Design and Test of a Klystron Intra-Pulse Phase Feedback System for Electron Linear Accelerators
<p>The state of the art for measured phase stability in pulsed RF plants worldwide is compared with the facilities at LNF-INFN. The solid fill color represents the best results published or disseminated by other laboratories, while the transparent fill color accounts for the spread between the worst- and best-case scenarios when multiple plants are available.</p> "> Figure 2
<p>SPARC_LAB klystron n.2 (K2) RF system. Highlighted block diagram of the fast intra-pulse feedback that includes the solid state driver amplifier (D2) and the Binary Phase Shift Keying (BPSK), which realizes the phase jump for the pulse compressor that feeds the two accelerating sections (S1 and S2). Moreover, a screenshot of its control system with the typical phase detector and error amplifier output signals is reported at the bottom.</p> "> Figure 3
<p>Recent measurement at SPARC_LAB of the S-band fast intra-pulse feedback capability with Libera LLRF front-end. The klystron phase measured with feedback off is shown in blue, whereas that with feedback on is shown in orange. There are approximatively 200 shots at 10 Hz repetition rate. A jitter reduction down to <math display="inline"><semantics> <mrow> <mn>0.046</mn> </mrow> </semantics></math> deg <span class="html-small-caps">rms</span> has been obtained, with an overall compression of a factor > 4.</p> "> Figure 4
<p>New error amplifier board (<b>left</b>) and the new RF chassis (<b>right</b>) realized at INFN-LNF laboratories for the klystron loop upgrade.</p> "> Figure 5
<p>(<b>a</b>) Block diagram of the laboratory experimental setup for the klystron loop bench test, and (<b>b</b>) oscilloscope capture of the functionality of the slow feedback. The error amplifier output without slow feedback is shown in orange; the same output with slow feedback in operation is shown in blue. It can be clearly seen that the loop also allows us to reach a phase value close to the desired one when the RF pulse is off. This minimizes the transient and the overall phase modulation required to reach the steady state, as shown in the waveform zoom.</p> "> Figure 6
<p>Intra-pulse feedback prototype measurement results at SPARC_LAB facility on the C-band power plant. In bold the results obtained with the new feedback on.</p> ">
Abstract
:1. Introduction
2. First Feedback Implementation at SPARC_LAB
2.1. SPARC_LAB Facility
SPARC_LAB RF System
2.2. First Feedback Design and Implementation
3. Intra-Pulse Phase Feedback Upgrade
4. Preliminary Measurement Results
5. Discussion and Future Research Direction
6. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
- Pompili, R.; Anania, M.; Bellaveglia, M.; Biagioni, A.; Castorina, G.; Chiadroni, E.; Cianchi, A.; Croia, M.; Di Giovenale, D.; Ferrario, M.; et al. Femtosecond timing-jitter between photo-cathode laser and ultra-short electron bunches by means of hybrid compression. New J. Phys. 2016, 18, 083033. [Google Scholar] [CrossRef]
- Giannetti, G.; Anania, M.; Bellaveglia, M.; Chiadroni, E.; Cianchi, A.; Del Dotto, A.; Galletti, M.; Gallo, A.; Giribono, A.; Piersanti, L.; et al. Experimental and numerical characterization of timing jitter for short electron beams in a linear photo-injector. Meas. Sci. Technol. 2023, 35, 025015. [Google Scholar] [CrossRef]
- Fabris, A.; Delgiusto, P.; Pribaz, F.; Sodomaco, N.; Umer, R.; Veljak, L. Experience and Developments on the S-band RF Power System of the FERMI Linac. In Proceedings of the 6th International Particle Accelerator Conference, Richmond, VA, USA, 3–8 May 2015; p. WEPMA042. [Google Scholar] [CrossRef]
- Kim, C.; Park, S.J.; Min, C.K.; Hu, J.; Kim, S.H.; do Joo, Y.; Heo, H.; Kim, D.E.; Lee, S.; Kang, H.S.; et al. Review of technical achievements in PAL-XFEL. AAPPS Bull. 2022, 32, 15. [Google Scholar] [CrossRef]
- Geng, Z.; Alex, J.; Arsov, V.; Craievich, P.; Gough, C.; Kalt, R.; Lippuner, T.; Löhl, F.; Pedrozzi, M.; Prat, E.; et al. RF Jitter and Electron Beam Stability in the SwissFEL Linac. In Proceedings of the FEL’19; Number 39 in Free Electron Laser Conference; JACoW Publishing: Geneva, Switzerland, 2019; pp. 400–403. [Google Scholar] [CrossRef]
- Decker, F.J.; Krasnykh, A.; Morris, B.; Nguyen, M. A stability of LCLS linac modulators. In Proceedings of the 2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC), San Diego, CA, USA, 3–7 June 2012; pp. 695–699. [Google Scholar] [CrossRef]
- Inagaki, T.; Konno, C.; Maesaka, H.; Ohshima, T.; Otake, Y.; Sakurai, T.; Shirasawa, K.; Shintake, T. High-gradient C -band linac for a compact x-ray free-electron laser facility. Phys. Rev. Spec. Top.-Accel. Beams 2014, 17, 080702. [Google Scholar] [CrossRef]
- Reukauff, M. A Low-Noise Front-End for an X-Band Particle Deflector at DESY. Ph.D. Dissertation, Technische Universität Hamburg, Hamburg, Germany, 2022. [Google Scholar] [CrossRef]
- Fabris, A.; Byrd, J.; D’Auria, G.; Doolittle, L.; Gelmetti, F.; Huang, G.; Jones, J.; Milloch, M.; Predonzani, M.; Ratti, A.; et al. The LLRF System for the S-Band RF Plants of the FERMI Linac. IEEE Trans. Nucl. Sci. 2016, 63, 861–868. [Google Scholar] [CrossRef]
- Ferrario, M.; Alesini, D.; Anania, M.; Artioli, M.; Bacci, A.; Bartocci, S.; Bedogni, R.; Bellaveglia, M.; Biagioni, A.; Bisesto, F.; et al. EuPRAXIA@SPARC_LAB Design study towards a compact FEL facility at LNF. Nucl. Instrum. Methods Phys. Res. Sect. Accel. Spectrometers Detect. Assoc. Equip. 2018, 909, 134–138. [Google Scholar] [CrossRef]
- Ferrario, M.; Alesini, D.; Anania, M.; Bacci, A.; Bellaveglia, M.; Bogdanov, O.; Boni, R.; Castellano, M.; Chiadroni, E.; Cianchi, A.; et al. SPARC_LAB present and future. Nucl. Instrum. Methods Phys. Res. Sect. B Beam Interact. Mater. Atoms 2013, 309, 183–188. [Google Scholar] [CrossRef]
- Pompili, R.; Alesini, D.; Anania, M.P.; Arjmand, S.; Behtouei, M.; Bellaveglia, M.; Biagioni, A.; Buonomo, B.; Cardelli, F.; Carpanese, M.; et al. Free-electron lasing with compact beam-driven plasma wakefield accelerator. Nature 2022, 605, 659–662. [Google Scholar] [CrossRef] [PubMed]
- Sabbatini, L.; Alesini, D.; Anania, M.; Bellaveglia, M.; Biagioni, A.; Buonomo, B.; Cantarella, S.; Cardelli, F.; Chiadroni, E.; Costa, G.; et al. Sabina: A research infrastructure at lnf. In Proceedings of the 12th International Particle Accelerator Conference (IPAC’21), Campinas, Brazil, 24–28 May 2021. [Google Scholar] [CrossRef]
- Yang, Y.; Byrd, J.; Fystro, G.; Meyer, D.; Nassiri, A.; Pietryla, A.; Smith, T.; Sun, Y.; Baricevic, B. Digital LLRF System Development and Implementation at the APS Linac. In Proceedings of the 31st Linear Accelerator Conference (LINAC22), Liverpool, UK, 28 August–2 September 2022. [Google Scholar] [CrossRef]
Signal: Klystron 3 FWD | Jitter (deg) | Jitter (fs) |
---|---|---|
klystron loop OFF | 0.065 | 31.6 |
klystron loop ON | 0.019 | 9.2 |
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Piersanti, L.; Bellaveglia, M.; Cardelli, F.; Gallo, A.; Magnanimi, R.; Quaglia, S.; Scampati, M.; Scarselletta, G.; Serenellini, B.; Tocci, S. Design and Test of a Klystron Intra-Pulse Phase Feedback System for Electron Linear Accelerators. Photonics 2024, 11, 413. https://doi.org/10.3390/photonics11050413
Piersanti L, Bellaveglia M, Cardelli F, Gallo A, Magnanimi R, Quaglia S, Scampati M, Scarselletta G, Serenellini B, Tocci S. Design and Test of a Klystron Intra-Pulse Phase Feedback System for Electron Linear Accelerators. Photonics. 2024; 11(5):413. https://doi.org/10.3390/photonics11050413
Chicago/Turabian StylePiersanti, Luca, Marco Bellaveglia, Fabio Cardelli, Alessandro Gallo, Riccardo Magnanimi, Sergio Quaglia, Michele Scampati, Giorgio Scarselletta, Beatrice Serenellini, and Simone Tocci. 2024. "Design and Test of a Klystron Intra-Pulse Phase Feedback System for Electron Linear Accelerators" Photonics 11, no. 5: 413. https://doi.org/10.3390/photonics11050413