Contribution to a conference proceedings

GSI-2025-00401

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Slow extraction of a dual-isotope beam from SIS18

Ondreka, D. (Corresponding author)GSI* ; Bozyk, L.GSI* ; Graeff, C.GSI* ; Spiller, P.GSI* ; Stadlmann, J.GSI* ; Volz, L.GSI* ; Pilat, F. (Editor) ; Fischer, W. (Editor) ; Saethre, R. (Editor) ; Anisimov, P. (Editor) ; Andrian, I. (Editor)

2024
JACoW Publishing

Please use a persistent id in citations: doi:10.18429/JACOW-IPAC2024-TUPS29  doi:10.15120/GSI-2025-00401

Abstract: Recently, the heavy ion synchrotron SIS18 at GSI was for the first time operated with a dual-isotope beam, made up of 12C3+ and 4He+. Such a beam can be used to improve carbon radiotherapy by providing online information on dose deposition, where the helium ions serve as a probe beam traversing the patient while depositing a negligible dose. For this, the accelerator has to deliver a slowly extracted beam with a fixed fraction of helium over the spill. The difference in mass-to-charge ratio of 4He compared to 12C is small enough to permit simultaneous acceleration and to make the two isotopes practically indistinguishable for the accelerator instrumentation. Yet, it may cause a temporal shift between the two components in the spill owing to the sensitivity of slow extraction to tiny tune variations. We investigated different extraction methods, and examined the time-wise stability of the dual-isotope beam with a beam monitoring setup installed in the GSI biophysics experiment room. A constant helium fraction was obtained using transverse knock-out extraction with adjusted chromaticity.

Keyword(s): Accelerator Physics ; mc4-hadron-accelerators - MC4: Hadron Accelerators ; MC4.A16 - MC4.A16 Advanced Concepts

Note: Published by JACoW Publishing under the terms of the Creative Commons Attribution 4.0 license.

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Contributing Institute(s):

1. System Design SIS 100 / SIS 18 (SYS)

Research Program(s):

1. 621 - Accelerator Research and Development (POF4-621) (POF4-621)
2. 6G14 - GSI-MU Ion Facilities (POF4-6G14) (POF4-6G14)

Experiment(s):

1. Experiment at GSI without experiment proposal number ( - ; Facility_outside_beam_time_program )

Appears in the scientific report 2024

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