two opposite dipo-lar fields generated by four inner and four outer conduc-tor rods. The two dipolar fields are powered by two inde-pendent pulsed power supplies that deliver identical pulses of up to 3 kA and 1.75 s. The rods are precisely positioned along in-air ceramic grooves, to maximize the kick of the injected beam coming from the booster syn-chrotron and, to minimize the field at the stored beam position during top-up injections. A pure dipolar mode is also available when the inner rods are not powered, which it will be used during ALBA II commissioning. The in-vacuum ceramic chamber is coated with a titani-um layer of a variable thickness with the aim of minimiz-ing the effect of induced eddy currents on the stored beam. A DDK prototype has been built and installed alongside the four kickers that generate the injection bump at the ALBA storage ring. First injection tests with the DDK are presented.

The Productive Research Environment (PRE) session at IPAC’25 explored practices and challenges in fostering sustainable and motivating research environments in the accelerator community. A preliminary survey of 51 managers and leaders revealed high levels of motivation during the early career stage, but also highlighted concerns regarding staffing shortages, budgetary constraints, and the long-term career prospects of young researchers.　Session presentations addressed career experiences, sustainable institutional models, and survey-based perspectives across different career stages. The subsequent panel discussion engaged additional senior leaders and covered key themes including human resources and diversity, leadership development, mentorship and supervision, and intergenerational collaboration. The session concluded that clear goals, adequate resources, inclusive cultures, structured leadership and mentoring, and effective knowledge transfer are essential for productive research environments. Despite current limitations, the strong motivation of young researchers offers a promising foundation. Building on this, PRE aims to expand its surveys and sustain dialogue at future IPAC meetings to strengthen human resource capacity and foster diversity across the global accelerator community.These findings and perspectives will be reported and further discussed at the conference.

A 5BA lattice with an emittance of 200 pm*rad at 3 GeV and a circumference of 268.8 m is under design for ALBA-II. The injection is performed off-axis in a straight section only 4.7 m long with a single non-linear kicker needing a horizontal dynamic aperture larger than 6 mm. An optics of the injection section with asymmetric waists of the beta functions, low horizontal beta at the septum location and high beta at the kicker, has proved to perform better than a high beta section. This arrangement in the injection sections allows tuning equal phase advances and chromatic functions in all the cells and recover a pseudo 16-fold symmetric ring both on- and off-energy. The robustness of this solution in presence of errors has improved the injection efficiency with errors from 90% to 100%, keeping the dynamic aperture larger than 7 mm and the same Touschek lifetime longer than 6 hours. The magnetic design along with the performances of the lattice with errors and the injection process are presented in this paper.

ALBA is working on the upgrade project that shall transform the actual storage ring, in operation since 2012, into a 4th generation light source, in which the soft X-rays part of the spectrum shall be diffraction limited. The project was launched in 2021 with an R&D budget to build prototypes of the more critical components. The storage ring upgrade is based on a MBA lattice which has to comply with several constraints imposed by the decision of maintaining the same circumference (269m), the same number of cells (16), the same beam energy (3GeV), and as many of the source points as possible unperturbed. At present, the lattice optimization, iterating with the technical constraints of space and performance, is ongoing. This paper presents the situation of the project, with the present proposed lattice and equipment design; the status of the prototyping of magnets, pulsed elements. vacuum chambers, buttons BPMs, and girders; the proposed RF system with fundamental and harmonics cavities; and the general context of the upgrade.

ALBA Synchrotron Light Source will be upgraded into a diffraction limited machine by the replacement of the storage ring, which implies the reduction of the emittance by at least a factor of twenty. Compactness ratio of the magnetic elements has increased by a factor of 2. The new lattice has been designed with two big constrains. Firstly, keeping the same orbit length allows us to preserve the actual injector. Secondly, the medium and short straights will be collinear with respect to ALBA current layout to avoid moving the present Insertion Devices Beamlines. The bending magnet beamlines must be repositioned on the new machine. Magnetic array, vacuum chambers and girders are positioned with respect to the main orbit under tight clearances, that’s why envelope studies of those clearances will have to be performed for the 3 subsystems. Easiness of assembling and installation of the different subsystems of the machine has to be considered also as a design requirement, in order to minimize the installation time. A mock-up of one sector is being prepared for this reason. The upgrade will be executed before the end of the decade and will be profiting at maximum all existing ALBA infrastructures, in particular the building.