HB2023 - Table of Session: THAFP (Flash Poster Presentations WGs A-E)

Paper	Title	Page
THAFP01	Probing Transverse Impedances in the High Frequency Range at the CERN SPS	393
	E. de la Fuente, H. Bartosik, I. Mases Solé, G. Rumolo, C. Zannini CERN, Meyrin, Switzerland
	Funding: CERN The SPS transverse impedance model, which includes the major impedance contributions in the machine, can be benchmarked through measurements of the Head-Tail mode zero instability. Since the SPS works above transition energy, the head tail mode zero is unstable for negative values of chromaticity. The measured instability growth rate is proportional to the real part of the transverse impedance. Studies performed after the LHC Injectors Upgrade (LIU) showed a relevant impedance around 2 GHz with high-gamma transition optics (Q26). This paper presents the follow-up studies to probe the behavior of this beam coupling impedance contribution.
	Slides THAFP01 [2.262 MB]
	Poster THAFP01 [1.149 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP01
About •	Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP02	Resonance Extraction Research Based on China Spallation Neutron Source	397
	Y.W. An, L. Huang, Z.P. Li, S.Y. Xu, Y.S. Yuanpresenter IHEP, Beijing, People’s Republic of China
	Resonance extraction based on the RCS ring is an important aspect of beam applications. This article proposes a new design of resonance extraction based on the CSNS-RCS ring. By adjusting parameters such as the skew sextupole magnet, beam working point, RF-Kicker, etc., the simulation results from PyOrbit demonstrate the ability to rapidly extract a large number of protons within a few turns.
	Slides THAFP02 [1.497 MB]
	Poster THAFP02 [0.960 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP02
About •	Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 01 November 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP03	Measurement of Stability Diagram at IOTA at Fermilab	400
	M.K. Bossard, Y.K. Kim University of Chicago, Chicago, Illinois, USA R. Ainsworth, N. Eddy Fermilab, Batavia, Illinois, USA
	Funding: Fermilab Nonlinear focusing elements can enhance the stability of particle beams in high-energy colliders by means of Landau Damping, through the tune spread which is introduced. We propose an experiment at Fermilab’s Integrable Optics Test Accelerator (IOTA) to investigate the influence of nonlinear focusing elements on the transverse stability of the beam. In this experiment, we employ an anti-damper, an active transverse feedback system, as a controlled mechanism to induce coherent beam instability. By utilizing the anti-damper, we can examine the impact of the nonlinear focusing element on the beam’s transverse stability. The stability diagram, a tool used to determine the system’s stability, will be measured using a recently demonstrated method at the LHC. This measurement is carried out experimentally by selecting specific threshold gains and measuring them for a range of phases. The stability diagram is represented by gei¿ on the complex plane. The experiment at IOTA adds insight towards the stability diagram measurement method by supplying a reduced machine impedance, to investigate the impedance’s effect on the stability diagram, as well as a larger range of phase measurements.
	Slides THAFP03 [1.331 MB]
	Poster THAFP03 [1.692 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP03
About •	Received ※ 06 October 2023 — Revised ※ 09 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 12 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP04	Investigation of Tail-dominated Instability in the Fermilab Recycler Ring	403
	O. Mohsen, R. Ainsworth, A.V. Burov Fermilab, Batavia, Illinois, USA
	In our recent operational run, a single bunch, tail-dominated instability was observed in the Fermilab Recycler ring. This instability exclusively occurs in the vertical plane when the chromaticity is close to zero. In this study, we conduct a detailed analysis of this instability under different operational parameters. We investigate the impact of space charge on the head-tail motion and propose potential interpretations of the underlying mechanism of the instability. Moreover, we explore methods to mitigate this instability in the future.
	Slides THAFP04 [1.429 MB]
	Poster THAFP04 [0.892 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP04
About •	Received ※ 25 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 29 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP05	A Wireless Method for Beam Coupling Impedance Measurements of the LHC Goniometer	407
	C. Antuono, C. Zannini CERN, Meyrin, Switzerland M. Migliorati, A. Mostacci LNF-INFN, Frascati, Italy
	The beam coupling impedance (BCI) of an accelerator component should be ideally evaluated exciting the device with the beam itself. However, this scenario is not always attainable and alternative methods must be exploited, such as the bench measurements techniques. The stretched Wire Method (WM) is a well established technique for BCI evaluations, although nowadays its limitations are well known. In particular, the stretched wire perturbs the electromagnetic boundary conditions. Therefore, the results obtained could be inaccurate, especially below the cut-off frequency of the beam pipe in the case of cavity-like structures. To overcome these limitations, efforts are being made to investigate alternative bench measurement techniques that will not require the modification of the device under test (DUT). In this framework, a wireless method has been identified and tested for a pillbox cavity. Its potential for more complex structures, such as the LHC crystal goniometer is explored.
	Slides THAFP05 [1.088 MB]
	Poster THAFP05 [1.151 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP05
About •	Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 11 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP06	Beam Dynamics Study of a 400 kW D⁺ Linear Accelerator to Generate Fusion-Like Neutrons for Breeding Blanket Tests in Korea	411
	Y.L. Cheon, M.Y. Ahn, S. Cho, H.W. Kim KFE, Daejeon, Republic of Korea M. Chungpresenter, E. Cosgun, D. Kwak, S.H. Moon UNIST, Ulsan, Republic of Korea
	Recently, a pre-conceptual design study was conducted in Korea for developing a dedicated linear accelerator (linac) for 400 kW (40 MeV, maximum 10 mA CW) deuteron (D⁺) beams to generate fusion-like neutrons. The accelerated beam hits a solid Beryllium target to produce fusion-like neutrons, which will be utilized for technical feasibility tests of the breeding blanket including tritium production and recovery. In this work, we present a detailed start-to-end simulation and machine imperfection studies with proper beam tuning, to access the target beam availability and validate the machine specifications. We have designed the 2.45 GHz ECR ion source and a 4-vane type 176 MHz RFQ by using IBSimu, Parmteq, and Toutatis simulation codes. We propose a super-conducting linac with HWR cavities and solenoid focusing magnets to accelerate the beam up to 40 MeV. In the HEBT line, we adopt two octupole magnets and subsequent quadrupoles to make a rectangular-shaped and uniform-density beam with 20 cm x 20 cm footprint at the target. Extensive beam dynamics studies along the linac have been performed using the Tracewin simulation code. Y-L. Cheon et al., Journal of the Korean Physical Society (2023): 1-14. ** S-H. Hong et al., Fusion Engineering and Design 189 (2023): 113449.
	Slides THAFP06 [1.039 MB]
	Poster THAFP06 [1.491 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP06
About •	Received ※ 26 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP07	Preliminary Results on Transverse Phase Space Tomography at KOMAC	415
	S. Lee, J.J. Dang, D.-H. Kim, H.S. Kim, H.-J. Kwon, S.P. Yun KOMAC, KAERI, Gyeongju, Republic of Korea
	Funding: This work has been supported through KOMAC operation fund of KAERI by Ministry of Science and ICT, the Korean government (KAERI ID no. : 524320-23) Beam loss is a critical issue to be avoid in high power proton accelerators due to machine protection from radiation. Nonlinear processes add higher order moments and cause halo and tail structures to a beam, resulting in beam losses. Hence it becomes more important to characterize beams for high power accelerators. Conventional beam diagnostic methods can measure only approximate elliptical features of a beam and are not suitable for high power beams. Tomography method reconstructs a multidimensional distribution from its lower-dimensional projections. We used this method to reconstruct the 4D transverse (x, x’, y, y’) phase space distribution of the beam from the accelerator at KOMAC (Korea Multipurpose Accelerator Complex). RFQ BTS (Radio Frequency Quadrupole Beam Test System) was constructed and commissioned in 2022. In the BTS, we performed tomography experiements and obtained preliminary results on 4D transverse phase space beam distribution. We also have applied the tomography measurement techniques to the 100 MeV proton linac. In this paper, we describe the tomography measurement system and present the preliminary results obtained from the BTS and the 100 MeV proton linac.
	Slides THAFP07 [2.018 MB]
	Poster THAFP07 [1.035 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP07
About •	Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 13 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP08	Performance of the Ion Chain at the CERN Injector Complex and Transmission Studies During the 2023 Slip Stacking Commissioning	418
	M. Slupecki, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, T. Argyropoulos, H. Bartosik, P. Baudrenghien, G. Bellodi, M. Bozzolan, R. Bruce, C. Carli, J. Cenede, H. Damerau, A. Frassier, D. Gamba, G. Hagmann, A. Huschauer, V. Kain, G. Khatri, D. Küchler, A. Lasheen, K.S.B. Li, E. Mahner, G. Papotti, G. Piccinini, A. Rey, M. Schenk, R. Scrivens, A. Spierer, G. Tranquille, D. Valuch, F.M. Velotti, R. Wegner CERN, Meyrin, Switzerland E. Waagaard EPFL, Lausanne, Switzerland
	The 2023 run has been decisive for the LHC Ion Injector Complex. It demonstrated the capability of producing full trains of momentum slip stacked lead ions in the SPS. Slip stacking is a technique of interleaving particle trains, reducing the bunch spacing in SPS from 100 ns to 50 ns. It is needed to reach the total ion intensity requested by the HL-LHC project, as defined by updated common LIU/HL-LHC target beam parameters. This paper reviews the lead beam characteristics across the Ion Injector Complex, including transmission efficiencies up to the SPS extraction. It also documents the difficulties found during the commissioning and the solutions put in place.
	Slides THAFP08 [1.114 MB]
	Poster THAFP08 [1.995 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP08
About •	Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP09	Optimizing Beam Dynamics in LHC with Active Deep Learning	422
	D. Di Croce, T. Pieloni, M. Seidel EPFL, Lausanne, Switzerland M. Giovannozzi, F.F. Van der Veken CERN, Meyrin, Switzerland E. Krymova SDSC, Lausanne, Switzerland M. Seidel PSI, Villigen PSI, Switzerland
	The Dynamic Aperture (DA) is an important concept for the study of non-linear beam dynamics in a circular accelerator. It refers to the region in phase space where a particle’s motion remains bounded over a given number of turns. Understanding the features of DA is crucial for operating circular accelerators as it provides insights on non-linear beam dynamics and the phenomena affecting beam lifetime. The standard approach to calculate the DA is computationally very intensive. In our study, we aim at determining an optimal set of parameters that affect DA, like betatron tune, chromaticity, and Landau octupole strengths, using a Deep Neural Network (DNN) model. The DNN model predicts the so-called angular DA, based on simulated LHC data. To enhance its performance, we integrated the DNN model into an innovative Active Learning (AL) framework. This framework not only enables retraining and updating of the model, but also facilitates efficient data generation through smart sampling. The results demonstrate that the use of the Active Learning (AL) framework allows faster scanning of LHC ring configuration parameters without compromising the accuracy of the DA calculations.
	Slides THAFP09 [1.028 MB]
	Poster THAFP09 [6.173 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP09
About •	Received ※ 01 October 2023 — Revised ※ 04 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 31 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP10	Stripline Design of a Fast Faraday Cup for the Bunch Length Measurement at ISOLDE-ISRS	426
	S. Varnasseri, I. Bustinduypresenter, P.J. González, R. Miracoli, J.L. Muñoz ESS Bilbao, Zamudio, Spain
	In order to measure the bunch length of the beam after Multi Harmonic Buncher (MHB) of ISOLDE Superconducting Recoil Separator (ISRS) and characterize the longitudinal structure of bunches of MHB, installation of a Fast Faraday Cup (FFC) is foreseen. Several possible structures of the fast faraday cup are studied and due to timing characteristics of the beam, a microstrip design is selected as the first option. The beam is collected on the biased collector of the microstrip with a matched impedance and transferred to the RF wideband amplification system. The amplified signal then can be analyzed on the wideband oscilloscope or acquisition system to extract the bunch length and bunch timing structure with precision. The design of the microstrip FFC and primary RF measurement of the prototype are discussed in this paper.
	Slides THAFP10 [2.832 MB]
	Poster THAFP10 [0.642 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP10
About •	Received ※ 28 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 11 October 2023
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THAFP11	FPGA-Based Digital IQ Demodulator Used in the Beam Position Monitors for HIAF BRing	429
	F.F. Ni, Z.X. Li, R.X. Tian, Y. Wei, J.X. Wu IMP/CAS, Lanzhou, People’s Republic of China
	Funding: NSFC No. E911010301, Y913010GJ0, A digital beam position monitor processor has been developed for the High Intensity heavy ion Accelerator Facility (HIAF). The digital IQ demodulator is used in the Beam Position Monitor (BPM) signal processing. All data acquisition and digital signal processing algorithm routines are performed within the FPGA. In the BPM electronics system, a 250 MHz sample rates ADC was used to digitize the pick-ups signal. In the FPGA, the digital signal is filtered by ultra-narrow bandpass filters, then the digital IQ demodulator is used to calculate the beam position with difference-over-sum algorithm. The heavy ion synchrotron CSRm revolution frequency is changing from 0.2 MHz to 1.78 MHz when accelerates charged particles. In this design, a Direct Digital Synthesizer (DDS) whose output frequency changes over time is applied to generate the in-phase and quadrature components in the digital IQ demodulator. The performance of this designed BPM processor was evaluated with the online HIRFL-CSRm.
	Slides THAFP11 [1.332 MB]
	Poster THAFP11 [4.534 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP11
About •	Received ※ 28 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 19 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Probing Transverse Impedances in the High Frequency Range at the CERN SPS

393

E. de la Fuente, H. Bartosik, I. Mases Solé, G. Rumolo, C. Zannini
CERN, Meyrin, Switzerland

Funding: CERN
The SPS transverse impedance model, which includes the major impedance contributions in the machine, can be benchmarked through measurements of the Head-Tail mode zero instability. Since the SPS works above transition energy, the head tail mode zero is unstable for negative values of chromaticity. The measured instability growth rate is proportional to the real part of the transverse impedance. Studies performed after the LHC Injectors Upgrade (LIU) showed a relevant impedance around 2 GHz with high-gamma transition optics (Q26). This paper presents the follow-up studies to probe the behavior of this beam coupling impedance contribution.

Slides THAFP01 [2.262 MB]

Poster THAFP01 [1.149 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP01

About •

Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP02

Resonance Extraction Research Based on China Spallation Neutron Source

397

Y.W. An, L. Huang, Z.P. Li, S.Y. Xu, Y.S. Yuanpresenter
IHEP, Beijing, People’s Republic of China

Resonance extraction based on the RCS ring is an important aspect of beam applications. This article proposes a new design of resonance extraction based on the CSNS-RCS ring. By adjusting parameters such as the skew sextupole magnet, beam working point, RF-Kicker, etc., the simulation results from PyOrbit demonstrate the ability to rapidly extract a large number of protons within a few turns.

Slides THAFP02 [1.497 MB]

Poster THAFP02 [0.960 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP02

About •

Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 01 November 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP03

Measurement of Stability Diagram at IOTA at Fermilab

400

M.K. Bossard, Y.K. Kim
University of Chicago, Chicago, Illinois, USA
R. Ainsworth, N. Eddy
Fermilab, Batavia, Illinois, USA

Funding: Fermilab
Nonlinear focusing elements can enhance the stability of particle beams in high-energy colliders by means of Landau Damping, through the tune spread which is introduced. We propose an experiment at Fermilab’s Integrable Optics Test Accelerator (IOTA) to investigate the influence of nonlinear focusing elements on the transverse stability of the beam. In this experiment, we employ an anti-damper, an active transverse feedback system, as a controlled mechanism to induce coherent beam instability. By utilizing the anti-damper, we can examine the impact of the nonlinear focusing element on the beam’s transverse stability. The stability diagram, a tool used to determine the system’s stability, will be measured using a recently demonstrated method at the LHC. This measurement is carried out experimentally by selecting specific threshold gains and measuring them for a range of phases. The stability diagram is represented by gei¿ on the complex plane. The experiment at IOTA adds insight towards the stability diagram measurement method by supplying a reduced machine impedance, to investigate the impedance’s effect on the stability diagram, as well as a larger range of phase measurements.

Slides THAFP03 [1.331 MB]

Poster THAFP03 [1.692 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP03

About •

Received ※ 06 October 2023 — Revised ※ 09 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 12 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP04

Investigation of Tail-dominated Instability in the Fermilab Recycler Ring

403

O. Mohsen, R. Ainsworth, A.V. Burov
Fermilab, Batavia, Illinois, USA

In our recent operational run, a single bunch, tail-dominated instability was observed in the Fermilab Recycler ring. This instability exclusively occurs in the vertical plane when the chromaticity is close to zero. In this study, we conduct a detailed analysis of this instability under different operational parameters. We investigate the impact of space charge on the head-tail motion and propose potential interpretations of the underlying mechanism of the instability. Moreover, we explore methods to mitigate this instability in the future.

Slides THAFP04 [1.429 MB]

Poster THAFP04 [0.892 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP04

About •

Received ※ 25 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 29 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP05

A Wireless Method for Beam Coupling Impedance Measurements of the LHC Goniometer

407

C. Antuono, C. Zannini
CERN, Meyrin, Switzerland
M. Migliorati, A. Mostacci
LNF-INFN, Frascati, Italy

The beam coupling impedance (BCI) of an accelerator component should be ideally evaluated exciting the device with the beam itself. However, this scenario is not always attainable and alternative methods must be exploited, such as the bench measurements techniques. The stretched Wire Method (WM) is a well established technique for BCI evaluations, although nowadays its limitations are well known. In particular, the stretched wire perturbs the electromagnetic boundary conditions. Therefore, the results obtained could be inaccurate, especially below the cut-off frequency of the beam pipe in the case of cavity-like structures. To overcome these limitations, efforts are being made to investigate alternative bench measurement techniques that will not require the modification of the device under test (DUT). In this framework, a wireless method has been identified and tested for a pillbox cavity. Its potential for more complex structures, such as the LHC crystal goniometer is explored.

Slides THAFP05 [1.088 MB]

Poster THAFP05 [1.151 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP05

About •

Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 11 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP06

Beam Dynamics Study of a 400 kW D⁺ Linear Accelerator to Generate Fusion-Like Neutrons for Breeding Blanket Tests in Korea

411

Y.L. Cheon, M.Y. Ahn, S. Cho, H.W. Kim
KFE, Daejeon, Republic of Korea
M. Chungpresenter, E. Cosgun, D. Kwak, S.H. Moon
UNIST, Ulsan, Republic of Korea

Recently, a pre-conceptual design study was conducted in Korea for developing a dedicated linear accelerator (linac) for 400 kW (40 MeV, maximum 10 mA CW) deuteron (D⁺) beams to generate fusion-like neutrons*. The accelerated beam hits a solid Beryllium target to produce fusion-like neutrons, which will be utilized for technical feasibility tests of the breeding blanket including tritium production and recovery**. In this work, we present a detailed start-to-end simulation and machine imperfection studies with proper beam tuning, to access the target beam availability and validate the machine specifications. We have designed the 2.45 GHz ECR ion source and a 4-vane type 176 MHz RFQ by using IBSimu, Parmteq, and Toutatis simulation codes. We propose a super-conducting linac with HWR cavities and solenoid focusing magnets to accelerate the beam up to 40 MeV. In the HEBT line, we adopt two octupole magnets and subsequent quadrupoles to make a rectangular-shaped and uniform-density beam with 20 cm x 20 cm footprint at the target. Extensive beam dynamics studies along the linac have been performed using the Tracewin simulation code.
* Y-L. Cheon et al., Journal of the Korean Physical Society (2023): 1-14.
** S-H. Hong et al., Fusion Engineering and Design 189 (2023): 113449.

Slides THAFP06 [1.039 MB]

Poster THAFP06 [1.491 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP06

About •

Received ※ 26 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP07

Preliminary Results on Transverse Phase Space Tomography at KOMAC

415

S. Lee, J.J. Dang, D.-H. Kim, H.S. Kim, H.-J. Kwon, S.P. Yun
KOMAC, KAERI, Gyeongju, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI by Ministry of Science and ICT, the Korean government (KAERI ID no. : 524320-23)
Beam loss is a critical issue to be avoid in high power proton accelerators due to machine protection from radiation. Nonlinear processes add higher order moments and cause halo and tail structures to a beam, resulting in beam losses. Hence it becomes more important to characterize beams for high power accelerators. Conventional beam diagnostic methods can measure only approximate elliptical features of a beam and are not suitable for high power beams. Tomography method reconstructs a multidimensional distribution from its lower-dimensional projections. We used this method to reconstruct the 4D transverse (x, x’, y, y’) phase space distribution of the beam from the accelerator at KOMAC (Korea Multipurpose Accelerator Complex). RFQ BTS (Radio Frequency Quadrupole Beam Test System) was constructed and commissioned in 2022. In the BTS, we performed tomography experiements and obtained preliminary results on 4D transverse phase space beam distribution. We also have applied the tomography measurement techniques to the 100 MeV proton linac. In this paper, we describe the tomography measurement system and present the preliminary results obtained from the BTS and the 100 MeV proton linac.

Slides THAFP07 [2.018 MB]

Poster THAFP07 [1.035 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP07

About •

Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 13 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP08

Performance of the Ion Chain at the CERN Injector Complex and Transmission Studies During the 2023 Slip Stacking Commissioning

418

M. Slupecki, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, T. Argyropoulos, H. Bartosik, P. Baudrenghien, G. Bellodi, M. Bozzolan, R. Bruce, C. Carli, J. Cenede, H. Damerau, A. Frassier, D. Gamba, G. Hagmann, A. Huschauer, V. Kain, G. Khatri, D. Küchler, A. Lasheen, K.S.B. Li, E. Mahner, G. Papotti, G. Piccinini, A. Rey, M. Schenk, R. Scrivens, A. Spierer, G. Tranquille, D. Valuch, F.M. Velotti, R. Wegner
CERN, Meyrin, Switzerland
E. Waagaard
EPFL, Lausanne, Switzerland

The 2023 run has been decisive for the LHC Ion Injector Complex. It demonstrated the capability of producing full trains of momentum slip stacked lead ions in the SPS. Slip stacking is a technique of interleaving particle trains, reducing the bunch spacing in SPS from 100 ns to 50 ns. It is needed to reach the total ion intensity requested by the HL-LHC project, as defined by updated common LIU/HL-LHC target beam parameters. This paper reviews the lead beam characteristics across the Ion Injector Complex, including transmission efficiencies up to the SPS extraction. It also documents the difficulties found during the commissioning and the solutions put in place.

Slides THAFP08 [1.114 MB]

Poster THAFP08 [1.995 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP08

About •

Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAFP09

Optimizing Beam Dynamics in LHC with Active Deep Learning

422

D. Di Croce, T. Pieloni, M. Seidel
EPFL, Lausanne, Switzerland
M. Giovannozzi, F.F. Van der Veken
CERN, Meyrin, Switzerland
E. Krymova
SDSC, Lausanne, Switzerland
M. Seidel
PSI, Villigen PSI, Switzerland

The Dynamic Aperture (DA) is an important concept for the study of non-linear beam dynamics in a circular accelerator. It refers to the region in phase space where a particle’s motion remains bounded over a given number of turns. Understanding the features of DA is crucial for operating circular accelerators as it provides insights on non-linear beam dynamics and the phenomena affecting beam lifetime. The standard approach to calculate the DA is computationally very intensive. In our study, we aim at determining an optimal set of parameters that affect DA, like betatron tune, chromaticity, and Landau octupole strengths, using a Deep Neural Network (DNN) model. The DNN model predicts the so-called angular DA, based on simulated LHC data. To enhance its performance, we integrated the DNN model into an innovative Active Learning (AL) framework. This framework not only enables retraining and updating of the model, but also facilitates efficient data generation through smart sampling. The results demonstrate that the use of the Active Learning (AL) framework allows faster scanning of LHC ring configuration parameters without compromising the accuracy of the DA calculations.

Slides THAFP09 [1.028 MB]

Poster THAFP09 [6.173 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP09

About •

Received ※ 01 October 2023 — Revised ※ 04 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 31 October 2023

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THAFP10

Stripline Design of a Fast Faraday Cup for the Bunch Length Measurement at ISOLDE-ISRS

426

S. Varnasseri, I. Bustinduypresenter, P.J. González, R. Miracoli, J.L. Muñoz
ESS Bilbao, Zamudio, Spain

In order to measure the bunch length of the beam after Multi Harmonic Buncher (MHB) of ISOLDE Superconducting Recoil Separator (ISRS) and characterize the longitudinal structure of bunches of MHB, installation of a Fast Faraday Cup (FFC) is foreseen. Several possible structures of the fast faraday cup are studied and due to timing characteristics of the beam, a microstrip design is selected as the first option. The beam is collected on the biased collector of the microstrip with a matched impedance and transferred to the RF wideband amplification system. The amplified signal then can be analyzed on the wideband oscilloscope or acquisition system to extract the bunch length and bunch timing structure with precision. The design of the microstrip FFC and primary RF measurement of the prototype are discussed in this paper.

Slides THAFP10 [2.832 MB]

Poster THAFP10 [0.642 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP10

About •

Received ※ 28 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 11 October 2023

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THAFP11

FPGA-Based Digital IQ Demodulator Used in the Beam Position Monitors for HIAF BRing

429

F.F. Ni, Z.X. Li, R.X. Tian, Y. Wei, J.X. Wu
IMP/CAS, Lanzhou, People’s Republic of China

Funding: NSFC No. E911010301, Y913010GJ0,
A digital beam position monitor processor has been developed for the High Intensity heavy ion Accelerator Facility (HIAF). The digital IQ demodulator is used in the Beam Position Monitor (BPM) signal processing. All data acquisition and digital signal processing algorithm routines are performed within the FPGA. In the BPM electronics system, a 250 MHz sample rates ADC was used to digitize the pick-ups signal. In the FPGA, the digital signal is filtered by ultra-narrow bandpass filters, then the digital IQ demodulator is used to calculate the beam position with difference-over-sum algorithm. The heavy ion synchrotron CSRm revolution frequency is changing from 0.2 MHz to 1.78 MHz when accelerates charged particles. In this design, a Direct Digital Synthesizer (DDS) whose output frequency changes over time is applied to generate the in-phase and quadrature components in the digital IQ demodulator. The performance of this designed BPM processor was evaluated with the online HIRFL-CSRm.

Slides THAFP11 [1.332 MB]

Poster THAFP11 [4.534 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP11

About •

Received ※ 28 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 19 October 2023

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)