NAPAC2022 - List of Keywords (booster)

Paper	Title	Other Keywords	Page
TUZD1	The Electron-Positron Future Circular Collider (FCC-ee)	collider, operation, luminosity, electron	315
	F. Zimmermann, M. Benedikt CERN, Meyrin, Switzerland K. Oide DPNC, Genève, Switzerland T.O. Raubenheimer SLAC, Menlo Park, California, USA
	Funding: Work supported by the European Union’s H2020 Framework Programme under grant agreement no.~951754 (FCCIS). The Future Circular electron-positron Collider (FCC-ee) is aimed at studying the Z and W bosons, the Higgs, and top quark with extremely high luminosity and good energy efficiency. Responding to a request from the 2020 Update of the European Strategy for Particle Physics, in 2021 the CERN Council has launched the FCC Feasibility Study to examine the detailed implementation of such a collider. This FCC Feasibility Study will be completed by the end of 2025 and its results be presented to the next Update of the European Strategy for Particle Physics expected in 2026/27.
	Slides TUZD1 [10.072 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUZD1
About •	Received ※ 03 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 21 August 2022 — Issue date ※ 02 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA18	Promise and Challenges of a Method for 5x5 Sigma Matrix Measurement in a Transport Line	quadrupole, extraction, emittance, simulation	382
	M. Borland, V. Sajaev, K.P. Wootton ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source (APS) is upgrading the storage ring to a design that requires on-axis injection. Matching between the incoming beam and the ring is important to ensure high injection efficiency. Toward this end, we have developed and tested a method for measuring all σ matrix elements except those related to the time coordinate. We report on challenges inherent in this technique, based on simulation and real-world trials.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA18
About •	Received ※ 29 July 2022 — Accepted ※ 05 August 2022 — Issue date ※ 29 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA22	Measurements of Bunch Length in the Advanced Photon Source Booster Synchrotron	synchrotron, detector, background, photon	394
	J.C. Dooling, W. Berg, J.R. Calvey, K.C. Harkay, K.P. Wootton ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357. A bunch duration monitor (BDM) was installed at the end of a synchrotron light monitor (SLM) port in the Advanced Photon Source (APS) booster synchrotron. The BDM is based on a fast Hamamatsu metal-semiconductor-metal detector with nominal rise and fall times of 30 ps. Bunch length data is especially important as the bunch charge will be raised from 3 nC, used in the existing machine, to as much as 18 nC for APS-Upgrade operation. During preliminary high-charge studies, the SLM image is observed to move over a period of minutes while the BDM signal intensity varies; the motion is likely due to thermal loading of the in-tunnel synchrotron light mirror. Work is underway to stabilize the position using a simple feedback system and motorized mirror mount, as well as a new synchrotron light mirror assembly with improved thermal load handling. The feedback system will maintain optical alignment on the BDM at an optimum position based on the SLM centroid location. The optical layout and feedback system will be presented along with preliminary bunch length data.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA22
About •	Received ※ 04 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 09 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA23	First Beam Results Using the 10-kW Harmonic Rf Solid-State Amplifier for the APS Particle Accumulator Ring	injection, photon, rf-amplifier, linac	398
	K.C. Harkay, T.G. Berenc, J.R. Calvey, J.C. Dooling, H. Shang, T.L. Smith, Y. Sun, U. Wienands ANL, Lemont, Illinois, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source (APS) particle accumulator ring (PAR) was designed to accumulate linac pulses into a single bunch using a fundamental radio frequency (rf) system, and longitudinally compress the beam using a harmonic rf system prior to injection into the booster. The APS Upgrade injectors will need to supply full-current bunch replacement with high single-bunch charge for swap-out injection in the new storage ring. Significant bunch lengthening is observed in the PAR at high charge, which negatively affects beam capture in the booster. Predictions showed that the bunch length could be compressed to better match the booster acceptance using a combination of higher beam energy and higher harmonic gap voltage. A new 10-kW harmonic rf solid-state amplifier (SSA) was installed in 2021 to raise the gap voltage and improve bunch compression. The SSA has been operating reliably. Initial results show that the charge-dependent bunch lengthening in PAR with higher gap voltage agrees qualitatively with predictions. A tool was written to automate bunch length data acquisition. Future plans to increase the beam energy, which makes the SSA more effective, will also be summarized.
	Poster TUPA23 [2.477 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA23
About •	Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 07 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA38	Sublinear Intensity Response of Cerium-Doped Yttrium Aluminium Garnet Screen with Charge	electron, FEL, linac, storage-ring	437
	K.P. Wootton, A.H. Lumpkin ANL, Lemont, Illinois, USA
	Funding: This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Swap-out injection to the Advanced Photon Source Upgrade storage ring necessitates the injection of ~17 nC electron bunches at 6 GeV. To aid with machine tune-up and to measure the beam size, diagnostic imaging screens are envisaged at several locations in the beam transport line from the booster synchrotron to the storage ring. As such, it is important to determine whether the response of these screens to charge is linear. In the present work, we examine the effect of sublinear intensity quenching of a Cerium-doped Yttrium-Aluminium-Garnet scintillator screen. A 1.3 megapixel FLIR BlackFly monochrome digital camera was used to image the beam at the scintillator. At 7 GeV beam energy, over the charge densities investigated (<10 fC um^-2), an approximately 10 % reduction of the imaging intensity due to quenching of the scintillator was observed.
	Poster TUPA38 [0.557 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA38
About •	Received ※ 02 August 2022 — Accepted ※ 03 August 2022 — Issue date ※ 09 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXD6	Electron Cloud Measurements in Fermilab Booster	electron, simulation, proton, laser	556
	S.A.K. Wijethunga, J.S. Eldred, E. Pozdeyev, C.-Y. Tan Fermilab, Batavia, Illinois, USA
	Fermilab Booster synchrotron requires an intensity upgrade from 4.5×10¹² to 6.5×10¹² protons per pulse as a part of Fermilab’s Proton Improvement Plan-II (PIP-II). One of the factors which may limit the high-intensity performance is the fast transverse instabilities caused by electron cloud effects. According to the experience in the Recycler, the electron cloud gradually builds up over multiple turns in the combined function magnets and can reach final intensities orders of magnitude greater than in a pure dipole. Since the Booster synchrotron also incorporates combined function magnets, it is important to discover any existence of an electron cloud. And if it does, its effects on the PIP-II era Booster and whether mitigating techniques are required. As the first step, the presence or absence of the electron cloud was investigated using a gap technique. This paper presents experimental details and observations of the bunch-by-bunch tune shifts of beams with various bunch train structures at low and high intensities and simulation results conducted using PyECLOUD software.
	Slides WEXD6 [4.483 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEXD6
About •	Received ※ 02 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 21 August 2022 — Issue date ※ 09 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYE3	Improvements to the Recycler/Main Injector to Deliver 850 kW+	resonance, proton, operation, experiment	578
	R. Ainsworth, P. Adamson, D. Capista, N. Chelidze, K.J. Hazelwood, I. Kourbanis, O. Mohsen, D.K. Morris, M.J. Murphy, M. Wren, M. Xiao Fermilab, Batavia, Illinois, USA C.E. Gonzalez-Ortiz MSU, East Lansing, Michigan, USA
	The Main Injector is used to deliver a 120 GeV high power proton beam for Neutrino experiments. The design power of 700 kW was reached in early 2017 but further improvements have seen a new sustained peak power of 893 kW. Two of the main improvements include the shortening of the Main Injector ramp length as well optimizing the slip-stacking procedure performed in the Recycler to reduce the amount of uncaptured beam making its way into the Main Injector. These improvements will be discussed in this paper as well future upgrades to reach higher beam powers.
	Slides WEYE3 [24.715 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEYE3
About •	Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 18 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPA12	Operational Experience of the New Booster Cryomodule at the Upgraded Injector Test Facility	cavity, cryomodule, simulation, experiment	640
	M.W. Bruker, R. Bachimanchi, J.M. Grames, M.D. McCaughan, J. Musson, P.D. Owen, T.E. Plawski, M. Poelker, T. Powers, H. Wang, Y.W. Wang JLab, Newport News, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. Since the early 1990s, the injector of the CEBAF accelerator at Jefferson Lab has relied on a normal-conducting RF graded-beta capture section to boost the kinetic energy of the electron beam from 100 / 130 keV to 600 keV for subsequent acceleration using a cryomodule housing two superconducting 5-cell cavities similar to those used throughout the accelerator. To simplify the injector design and improve the beam quality, the normal-conducting RF capture section and the cryomodule will be replaced with a new single booster cryomodule employing a superconducting, β = 0.6, 2-cell-cavity capture section and a single, β = 0.97, 7-cell cavity. The Upgraded Injector Test Facility at Jefferson Lab is currently hosting the new cryomodule to evaluate its performance with beam before installation at CEBAF. While demonstrating satisfactory performance of the booster and good agreement with simulations, our beam test results also speak to limitations of accelerator operations in a noisy, thermally unregulated environment.
	Poster WEPA12 [3.726 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA12
About •	Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 06 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYD4	Progress on the APS-U Injector Upgrade	injection, simulation, storage-ring, target	859
	J.R. Calvey, T. Fors, K.C. Harkay, U. Wienands ANL, Lemont, Illinois, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. For the APS-Upgrade, it was decided to leave the present APS injector chain in place and make individual improvements where needed. The main challenges faced by the injectors are delivering a high charge bunch (up to 16 nC in a single shot) to the storage ring, operating the booster synchrotron and storage ring at different rf frequencies, and maintaining good charge stability during APS-U operations. This paper will summarize recent progress on the injector upgrade. Topics include bucket targeting with the new injection/extraction timing system (IETS), modeling of high charge longitudinal instability in the PAR, and measurements of charge stability for different modes of operation.
	Slides THYD4 [2.015 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYD4
About •	Received ※ 19 July 2022 — Accepted ※ 11 August 2022 — Issue date ※ 22 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THZD3	Design of 3-GeV High-Gradient Booster for Upgraded Proton Radiography at LANSCE	proton, focusing, linac, quadrupole	891
	Y.K. Batygin, S.S. Kurennoy LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by US DOE under contract 89233218CNA000001 Increasing the proton beam energy from the present 800 MeV to 3 GeV will improve the resolution of the Proton Radiography Facility at the Los Alamos Neutron Science Center (LANSCE) by a factor of 10. It will bridge the gap between the existing facilities, which covers large length scales for thick objects, and future high-brightness light sources, which can provide the finest resolution. Proton radiography requires a sequence of short beam pulses (~20 x 80 ns) separated by intervals of variable duration, from about 300 ns to 1 to 2 μs. To achieve the required parameters, the high gradient 3-GeV booster is proposed. The booster consists of 1.4 GHz buncher, two accelerators based on 2.8 GHz and 5.6 GHz high-gradient accelerating structures and 1.4 GHz debuncher. Utilization of buncher-accelerator-debuncher scheme allows us to combine high-gradient acceleration with significant reduction of beam momentum spread. Paper discusses details of linac design and expected beam parameters.
	Slides THZD3 [2.348 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THZD3
About •	Received ※ 28 July 2022 — Revised ※ 06 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 04 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THZD4	Accelerating Structures for High-Gradient Proton Radiography Booster at LANSCE	cavity, linac, proton, distributed	894
	S.S. Kurennoy, Y.K. Batygin, E.R. Olivas LANL, Los Alamos, New Mexico, USA
	Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. We proposed accomplishing such an energy boost with a compact cost-effective linac based on normal conducting high-gradient (HG) RF accelerating structures. Such an unusual proton linac is feasible for proton radiography (pRad), which operates with short RF pulses. For a compact pRad booster at LANSCE, we have developed a multi-stage design: a short L-band section to capture and compress the 800-MeV proton beam followed by the main HG linac based on S- and C-band cavities, and finally, by an L-band de-buncher [1]. Here we present details of development, including EM and thermal-stress analysis, of proton HG structures with distributed RF coupling for the pRad booster. A simple two-cell structure with distributed coupling is being fabricated and will be tested at the LANL C-band RF Test Stand. [1] S.S. Kurennoy, Y.K. Batygin. IPAC21, MOPAB210.
	Slides THZD4 [1.591 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THZD4
About •	Received ※ 01 August 2022 — Revised ※ 10 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 26 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUZD1

The Electron-Positron Future Circular Collider (FCC-ee)

collider, operation, luminosity, electron

315

F. Zimmermann, M. Benedikt
CERN, Meyrin, Switzerland
K. Oide
DPNC, Genève, Switzerland
T.O. Raubenheimer
SLAC, Menlo Park, California, USA

Funding: Work supported by the European Union’s H2020 Framework Programme under grant agreement no.~951754 (FCCIS).
The Future Circular electron-positron Collider (FCC-ee) is aimed at studying the Z and W bosons, the Higgs, and top quark with extremely high luminosity and good energy efficiency. Responding to a request from the 2020 Update of the European Strategy for Particle Physics, in 2021 the CERN Council has launched the FCC Feasibility Study to examine the detailed implementation of such a collider. This FCC Feasibility Study will be completed by the end of 2025 and its results be presented to the next Update of the European Strategy for Particle Physics expected in 2026/27.

Slides TUZD1 [10.072 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUZD1

About •

Received ※ 03 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 21 August 2022 — Issue date ※ 02 September 2022

Cite •

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

TUPA18

Promise and Challenges of a Method for 5x5 Sigma Matrix Measurement in a Transport Line

quadrupole, extraction, emittance, simulation

382

M. Borland, V. Sajaev, K.P. Wootton
ANL, Lemont, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) is upgrading the storage ring to a design that requires on-axis injection. Matching between the incoming beam and the ring is important to ensure high injection efficiency. Toward this end, we have developed and tested a method for measuring all σ matrix elements except those related to the time coordinate. We report on challenges inherent in this technique, based on simulation and real-world trials.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA18

About •

Received ※ 29 July 2022 — Accepted ※ 05 August 2022 — Issue date ※ 29 September 2022

Cite •

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

TUPA22

Measurements of Bunch Length in the Advanced Photon Source Booster Synchrotron

synchrotron, detector, background, photon

394

J.C. Dooling, W. Berg, J.R. Calvey, K.C. Harkay, K.P. Wootton
ANL, Lemont, Illinois, USA

Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357.
A bunch duration monitor (BDM) was installed at the end of a synchrotron light monitor (SLM) port in the Advanced Photon Source (APS) booster synchrotron. The BDM is based on a fast Hamamatsu metal-semiconductor-metal detector with nominal rise and fall times of 30 ps. Bunch length data is especially important as the bunch charge will be raised from 3 nC, used in the existing machine, to as much as 18 nC for APS-Upgrade operation. During preliminary high-charge studies, the SLM image is observed to move over a period of minutes while the BDM signal intensity varies; the motion is likely due to thermal loading of the in-tunnel synchrotron light mirror. Work is underway to stabilize the position using a simple feedback system and motorized mirror mount, as well as a new synchrotron light mirror assembly with improved thermal load handling. The feedback system will maintain optical alignment on the BDM at an optimum position based on the SLM centroid location. The optical layout and feedback system will be presented along with preliminary bunch length data.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA22

About •

Received ※ 04 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 09 September 2022

Cite •

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

TUPA23

First Beam Results Using the 10-kW Harmonic Rf Solid-State Amplifier for the APS Particle Accumulator Ring

injection, photon, rf-amplifier, linac

398

K.C. Harkay, T.G. Berenc, J.R. Calvey, J.C. Dooling, H. Shang, T.L. Smith, Y. Sun, U. Wienands
ANL, Lemont, Illinois, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) particle accumulator ring (PAR) was designed to accumulate linac pulses into a single bunch using a fundamental radio frequency (rf) system, and longitudinally compress the beam using a harmonic rf system prior to injection into the booster. The APS Upgrade injectors will need to supply full-current bunch replacement with high single-bunch charge for swap-out injection in the new storage ring. Significant bunch lengthening is observed in the PAR at high charge, which negatively affects beam capture in the booster. Predictions showed that the bunch length could be compressed to better match the booster acceptance using a combination of higher beam energy and higher harmonic gap voltage. A new 10-kW harmonic rf solid-state amplifier (SSA) was installed in 2021 to raise the gap voltage and improve bunch compression. The SSA has been operating reliably. Initial results show that the charge-dependent bunch lengthening in PAR with higher gap voltage agrees qualitatively with predictions. A tool was written to automate bunch length data acquisition. Future plans to increase the beam energy, which makes the SSA more effective, will also be summarized.

Poster TUPA23 [2.477 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA23

About •

Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 07 October 2022

Cite •

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

TUPA38

Sublinear Intensity Response of Cerium-Doped Yttrium Aluminium Garnet Screen with Charge

electron, FEL, linac, storage-ring

437

K.P. Wootton, A.H. Lumpkin
ANL, Lemont, Illinois, USA

Funding: This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
Swap-out injection to the Advanced Photon Source Upgrade storage ring necessitates the injection of ~17 nC electron bunches at 6 GeV. To aid with machine tune-up and to measure the beam size, diagnostic imaging screens are envisaged at several locations in the beam transport line from the booster synchrotron to the storage ring. As such, it is important to determine whether the response of these screens to charge is linear. In the present work, we examine the effect of sublinear intensity quenching of a Cerium-doped Yttrium-Aluminium-Garnet scintillator screen. A 1.3 megapixel FLIR BlackFly monochrome digital camera was used to image the beam at the scintillator. At 7 GeV beam energy, over the charge densities investigated (<10 fC um^-2), an approximately 10 % reduction of the imaging intensity due to quenching of the scintillator was observed.

Poster TUPA38 [0.557 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA38

About •

Received ※ 02 August 2022 — Accepted ※ 03 August 2022 — Issue date ※ 09 August 2022

Cite •

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

WEXD6

Electron Cloud Measurements in Fermilab Booster

electron, simulation, proton, laser

556

S.A.K. Wijethunga, J.S. Eldred, E. Pozdeyev, C.-Y. Tan
Fermilab, Batavia, Illinois, USA

Fermilab Booster synchrotron requires an intensity upgrade from 4.5×10¹² to 6.5×10¹² protons per pulse as a part of Fermilab’s Proton Improvement Plan-II (PIP-II). One of the factors which may limit the high-intensity performance is the fast transverse instabilities caused by electron cloud effects. According to the experience in the Recycler, the electron cloud gradually builds up over multiple turns in the combined function magnets and can reach final intensities orders of magnitude greater than in a pure dipole. Since the Booster synchrotron also incorporates combined function magnets, it is important to discover any existence of an electron cloud. And if it does, its effects on the PIP-II era Booster and whether mitigating techniques are required. As the first step, the presence or absence of the electron cloud was investigated using a gap technique. This paper presents experimental details and observations of the bunch-by-bunch tune shifts of beams with various bunch train structures at low and high intensities and simulation results conducted using PyECLOUD software.

Slides WEXD6 [4.483 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEXD6

About •

Received ※ 02 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 21 August 2022 — Issue date ※ 09 September 2022

Cite •

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

WEYE3

Improvements to the Recycler/Main Injector to Deliver 850 kW+

resonance, proton, operation, experiment

578

R. Ainsworth, P. Adamson, D. Capista, N. Chelidze, K.J. Hazelwood, I. Kourbanis, O. Mohsen, D.K. Morris, M.J. Murphy, M. Wren, M. Xiao
Fermilab, Batavia, Illinois, USA
C.E. Gonzalez-Ortiz
MSU, East Lansing, Michigan, USA

The Main Injector is used to deliver a 120 GeV high power proton beam for Neutrino experiments. The design power of 700 kW was reached in early 2017 but further improvements have seen a new sustained peak power of 893 kW. Two of the main improvements include the shortening of the Main Injector ramp length as well optimizing the slip-stacking procedure performed in the Recycler to reduce the amount of uncaptured beam making its way into the Main Injector. These improvements will be discussed in this paper as well future upgrades to reach higher beam powers.

Slides WEYE3 [24.715 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEYE3

About •

Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 18 August 2022

Cite •

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

WEPA12

Operational Experience of the New Booster Cryomodule at the Upgraded Injector Test Facility

cavity, cryomodule, simulation, experiment

640

M.W. Bruker, R. Bachimanchi, J.M. Grames, M.D. McCaughan, J. Musson, P.D. Owen, T.E. Plawski, M. Poelker, T. Powers, H. Wang, Y.W. Wang
JLab, Newport News, Virginia, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
Since the early 1990s, the injector of the CEBAF accelerator at Jefferson Lab has relied on a normal-conducting RF graded-beta capture section to boost the kinetic energy of the electron beam from 100 / 130 keV to 600 keV for subsequent acceleration using a cryomodule housing two superconducting 5-cell cavities similar to those used throughout the accelerator. To simplify the injector design and improve the beam quality, the normal-conducting RF capture section and the cryomodule will be replaced with a new single booster cryomodule employing a superconducting, β = 0.6, 2-cell-cavity capture section and a single, β = 0.97, 7-cell cavity. The Upgraded Injector Test Facility at Jefferson Lab is currently hosting the new cryomodule to evaluate its performance with beam before installation at CEBAF. While demonstrating satisfactory performance of the booster and good agreement with simulations, our beam test results also speak to limitations of accelerator operations in a noisy, thermally unregulated environment.

Poster WEPA12 [3.726 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA12

About •

Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 06 September 2022

Cite •

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

THYD4

Progress on the APS-U Injector Upgrade

injection, simulation, storage-ring, target

859

J.R. Calvey, T. Fors, K.C. Harkay, U. Wienands
ANL, Lemont, Illinois, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
For the APS-Upgrade, it was decided to leave the present APS injector chain in place and make individual improvements where needed. The main challenges faced by the injectors are delivering a high charge bunch (up to 16 nC in a single shot) to the storage ring, operating the booster synchrotron and storage ring at different rf frequencies, and maintaining good charge stability during APS-U operations. This paper will summarize recent progress on the injector upgrade. Topics include bucket targeting with the new injection/extraction timing system (IETS), modeling of high charge longitudinal instability in the PAR, and measurements of charge stability for different modes of operation.

Slides THYD4 [2.015 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYD4

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Received ※ 19 July 2022 — Accepted ※ 11 August 2022 — Issue date ※ 22 August 2022

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THZD3

Design of 3-GeV High-Gradient Booster for Upgraded Proton Radiography at LANSCE

proton, focusing, linac, quadrupole

891

Y.K. Batygin, S.S. Kurennoy
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by US DOE under contract 89233218CNA000001
Increasing the proton beam energy from the present 800 MeV to 3 GeV will improve the resolution of the Proton Radiography Facility at the Los Alamos Neutron Science Center (LANSCE) by a factor of 10. It will bridge the gap between the existing facilities, which covers large length scales for thick objects, and future high-brightness light sources, which can provide the finest resolution. Proton radiography requires a sequence of short beam pulses (~20 x 80 ns) separated by intervals of variable duration, from about 300 ns to 1 to 2 μs. To achieve the required parameters, the high gradient 3-GeV booster is proposed. The booster consists of 1.4 GHz buncher, two accelerators based on 2.8 GHz and 5.6 GHz high-gradient accelerating structures and 1.4 GHz debuncher. Utilization of buncher-accelerator-debuncher scheme allows us to combine high-gradient acceleration with significant reduction of beam momentum spread. Paper discusses details of linac design and expected beam parameters.

Slides THZD3 [2.348 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THZD3

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Received ※ 28 July 2022 — Revised ※ 06 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 04 October 2022

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THZD4

Accelerating Structures for High-Gradient Proton Radiography Booster at LANSCE

cavity, linac, proton, distributed

894

S.S. Kurennoy, Y.K. Batygin, E.R. Olivas
LANL, Los Alamos, New Mexico, USA

Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. We proposed accomplishing such an energy boost with a compact cost-effective linac based on normal conducting high-gradient (HG) RF accelerating structures. Such an unusual proton linac is feasible for proton radiography (pRad), which operates with short RF pulses. For a compact pRad booster at LANSCE, we have developed a multi-stage design: a short L-band section to capture and compress the 800-MeV proton beam followed by the main HG linac based on S- and C-band cavities, and finally, by an L-band de-buncher [1]. Here we present details of development, including EM and thermal-stress analysis, of proton HG structures with distributed RF coupling for the pRad booster. A simple two-cell structure with distributed coupling is being fabricated and will be tested at the LANL C-band RF Test Stand.
[1] S.S. Kurennoy, Y.K. Batygin. IPAC21, MOPAB210.

Slides THZD4 [1.591 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THZD4

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Received ※ 01 August 2022 — Revised ※ 10 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 26 September 2022

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