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Sereno, N.

Publications and source records attributed to Sereno, N..

Beam Dynamics of the Strong Hadron Cooler ERL at the Electron-Ion Collider

The Strong Hadron Cooler Energy Recovery Linac (SHC-ERL) for the Electron-Ion Collider (EIC) is required to produce an electron beam with a bunch charge of 1 nC, an average current of 100 mA, and a beam energy of both 150 and 55 MeV, with strict requirements for the transverse emittance, slice energy spread, and longitudinal distribution. This paper covers the design in detail, including preliminary considerations of higher order effects and diagnostics.

Deitrick, K.↗

Design Overview of the Strong Hadron Cooler ERL at the Electron-Ion Collider

The Electron-Ion Collider (EIC) is currently under development to be built at Brookhaven National Lab and requires cooling during collisions in order to preserve the quality of the hadron beam despite degradation due to intra-beam scattering and beam-beam effect. An Energy Recovery Linac (ERL) is being designed to deliver the necessary electron beam for Coherent electron Cooling (CeC) of the hadron beam, with an electron bunch charge of 1 nC and an average current of 100 mA; two modes of operation are being developed for 150 and 55 MeV electrons, corresponding to 275 and 100 GeV protons. The injector of this Strong Hadron Cooler ERL (SHC-ERL) is shared with the Injection Cooler ERL, which cools lower energy proton beams via bunched beam cooling, as used in the Low Energy RHIC electron Cooling (LEReC). This talk introduces the layout and presents a high-level overview of the design.

Deitrick, K.↗

OPTIMIZATION OF COOLING DISTRIBUTION OF THE EIC SHC COOLER ERL

The Electron-Ion Collider (EIC) Hadron Storage Ring (HSR) will use strong hadron cooling to maintain the beam brightness and high luminosity during long collision ex?periments. An Energy Recovery Linac is used to deliver the high-current high-brightness electron beam for cooling. For the best cooling effect, the electron beam requires low emittance, small energy spread, and uniform longitudinal distribution. In this work, we simulate and optimize the longitudinal laser-beam distribution shaping at the photo?cathode, modeling space charge forces accurately. Machine parameters such as RF cavity phases are optimized in con?junction with the beam distribution using a genetic optimizer. We demonstrate improvement of the cooling distribution in key parameters.

Wang, N.↗

Development of an ERL for Coherent Electron Cooling at the Electron-Ion Collider

The Electron-Ion Collider (EIC) is currently under development to be built at Brookhaven National Lab and requires cooling during collisions in order to mitigate the hadron beam emittance degradation due to intra-beam scattering and beam-beam effects. An Energy Recovery Linac (ERL) is being designed to deliver the necessary electron beam for Coherent electron Cooling (CeC) of the hadron beam, with an electron bunch charge of 1 nC and an average current of 100 mA; two modes of operation are being developed for 150 and 55 MeV electrons, corresponding to 275 and 100 GeV protons. The injector of this Strong Hadron Cooler ERL (SHC-ERL) is shared with the Pre-cooler ERL, which cools lower energy proton beams via bunched beam cooling, as used in the Low Energy RHIC electron Cooling (LEReC). This paper reviews the current state of the design.

Deitrick, K.↗

A Preliminary Feasibility Study on Multi-Cavity Cryomodule Integration for the Electron Ion Collider Energy Recover Linac Cooler

The Electron-Ion Collider (EIC) is a state-of-the-art accelerator designed for collisions between highly polarized electrons and ions. To achieve optimal luminosity, the ion beam is cooled using an electron beam sourced from an energy recovery linac (ERL). In the current ERL baseline design, one BNL type RF cavity is used per cryomodule, leading to spatial and cost challenges. This study examines the feasibility of using more compact PERLE (Powerful Energy Recovery Linac for Experiments) type cavities, which can house multiple cavities within a single cryomodule, by evaluating their Beam Breakup (BBU) instability performance. Higher Order Modes (HOM) parameters were obtained through frequency scaling, assuming constant quality factor Q_L, R/Q, and linearly scaling HOM frequencies. To predict the BBU threshold current and ensure accuracy, two different BBU tracking simulations are used for cross-verification. Although the reduced footprint of PERLE-type cavities is advantageous, maintaining sufficient damping of HOMs remains crucial. Finally, we compare the HOM damping efficiency of both cavity types and suggest a pathway forward.

Deitrick, K.↗

THz and Sub-THz Capabilities of a Table-Top Radiation Source Driven by an RF Thermionic Electron Gun

Design features and experimental results are presented for a sub-mm wave source [1] based on APS RF thermionic electron gun. The setup includes compact alpha-magnet, quadrupoles, sub-mm-wave radiators, and THz optics. The sub-THz radiator is a planar, oversized structure with gratings. Source upgrade for generation frequencies above 1 THz is discussed. The THz radiator will use a short-period undulator having 1 T field amplitude, ~20 cm length, and integrated with a low-loss oversized waveguide. Both radiators are integrated with a miniature horn antenna and a small ~90°-degree in-vacuum bending magnet. The electron beamline is designed to operate different modes including conversion to a flat beam interacting efficiently with the radiator. The source can be used for cancer diagnostics, surface defectoscopy, and non-destructive testing. Sub-THz experiment demonstrated a good potential of a robust, table-top system for generation of a narrow bandwidth THz radiation. This setup can be considered as a prototype of a compact, laser-free, flexible source capable of generation of long trains of Sub-THz and THz pulses with repetition rates not available with laser-driven sources.

Smirnov, Alexei V.↗

Advanced Photon Source Status Report

Here, the Advanced Photon Source is a 7-GeV, third-generation synchrotron light source that provides x-rays in a wide range of spectra from a few keV to a hundred keV to 48 insertion device and 23 bending magnet beamlines for about 5000 hours per year.

43 PARTICLE ACCELERATORS↗

Performance Test of the Next Generation X-Ray Beam Position Monitor System for The APS Upgrade

The Advanced Photon Source is developing its next major upgrade (APS-U) based on the multi-bend achromat lattice. Improved beam stability is critical for the upgrade and will require keeping short-time beam angle change below 0.25 µrad and long-term angle drift below 0.6 µrad. A reliable white x-ray beam diagnostic system in the front end will be a key part of the planned beam stabilization system. This system includes an x-ray beam position monitor (XBPM) based on x-ray fluorescence (XRF) from two specially designed GlidCop A-15 absorbers, a second XBPM using XRF photons from the Exit Mask, and two white beam intensity monitors using XRF from the photon shutter and Compton-scattered photons from the front end beryllium window or a retractable diamond film in windowless front ends. We present orbit stability data for the first XBPM used in the feedback control during user operations, as well as test data from the second XBPM and the intensity monitors. They demonstrate that the XBPM system meets APS-U beam stability requirements.

Yang, B.↗

BPM STABILTIY STUDIES FOR THE APS MBA UPGRADE

The Advanced Photon Source (APS) is currently in the preliminary design phase for the multi-bend achromat (MBA) lattice upgrade. Beam stability is critical for the MBA and will require long term drift defined as beam mo-tion over a seven-day timescale to be no more than 1 mi-cron at the insertion device locations and beam angle change no more than 0.25 micro-radian. Mechanical stabil-ity of beam position monitor (BPM) pickup electrodes mounted on insertion device vacuum chambers place a fun-damental limitation on long-term beam stability for inser-tion device beamlines. We present the design and imple-mentation of prototype mechanical motion system (MMS) instrumentation for quantifying this type of motion specif-ically in the APS accelerator tunnel and experiment hall floor under normal operating conditions. The MMS pres-ently provides critical position information on the vacuum chamber and BPM support systems. Initial results of the R&D prototype systems have demonstrated that the cham-ber movements far exceed the long-term drift tolerance specified for the APS Upgrade MBA storage ring.

Lill, R.↗

Progress on the development of the next generation x-ray beam position monitors at the advanced photon source

Accurate and stable x-ray beam position monitors (XBPMs) are key elements in obtaining the desired user beam stability in the Advanced Photon Source (APS). The next generation XBPMs for high heat load front ends (HHL FEs) have been designed to meet these requirements by utilizing Cu K-edge x-ray fluorescence (XRF) from a pair of copper absorbers and have been installed at the front ends (FEs) of the APS. Commissioning data showed a significant performance improvement over the existing photoemission-based XBPMs. While a similar design concept can be applied for the canted undulator front ends, where two undulator beams are separated by 1.0-mrad, the lower beam power (< 10 kW) per undulator allows us to explore lower-cost solutions based on Compton scattering from the diamond blades placed edge-on to the x-ray beam. A prototype of the Compton scattering XBPM system was installed at 24-ID-A in May 2015. In this report, the design and test results for XRF-based XBPM and Compton scattering based XBPM are presented. Ongoing research related to the development of the next generation XBPMs on thermal contact resistance of a joint between two solid bodies is also discussed.

43 PARTICLE ACCELERATORS↗