A prototype Canadian compact accelerator-driven neutron source (PC-CANS) is proposed for installation at the University of Windsor. The source is based on a high-intensity compact proton RF accelerator that delivers an average current of 10 mA of protons at 10 MeV to the target. This study can serve as a basis for the design of an initial stage of a new high-intensity compact accelerator-driven neutron source (CANS). The accelerator consists of a short radio frequency quadrupole (RFQ), followed by an efficient drift tube linac (DTL) structure. Different variants of DTL were investigated for our studies. APF, KONUS, CH-DTL, and Alvarez DTL as normal conducting cavities with a frequency of 352.2 MHz and a superconducting cavity with a lower frequency of 176.1 MHz were considered in our Linac design. Details of the beam dynamics of the RFQ and different types of DTL are presented in this paper.

In this opening plenary talk, the speaker will discuss advances in SRF technologies are enabling PIP-II, the new proton driver for the Fermilab Accelerator Complex currently under construction. This includes advanced cavity processing methods such as nitrogen doping and the mid-T bake and innovations in cryomodule design. He will present an overview of plans to evolve Complex in the PIP-II era to take advantage of the higher power beams from PIP-II to support the LBNF/DUNE neutrino program. Finally, he will discuss a vision for the future, including a proposed extension of the PIP-II linac, and how this can eventually enable a muon collider at Fermilab.

The Los Alamos Neutron Science Center (LANSCE) accelerator complex delivers both protons (p) and negative hydrogen ions (H-) and provides various beam patterns simultaneously to multiple users. The LANSCE linac front end is still based on Cockcroft-Walton voltage generators that bring proton and H- beams to 750 keV. An upgrade of the front end to a modern, RFQ-based version is now under consideration. The most promising upgrade option is based on acceleration of two continuous beams, p and H-, injected simultaneously into a single RFQ, which has never been done before. We use an existing CST model of a proton RFQ to model simultaneous acceleration of proton and H- beams as a proof of principle for such an RFQ operation.

IFMIF-DONES (International Fusion Materials Irradiation Facility - DEMO-Oriented NEutron Source) is a facility under construction as part of the European fusion roadmap. The facility, located in Granada (Spain), is a powerful neutron irradiation facility for validation and qualification of materials to be used in fusion reactors. The construction of the facility under the framework of the DONES Programme started in March 2023, following the first DONES Steering Committee. Currently, the design is being transferred to the DONES Programme, and the first bunch of in-kind contributions are being agreed, including the ones for the construction of the 5 MW deuteron superconducting linear accelerator. The design has been consolidated during the last years through the LIPAc (Linear IFMIF Prototype Accelerator), but also to other prototypes of critical parts of the accelerator among different frameworks. These include high-power solid-state amplifiers, superconducting cavities and beam diagnostics. Most of them are already validated, while a few are still undergoing validation. In this contribution, the status of the design and manufacturing of the 5 MW linear accelerator will be reviewed, including the prototypes and validation activities being carried out under several projects.

The European Spallation Source (ESS) is a state-of-the-art research facility currently under construction in Lund, Sweden. Upon project delivery, ESS will host the most powerful linear proton accelerator and a spallation target capable of producing the brightest neutron source in the world. In order to enable safe commissioning and operation of these potent systems, each system has a dedicated personnel safety system (PSS). Together they make up the ESS PSS, an integrated system of several PSS across the facility. These systems communicate with each other through a centralised interlink system, and together determine if the facility is ready for proton beam generation in the Accelerator and consequently neutron production at the Target Station. This paper provides a summary of the inner workings, along with a discussion on the approach and proposed strategies for overcoming the identified challenges.

LANSCE accelerator complex was successfully supporting nuclear science research at LANL for more then 50 years. However, the need of the upgrade of the linear accelerator becomes immanent due to development of the modern accelerator technology, and due to inevitable aging of the existing equipment. The first stage of the planned upgrade of the linear accelerator at LANSCE includes the replacement of the outdated proton and H- Cockroft-Walton sources with the modern RFQ accelerator, and development of the new DTL. The proposed DTL is designed to accelerate protons and H- ions simultaneously, just as the existing accelerator, from 3 MeV – the output energy of the RFQ, to 100 MeV, that will allow us to keep existing Coupled Cavities Linac (CCL) intact. Presently existing megawatt-class RF power amplifiers will be used in the proposed new DTL. The details of the proposed design of the DTL will be given in the present paper. The details will include the main linear accelerator parameters, like synchrotron and betatron oscillations frequencies, as well as the developed techniques for the design studies.

Resonant cavities used in accelerating structures have been studied and used in excited modes other than the fundamental frequency TM accelerating mode. These cavities can also be overmoded to accomplish specific beam quality or bunch structures. A TE mode properly phased can be used to induce a transverse kick to an 800 MeV proton beam, such as the beam produced by the Los Alamos Neutron Science Center Side Coupled Cavity LINAC. The exited overmoded cavity as a beam kicker can be advantageous compared to a conventional parallel plate kicker, in that it can be fine-tuned by modern the RF drivers in real time. This paper presents an EM simulation for the cavity in TE mode for kicking, and the required constraints in stored energy and RF phase to generate the required deflection angle.

The Los Alamos Neutron Science Center (LANSCE) accelerator complex delivers both protons (p) and negative hydrogen ions (H-) and provides various beam patterns simultaneously to multiple users. The LANSCE linac front end is still based on Cockcroft-Walton voltage generators that bring proton and H- beams to 750 keV. An upgrade of the front end to a modern, RFQ-based version is now under consideration. The most promising upgrade option is based on acceleration of two continuous beams, p and H-, injected simultaneously into a single RFQ, which has never been done before. We use an existing CST model of a proton RFQ to model simultaneous acceleration of proton and H- beams as a proof of principle for such an RFQ operation.

The Los Alamos Neutron Science Center (LANSCE) accelerator is MW-class H-/H+ 800 MeV linear accelerator that serves five distinct user facilities that support Los Alamos National Laboratory (LANL) national security missions, commercial applications, and the Department of Energy’s Office of Science medical isotope production program. Now into it’s sixth decade of continuous operation, major accelerator systems are showing their age with decreased reliability and diminished vendor support due to equipment obsolescence. With plans to continue LANSCE operations for several more decades, LANL is exploring different avenues to modernize large portions of the accelerator. We will present the current status of those plans and an overview of supporting R&D.

The Proton Power Upgrade (PPU) Project at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory will upgrade or replace accelerator components for beam power capability from 1.4 to 2.8 MW and upgrade the first target station for 2-MW beam at 1.3 GeV and at 60 pulses per second. The remaining beam power will be available for the future second target station. PPU scope is optimized between built-in upgrade provisions from the original SNS project, cost effectiveness and technical aspects based on SNS experiences. PPU is taking a phased approach for beam power ramp-up as new equipment are installed. This paper summarizes the status of PPU project, commissioning, progresses of beam power ramp-up and operation plan in the future.

The installation of the superconducting part of the ESS Linac is progressing towards the first operation at 870 MeV on the beam dump after summer 2024. A pilot installation of 1 Spoke and 1 elliptical cryomodules was conducted in the superconducting (SCL) part of the ESS tunnel in spring 2023, to practice the installation sequence as well as to complete the cryogenic distribution system (CDS) commissioning. Currently a total of 13 spoke and 14 elliptical cryomodules (9MB + 5HB) are being installed to allow 2 MW capabilities for the first phase of the project. Overall, 30 elliptical cryomodules will be delivered to extend the energy reach to 5MW. At the time of the conference the linac will be cold and in the technical commissioning phase.

The CSNS power upgrade project (CSNS-II) has been launched. It will increase the proton beam power from 100 kW to 500 kW, along with the new construction of 9 neutron instruments. CSNS-II will utilize superconducting accelerator structures to raise the linac energy from 80 MeV to 300 MeV. The pre-research on key technologies has been completed. The newly developed RF ion source is already operational. Prototypes of the dual-spoke and 6-cell elliptical superconducting cavities and their corresponding cryomodules have been developed.

CiADS is the world’s first Accelerator Driven System under construction with a Mega-watt beam power. The linac of CiADS is designed to accelerate a 500 MeV and 5 mA proton beam with five-family superconducting resonators. The facility was lunched from mid 2021 and the hardware has finished the development of the prototype.  In this presentation, we will present the physical design of the superconducting linac, progress of key hardware and the first beam acceleration from normal conducting fronted.

The China Initiative Accelerator Driven System (CiADS), a multi-purpose facility driven by a 500 MeV superconducting RF linac, is currently under construction in Huizhou, Guangdong. In order to ensure the stable operation of the superconducting linac, we conducted optimization research on the beam quality in the front-end section of CiADS. By using the point scraping method, part of the beam halo particles are removed in advance at the entrance of the LEBT, avoiding the generation of beam halo particles. On the other hand, since the beam extracted from the ECRIS contains a portion of $H^{2+}$ and $H^{3+}$particles, impurity particles may lead to a decrease in the transmission efficiency of downstream accelerators. By separating the mixed beam, it is possible to measure the proportion and phase space distribution of the mixed beam at the exit of the ion source, thereby achieving accurate measurement of the proton beam. This paper mainly outlines the first beam commissioning of CiADS Front end. Additionally, the effectiveness of the point scraping method has been verified through transverse emittance measurement, and the proportion and phase space distribution of the mixed beam was measured. Furthermore, the stability of the ion source was tested, and the centroid shift of the ion source extracted beam was measured.

The progress and status of the high intensity short pulse 325 MHz proton linac driver for the FAIR facility in Darmstadt is described. The proton linac is designed to deliver a beam current of 70 mA at an energy of 68 MeV. The design of the normal conductiong CCH cavities was carried out in collaboration with our partners at the IAP Frankfurt and industrial partners. First bead pull measurements have been successfully performed on the CCH prototype. This prototype cavity is intended for later final production and copper plating. The construction of the ladder RFQ has been completed together with first rf measurements at levels up to 400 W. The RFQ has been delivered to FAIR and high power rf tests are expected to be performed on site during the next year. The proton driver, along with the antiproton chain of the FAIR project, has been postponed due to a re-prioritisation of the project and is now in a frozen state. All delivered components need to be brought to a state that is consistent with the project objectives. This will allow a smooth re-launch in the future. The status of this process is described in this paper.

The China Initiative Accelerator Driven System (CiADS), a multi-purpose facility driven by a 500 MeV superconducting RF linac, is currently under construction in Huizhou, Guangdong. In order to ensure the stable operation of the superconducting linac, we conducted optimization research on the beam quality in the front-end section of CiADS. By using the point scraping method, part of the beam halo particles are removed in advance at the entrance of the LEBT, avoiding the generation of beam halo particles. On the other hand, since the beam extracted from the ECRIS contains a portion of $H^{2+}$ and $H^{3+}$particles, impurity particles may lead to a decrease in the transmission efficiency of downstream accelerators. By separating the mixed beam, it is possible to measure the proportion and phase space distribution of the mixed beam at the exit of the ion source, thereby achieving accurate measurement of the proton beam. This paper mainly outlines the first beam commissioning of CiADS Front end. Additionally, the effectiveness of the point scraping method has been verified through transverse emittance measurement, and the proportion and phase space distribution of the mixed beam was measured. Furthermore, the stability of the ion source was tested, and the centroid shift of the ion source extracted beam was measured.

The accurate measurement of longitudinal beam parameters is paramount for controlling beam losses in high-power superconducting linac accelerators, particularly for low-energy beams which are significantly affected by the compensative challenges of nonlinear effects and pronounced space charge effects. In this context, systematic simulation and experimental studies of longitudinal acceptance have been performed based on the CAFe linac, employing techniques of phase and energy scanning. This paper provides a detailed description of the principles of the longitudinal acceptance measurement and presents an analysis of preliminary experimental results obtained from the CAFe linac. It was observed that the experimental longitudinal acceptance of the accelerator was reduced compared to the simulation predictions. Key factors such as transverse orbit deviations and RF phase errors are examined, and a thorough analysis of these discrepancies is discussed in the paper.

The normal conducting part of ESS LINAC in Lund (Sweden) uses 5 DTL cavities, provided by INFN LNL as in-kind partner, to accelerate 60 mA proton beam from 3.9 MeV to 90 MeV. DTL1 have been tuned, installed in the accelerator tunnel and RF conditioned in 2021, DTL2, 3 and 4 in 2022, while DTL5 has been tuned and installed in summer 2023, but not yet conditoned. All the DTLs were equiped with tuning elements like tuners and post couplers, but the challenges experienced during the tuning of the first DTL has resulted in a change of tuning strategy, which effectively reduced the timeframe to tune the other cavities from months to days. The aim of this paper is to give an overview of the the achieved results and tuning procedure performed on the DTLs.

INFN Milano - LASA recently concluded its in-kind contribution to European Spallation Source Eric, providing the 36 Superconducting Medium Beta cavities that will allow boosting the proton beam energy from 216 Mev to 571 Mev. The performances of the last four cavities, treated with Electro-Polishing as main removal step, are presented and compared with the results obtained on the remaining cavities treated with Buffered Chemical Polishing. The overall performance of the 36 cavities and lessons learned during the cavities production stages are also discussed.

The Drift Tube Linac (DTL) for the European Spallation Source (ESS ERIC) will accelerate proton beam up to 62.5mA peak current from 3.62 to 90 MeV. The 5 cavities are now fully installed and tested in the linac tunnel. Moreover, in 2023 DTL1 to DTL4 have been RF conditioned to full power and beam commissioned with max peak current at short pulses. Relevant results of these activities are presented in this paper.

An energy upgrade of the existing 100 MeV proton linear accelerator is considered at Korea Multi-purpose Accelerator Complex (KOMAC). 1 GeV proton linac for spallation neutron source is planned through 200 MeV linac upgrade as a near term project. Two options are considered for 200 MeV linac structure, one is a superconducting linac based on the half-wave resonator (HWR) and the other is a normal conducting linac based on separate drift tube linac (SDTL). In this paper, two options are presented and compared.

This talk will provide an overview of the PIP-II project, how the international contributions are being arranged, the major systems, current status, and outlook. It will also discuss how the accelerator complex will be evolved to take advantage of PIP-II beams to meet the needs of the neutrino program, including some of the accelerator physics challenges.

SNRC and CEA collaborate to the upgrade of the SARAF accelerator to 5 mA CW 40 MeV deuteron and proton beams (Phase 2). CEA is in charge of the design, construction and commissioning of the linac downstream the existing RFQ (SARAF-LINAC Project). The MEBT is now installed at SNRC and has been commissioned with both proton (cw) and deuteron (pulsed) beams. Transverse and longitudinal emittances have been measured and beam transport has been com-pared with TraceWin simulations. Cryomodules have been assembled and tested at Saclay. CM1 has been delivered to SNRC and is being integrated at SNRC. This paper presents the results of the qualification of the cryomodules at Saclay and the commissioning at Soreq.

The Proton Improvement Plan II (PIP-II) project at Fermilab is the first U.S. accelerator project that will have significant in-kind contributions (IKC) from international partners. CEA joined the international collaboration in 2018 and will deliver 10 low-beta cryomodules as IKC to the PIP-II project, with cavities supplied by INFN-LASA (Italy) and DAE-VECC (India), and power couplers and tuning systems supplied by Fermilab. An important milestone was reached in April 2023 with the Final Design Review of the cryomodule, launching the pre-production phase. This paper presents the status of the CEA activities on the construction of the LB650 pre-production cryomodule and the upgrade of the existing assembly and test infrastructures to the PIP-II requirements.

SNRC and CEA collaborate to the upgrade of the SARAF accelerator to 5 mA CW 40 MeV deuteron and proton beams (Phase 2). CEA is in charge of the design, construction and commissioning of the linac downstream the existing RFQ (SARAF-LINAC Project). The MEBT is now installed at SNRC and has been commissioned with both proton (cw) and deuteron (pulsed) beams. Transverse and longitudinal emittances have been measured and beam transport has been com-pared with TraceWin simulations. Cryomodules have been assembled and tested at Saclay. CM1 has been delivered to SNRC and is being integrated at SNRC. This paper presents the results of the qualification of the cryomodules at Saclay and the commissioning at Soreq.

The Proton Power Upgrade (PPU) project at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) has completed the installation and testing of all project scope required to meet threshold key performance parameters (KPPs), supported beam commissioning in June 2024, and transitioned to operations in July 2024. Increasing the beam energy from 1.0 to 1.3 GeV required the installation of seven additional cryomodules in the SNS Linac along with supporting RF systems. The accumulator ring injection and extraction regions were upgraded, a 2 MW mercury target was developed, and ancillary target systems were upgraded to support high-flow gas injection, mercury off-gas treatment, and ortho-para fraction control in the cryogenic moderator hydrogen loop. Three of four threshold KPPs have been demonstrated, and the project is planning for its final review in early 2025. Beam power on the first target station (FTS) will be ramped up to 2 MW over the next two years. Completion of the PPU project supports increased scientific capability at the FTS and will support operation of the second target station (STS) upon its completion. Lessons learned will be documented and a project closeout report will be written prior to the final closeout of the project.

A prototype Canadian compact accelerator-driven neutron source (PC-CANS) is proposed for installation at the University of Windsor. The source is based on a high-intensity compact proton RF accelerator that delivers an average current of 10 mA of protons at 10 MeV to the target. This study can serve as a basis for the design of an initial stage of a new high-intensity compact accelerator-driven neutron source (CANS). The accelerator consists of a short radio frequency quadrupole (RFQ), followed by an efficient drift tube linac (DTL) structure. Different variants of DTL were investigated for our studies. APF, KONUS, CH-DTL, and Alvarez DTL as normal conducting cavities with a frequency of 352.2 MHz and a superconducting cavity with a lower frequency of 176.1 MHz were considered in our Linac design. Details of the beam dynamics of the RFQ and different types of DTL are presented in this paper.