The PERLE Project Plan & Status

• Walid Kalib (LAL, Orsay)
• Maud Baylac (LAL, Orsay)

The development of ERLs has been recognized as one of the five main pillars of accelerators R&D in support of the European Strategy for Particle Physics (ESPP). The international panel in charge of the ERL Roadmap definition recognized PERLE project as “a central part of the roadmap for the development of energy-recovery linacs”, with milestones to be achieved by the next ESPP in 2026. The PERLE project is aiming at the construction of a novel ERL facility for the development and application of the energy recovery technique in multi-turn configuration, high current and large energy regime. It will operate in a three-turn mode, first at 250 MeV, then upgraded to 500 MeV with 20mA beam current. Such challenging parameters make PERLE a unique multi-turn ERL facility operating at an unexplored operational power regime (10MW), studying and validating a broad range of accelerator phenomena, paving the way for the future larger scale ERLs. PERLE will be the necessary demonstrator for the future HEP machine (LHeC / FCC-eh), with which it shares the same technological choices and beam parameters. Furthermore, PERLE opens a new frontier for the physics of “the electromagnetic probe”. It will be the first ERL dedicated to Nuclear Physics for studying the eN interaction with radioactive nuclei. In this seminar we will present the PERLE project status, introduce the main ongoing achievements and describe the staged strategy we will adopt toward the construction of the PERLE machine at its nominal performances.

Clinical Proton Beam Therapy: A Look into the Future

• Richard Amos (University College London)

Over the last few decades there have been significant technological advancements with the delivery of proton beam therapy (PBT). However, challenges remain with the provision of optimal and efficacious PBT to the population of cancer patients who may most benefit from this form of localized therapy. To increase accessibility of PBT to patients, delivery systems need to become smaller, cheaper, and more efficient. Furthermore, evolving techniques for treatment delivery such as proton arc therapy, ultra-high dose rate PBT, and spatially-fractionated PBT require greater versatility from delivery systems. With increasingly advanced methods of PBT clinical practice comes the need for improved accuracy for dose delivery. This seminar will briefly cover the evolution of PBT delivery from early to contemporary practice. Evolving techniques will be presented with a discussion of their implications for the technical requirements of future PBT systems. Finally, the potential application of alternative ion species for radiotherapy will be introduced.

Search for the electric dipole moment of the muon using the frozen-spin method

• Philipp Schmidt-Wellenburg (PSI, Villigen)

An electric dipole moment (EDM) of a fundamental particle would violate time and parity symmetry and by the virtue of the CPT theorem also the combined symmetry of charge conjugation and parity inversion. Searches for EDM are generally considered highly sensitive probes for new physics and might shed light on still unresolved questions in particle physics and cosmology like the origins of matter, dark matter, and dark energy. At the Paul Scherrer Institute in Switzerland, we are setting up an experiment searching for a muon EDM with a sensitivity of 3E-21 ecm using, for the first time, the frozen-spin technique in a compact storage ring. This will lay the ground work for a second phase with a final precision of better than 6e-23 ecm. This staged approach to search for a non-zero muon EDM probes previously uncharted territory and tests theories of BSM physics by: i) improving the current direct experimental limit of d < 1.5E-19 ecm (CL 90%) by roughly three orders of magnitude; ii) being a complementary search for an EDM of a bare lepton; iii) being a unique test of lepton-flavor symmetries; and iv) in the case of a null result, will be a stringent limit on an otherwise very poorly constrained Wilson coefficient.

Linacs to Narrow the Radiotherapy Gap

• Manjit Dosanjh (John Adams Institute)

By 2040, the annual global incidence of cancer is expected to rise by more than 40% from the current 19.3 million to 27.5 million cases, corresponding to approximately 16.3 million deaths. Sadly around 70% of these new cases will be in low and middle-income countries (LMICs), which lack the healthcare programmes required to effectively manage their cancer burden. While it is estimated that about half of all cancer patients would benefit from radiotherapy (RT) for treatment, there is a significant shortage of RT machines outside high-income countries. More than 15,000 electron linear accelerators (LINACs) are currently used worldwide to treat patients. However, only 10% of patients in low-income and 40% in middle-income countries who need radiotherapy have access to it. The idea to address the need for a novel medical LINAC for challenging environments was first discussed in a workshop hosted by CERN and sponsored by the International Cancer Expert Corps (ICEC), and has led to the creation of the STELLA project (Smart Technology to Extend Lives with Linear Accelerators) project. A novel, robust, modular linear accelerator that requires fewer staff and less maintenance while delivering state-of-the-art treatment is at the heart of the STELLA projects, which will also make use of artificial intelligence and deep learning to enhance the capability of the LINAC and to incorporate imaging and biological information into patient management as well as training and guiding the experts needed on the ground. For the whole project to work, the key element is a robust programme of mentorship to help train, educate and sustain on-site expertise and treatment.

Towards a High-power Cyclotron

• Huiwen Koay (TRIUMF)

The cyclotron is an important high-power driver for many frontier scientific research. It is among the most efficient yet compact accelerators that can support a broad spectrum of applications in the fields of particle physics, condensed-matter physics, astrophysics, and medical physics. The production of extremely energetic beams is becoming more realisable due to the growth of superconducting coils. Despite the increasing feasibility of a high-power cyclotron, the acceleration of a megawatt beam remains challenging, as there are many challenges. Beam loss due to various reasons, such as the significant space-charge effect during injection and the crossing of detrimental resonances are among some examples of the most important problems in current cyclotron industry. It is therefore vital to have a proper understanding of these issues from both theoretical as well as engineering aspects before further increasing the beam power. This talk covers some of these considerations, as well as giving further insights using the TRIUMF cyclotron.