# Advances in Particle Acceleration: Novel Techniques, Instruments and Applications
###### Abstract  
In the last decade, there have been significant advancements in accelerator technologies, driven by both fundamental research and practical applications in various fields, including X-ray science, medical treatments, and industrial processes [1]. This progress owes much to the emergence of new technologies for accelerators [2], such as new materials, including superconductors, fabrication techniques, novel acceleration methods as well as measurement and simulation tools [3]. Moreover, new technologies enable novel applications of particle accelerators that were not possible before. One of the brightest examples of the emerging accelerator technologies are the novel radiotherapy methods that have advanced over the past decade, significantly improving the precision, effectiveness, and safety of cancer treatments [4]. These innovations focus on minimizing damage to healthy tissues while delivering high doses of radiation to tumors. For example, FLASH radiotherapy is a technique that delivers a radiation dose so quickly that it spares healthy tissues while effectively damaging cancerous cells. Early studies have shown that FLASH therapy can reduce side effects and improve the therapeutic ratio [5]. However, the clinical application of FLASH therapy requires the development of accelerators with unprecedented parameters, while maintaining their commercial viability [6]. The challenges of building such accelerators include low penetration depth of electron beams and poor electron-to-photon conversion efficiency for X-ray machines. The other direction of accelerator-based radiotherapy development is the use of hadron accelerators instead of electrons or X-rays to treat cancer [7]. The key advantage is the ability to precisely control the proton beam's energy, allowing it to stop at a specific depth in the tissue (known as the Bragg peak), minimizing damage to surrounding healthy tissues. However, hadron therapy availability is currently limited due to the complexity and cost of the accelerators and other equipment. Boron Neutron Capture Therapy (BNCT) is another technique that requires hadron accelerators [8]. During BNCT, patients are first injected with a boron-containing compound that selectively accumulates in cancer cells. The tumor is then exposed to low-energy neutrons, which interact with the boron to produce high-energy alpha particles that destroy the cancer cells. Accelerator-based neutron sources have become a critical component of modern BNCT due to their advantages over traditional reactor-based neutron sources. Research and development in accelerator technologies for BNCT are ongoing, with several facilities worldwide working on improving the efficiency, cost-effectiveness, and clinical outcomes of these systems. The principle of BNCT resembles the principle of radioisotope therapy, also known as radionuclide therapy or targeted radionuclide therapy that involves the use of radioactive substances to treat various types of cancer and other medical conditions. This therapy relies on the ability of radioisotopes to deliver targeted radiation to diseased tissues, minimizing damage to the surrounding healthy tissues. Recent advancements in radioisotope therapy includes the development of theranostic isotopes used in a combined approach to both diagnose and treat diseases, particularly cancers [9]. In this approach, the same or similarisotopes are used for both imaging (diagnostic) and treatment (therapeutic) purposes. This allows for a more personalized and precise treatment strategy, as diagnostic imaging helps to identify the location and extent of the disease, while the therapeutic component targets and treats the affected areas. Advances in radioisotope therapy are enabled due to innovations in accelerator (particularly, cyclotron) technology that have improved the production and availability of medical isotopes, reducing dependence on older reactors and increasing access to newer isotopes like Ac-225, Tc-99 m, and others [10].