Accelerator Physics
See recent articles
Showing new listings for Wednesday, 22 January 2025
- [1] arXiv:2501.10550 [pdf, html, other]
-
Title: Measurement of the mean excitation energy of liquid argonM. Strait (Fermilab)Comments: Prepared for submission to JINSTSubjects: Accelerator Physics (physics.acc-ph)
The mean excitation energy (I-value) of liquid argon is a critical input for energy estimation in neutrino oscillation experiments. It is measured to be $(205\pm4)$\,eV using the range of 402.2\,MeV protons from the Fermilab Linac. This compares to the author's recent evaluation of $(197\pm 7)$\,eV based on a combination of an oscillator strength distribution analysis, gaseous argon range measurements, sparse stopping power data on solid argon, and an extrapolation of data on the effect of phase from other substances. Using all sources of information, we recommend a value of $(203.0\pm3.2)$\,eV for liquid argon, which is significantly higher than 188\,eV, from ICRU-37's gaseous argon evaluation, commonly used in Monte Carlo codes such as \textsc{Geant4}.
- [2] arXiv:2501.10556 [pdf, html, other]
-
Title: High-Power Targetry for Muon ProductionSubjects: Accelerator Physics (physics.acc-ph); Instrumentation and Detectors (physics.ins-det)
The production of high-intensity muon beams is crucial for advancing particle and accelerator physics, both now and in the future. Achieving these high-intensity goals requires overcoming significant challenges in high-power targetry. Here, we will outline the key challenges and explore the selection of target materials, focusing on muon production and susceptibility to radiation damage -- key factors for optimal target designs.
- [3] arXiv:2501.10602 [pdf, html, other]
-
Title: Parametric mapping of the efficiency$\unicode{x2013}$instability relation in plasma-wakefield acceleratorsComments: 10 pages, 9 figuresSubjects: Accelerator Physics (physics.acc-ph)
High efficiency is essential for plasma-wakefield accelerators to be a cost-effective alternative in high-power applications, such as a linear collider. However, in a plasma-wakefield accelerator the beam-breakup instability can be seeded by a transverse offset between the driver and trailing bunch. This instability, which rapidly increases the oscillation amplitude of the trailing bunch, grows with higher power-transfer efficiency from the driver to the trailing bunch [V. Lebedev et al., Phys. Rev. Accel. Beams 21, 059901 (2018)]. In this paper, we use particle-in-cell simulations to investigate the efficiency$\unicode{x2013}$instability relation that constrains the driver-to-trailing-bunch power-transfer efficiency in beam-driven plasma accelerators. We test the relation using a grid of simulations across all parameters that affect the beam-breakup instability, assuming a uniform accelerating field (optimal beam loading) and no ion motion. We find that the previously proposed efficiency$\unicode{x2013}$instability relation represents a lower limit on the strength of the instability for a given efficiency. For each normalized wake radius, only a certain accelerating field reaches this lowest value of the transverse instability; deviating from this point can increase the growth rate by several orders of magnitude. Lastly, we highlight how the oscillation-amplitude growth of the trailing bunch can be reduced or damped with an initial uncorrelated energy spread and the presence of ion motion.
- [4] arXiv:2501.11072 [pdf, html, other]
-
Title: Proceedings of the Erice Workshop: A new baseline for the hybrid, asymmetric, linear Higgs factory HALHFBrian Foster, Erik Adli, Timothy L. Barklow, Mikael Berggren, Stewart Boogert, Jian Bin Ben Chen, Richard D'Arcy, Pierre Drobniak, Sinead Farrington, Spencer Gessner, Mark J. Hogan, Daniel Kalvik, Antoine Laudrain, Carl A. Lindstrøm, Benno List, Jenny List, Xueying Lu, Gudrid Moortgat Pick, Kristjan Põder, Andrei Seryi, Kyrre Sjobak, Maxence Thèvenet, Nicholas J. Walker, Jonathan WoodComments: 32 pages, 13 figures, 2 tablesSubjects: Accelerator Physics (physics.acc-ph); High Energy Physics - Experiment (hep-ex); Plasma Physics (physics.plasm-ph)
The HALHF collaboration has discussed a new baseline for the project, taking into account comments from the accelerator community on various aspects of the original design. In particular, these concerned the practicality of the dual-purpose linac to accelerate both colliding positron bunches and the drive beams required for the plasma linac. In addition, many other aspects of the project were also considered; the discussion and conclusions are documented in this paper. Finally, a new baseline is outlined that has been optimised and addresses several weaknesses in the original design, has higher luminosity, reduced centre-of-mass energy boost and additional features such as positron polarization as well as electron polarization. Although HALHF has become longer and more expensive, it remains significantly smaller and cheaper than other mature Higgs factory designs currently under discussion.
New submissions (showing 4 of 4 entries)
- [5] arXiv:2501.10608 (cross-list from physics.med-ph) [pdf, html, other]
-
Title: Novel Direct Alpha Spectroscopy Technique for $^{225}$Ac Radiopharmaceutical detection in Cancer CellsMahsa Farasat, Behrad Saeedi, Luke Wharton, Sidney Shapiro, Chris Vinnick, Madison Daignault, Meghan Kostashuk, Nicholas Pranjatno, Myla Weiman, Corina Andreoiu, Hua Yang, Peter KunzSubjects: Medical Physics (physics.med-ph); Nuclear Experiment (nucl-ex); Accelerator Physics (physics.acc-ph)
Targeted alpha-particle therapy (TAT) employs alpha-emitting radionuclides conjugated to tumor-targeting molecules to deliver localized radiation to cancer cells, showing great promise in treating metastatic cancers. Among these radionuclides, Actinium-225 ($^{225}$Ac, t$_{1/2}$ = 9.9 days) has emerged as a clinically promising candidate. Its decay chain generates four successive alpha emissions, resulting in highly localized and effective cytotoxic damage to cancer cells when delivered to tumor sites. However, the assumption of complete retention of $^{225}$Ac and its radioactive daughters at these target sites is often inaccurate. The nuclear recoil effect can lead to off-target distribution and unintended toxicity.
Our results revealed distinct spectral differences between radiolabeled cells and reference samples, demonstrating [$^{225}$Ac]Ac-crown-TATE uptake by AR42J cells. Detection of $^{213}$Po, one of the $^{225}$Ac decay daughters, highlighted partial retention and release of decay products from cells, providing information on intracellular retention and daughter redistribution. Geant4 simulations confirmed the alignment of experimental data with theoretical models, validating the method's accuracy. This study establishes a direct alpha spectroscopy approach for investigating $^{225}$Ac and its daughters' behavior in cells and offers a powerful tool for microdosimetry estimation.