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Lin, Fanglei

Publications and source records attributed to Lin, Fanglei.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

The EIC accelerator: design highlights and project status

The design of the electron-ion collider (EIC) at Brookhaven National Laboratory is well underway, aiming at a peak electron-proton luminosity of 10e+34 cm^-1·sec^-1. This high luminosity, the wide center-of-mass energy range from 29 to 141 GeV (e-p) and the high level of polarization require innovative solutions to maximize the performance of the machine, which makes the EIC one of the most challenging accelerator projects to date. The complexity of the EIC will be discussed, and the project status and plans will be presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Perspective of a Dual Energy Electron Storage Ring Cooler for a Hadron Beam Cooling

A dual energy electron storage ring cooler was proposed and explored to maintain a good hadron beam quality against intra-beam scattering and all heating sources in a collider. The unique configuration of this concept is that electron beam in the low energy section extracts heat away from the hadron beam through Coulomb interaction while electron beam in the high energy section releases heat through its intrinsic synchrotron radiation damping. The early design employs a magnetized electron beam for achieving a high cooling efficiency. Recently, a non-magnetized cooling electron beam was explored in this dual energy cooler. It could meet the same cooling requirements while lowering the risks. This paper presents study results on design and optimization of a dual energy storage ring cooler and describes the trade-offs between using magnetized and non-magnetized cooling for this approach.

Lin, Fanglei↗
DOE OSTI2023

Design Status of the Electron-Ion Collider

The Electron-Ion Collider is gearing up for "Critical Decision 2", theproject baseline with defined scope, cost and schedule.Lattice designs are beingfinalized, and preliminary component design is being carried out. Beam dynamicsstudies such as dynamic aperture optimization, instability and polarizationstudies, and beam-beam simulations are continuing in parallel. We report onthe latest developments and the overall status of the project, and presentthe plans for future activities.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

ERL-BASED COMPACT X-RAY FEL

We propose to develop an energy-recovery-linac (ERL)- based X-ray free-electron laser (XFEL). Taking advantage of the demonstrated high-efficiency energy recovery of the beam power in the ERL, the proposed concept offers the following benefits: i) recirculating the electron beam through high-gradient superconducting RF (SRF) cavities shortens the linac, ii) energy recovery in the SRF linac saves the klystron power and reduces the beam dump power, iii) the high average beam power produces a high average photon brightness. In addition, such a concept has the capability of delivering optimized high-brightness CW X-ray FEL performance at different energies with simultaneous multipole sources. In this paper, we will present the preliminary results on the study of feasibility, optics design and parameter optimization of such a device.

Lin, Fanglei↗
DOE OSTI2022

ERL-Based Compact X-Ray FEL

We propose to develop an energy-recovery-linac (ERL)-based X-ray free-electron laser (XFEL). Taking advantage of the demonstrated high-efficiency energy recovery of the beam power in the ERL, the proposed concept offers the following benefits: i) recirculating the electron beam through high-gradient superconducting RF (SRF) cavities shortens the linac, ii) energy recovery in the SRF linac saves the klystron power and reduces the beam dump power, iii) the high average beam power produces a high average photon brightness. In addition, such a concept has the capability of delivering optimized high-brightness CW X-ray FEL performance at different energies with simultaneous multipole sources. In this paper, we will present the preliminary results on the study of feasibility, optics design and parameter optimization of such a device.

Lin, Fanglei↗
DOE OSTI2019

Multipole effects on dynamic aperture in JLEIC ion collider ring

In a collider, stronger focusing at the interaction point (IP) for low beta-star and high luminosity produces large beams at final focusing quadrupoles (FFQs). To achieve the high luminosity requirement in the Jefferson Lab Electron-Ion Collider (JLEIC), the interaction region (IR) beta functions peak at ~4.2 km in downstream FFQs. These large beta functions and FFQ multipoles reduce the dynamic aperture (DA) of the ring. A study of the multipole effects on the DA was performed to determine limits on multipoles, and to include a multipole compensation scheme to increase the DA and beam lifetime.

Rajput-Ghoshal, Renuka↗
DOE OSTI2019

Interaction Region Magnets for Future Electron-Ion Collider ¿at Jefferson Lab

The Jefferson Lab Electron Ion Collider (JLEIC) is a pro-posed new machine for nuclear physics research. It uses the existing CEBAF accelerator as a full energy injector to deliver 3 to 12 GeV electrons into a new electron collider ring. An all new ion accelerator and collider complex will deliver up to 200 GeV protons. The machine has luminosity goals of 1034 cm-2 sec-1. The whole detector region including forward detection covers about 80 meters of the JLEIC complex. The interaction region design has recently been optimized to accommodate 200 GeV proton energy using conventional NbTi superconducting magnet technology. This paper will describe the requirements and preliminary designs for both the ion and electron beam magnets in the most complex 34.5 m long interaction region (IR) around the interaction point (IP). The interaction region has over thirty-four superconducting magnets operating at 4.5K; these include dipoles, quadrupoles, skew quadrupoles, solenoids, horizontal and vertical correctors and higher order multipole magnets. The paper will also dis-cuss the electromagnetic interaction between these magnets.

Rajput-Ghoshal, Renuka↗
DOE OSTI2019

Simulation of Transparent Spin Experiment in RHIC

The transparent spin mode has been proposed as a new technique for preservation and control of the spin polarization of an ion beam in a synchrotron. The ion rings of the proposed Jefferson Lab Electron-Ion Collider adopted this technique in their figure-8 design. The transparent spin mode can also be setup in a racetrack with two identical Siberian snakes. There is a proposal to test the predicted features of the spin transparent mode in RHIC, which already has all of the necessary hardware capabilities. We have earlier analytically estimated the setup parameters and developed a preliminary experimental plan. In this paper we describe simulations of the proposed experiment using a Zgoubi model of RHIC. We present simulation of the polarization preservation during acceleration in the transparent spin mode. We also demonstrate polarization control by simulating an adiabatic polarization adjustment. A procedure to measure the strength of the spin transparent resonance is illustrated.

Morozov, Vasiliy↗
DOE OSTI2019

Interaction Region Magnets for Future Electron-Ion Collider at Jefferson Lab

The Jefferson Lab Electron Ion Collider (JLEIC) is a pro-posed new machine for nuclear physics research. It uses the existing CEBAF accelerator as a full energy injector to deliver 3 to 12 GeV electrons into a new electron collider ring. An all new ion accelerator and collider complex will deliver up to 200 GeV protons. The machine has luminosity goals of 1034 cm-2 sec-1. The whole detector region including forward detection covers about 80 meters of the JLEIC complex. The interaction region design has recently been optimized to accommodate 200 GeV proton energy using conventional NbTi superconducting magnet technology. This paper will describe the requirements and preliminary designs for both the ion and electron beam magnets in the most complex 34.5 m long interaction region (IR) around the interaction point (IP). The interaction region has over thirty-four superconducting magnets operating at 4.5K; these include dipoles, quadrupoles, skew quadrupoles, solenoids, horizontal and vertical correctors and higher order multipole magnets. The paper will also dis-cuss the electromagnetic interaction between these magnets.

Rajput-Ghoshal, Renuka↗
DOE OSTI2019

Conceptual Design of the Interaction Region Magnets for Future Electron-Ion Collider at Jefferson Lab

The Jefferson Lab Electron Ion Collider (JLEIC) is a proposed new machine for nuclear physics research. As proposed, it will deliver between 15 and 65 GeV center of mass energy collisions between electrons and nuclei. It uses the existing CEBAF accelerator as a full energy injector to deliver 3 to 10 GeV electrons into a new electron collider ring. An all new ion accelerator and collider complex will deliver up to 100 GeV protons, or 40 GeV/nucleon ions. The machine will have luminosity goals of above 1033 cm-2 sec-1 in the whole energy range with a maximum of a few 1034 cm-2 sec-1. The two collider rings use a unique figure-of eight layout to deliver a high degree of polarization in both beams. The machine will include room for two interaction regions with only one initially installed. The crossing angle in the primary interaction region will be 50 mrad. The whole detector region including forward detection covers about 80 meters of the JLEIC complex. This paper will describe the requirements and preliminary designs for both the ion and electron beam magnets in the most complex 32 m long interaction region (IR) around the interaction point (IP). The interaction region has over thirty-seven superconducting magnets operating at 4.5K; these include dipoles, quadrupoles, skew-quadrupoles, solenoids, horizontal and vertical correctors and higher order multipole magnets. The paper will also discuss the electromagnetic interaction between these magnets.

Wiseman, Mark (ORCID:0000000179110306)↗
DOE OSTI2018

Beam formation in the alternative JLEIC ion complex

The proposed alternative design approach for the JLab-EIC (JLEIC) ion complex uses a more compact linac and pre-booster, and consolidates the electron storage ring (ering) as a large booster for the ions. Following a parameter study showing the feasibility of this design approach, we have adapted the e-ring lattice by adding RF sections to accelerate ion beams. In this study, we focus on the transverse beam formation for protons and lead ions from the ion source to collision point including the linac, pre-booster, e-ring and collider ring. Effects such as stripping injection, space charge, intra-beam scattering and beam cooling determine the total charge accumulated in each ring and the final luminosity of the collider.

Mustapha, Brahim↗
DOE OSTI2018

STATUS OF THE JLEIC ION COLLIDER RING DESIGN

We present an update on the lattice design and beam dynamics study of the ion collider ring of JLEIC (Jefferson Lab Electron Ion Collider). The collider ring consists of two 261.7 degree arcs connected by two straight sections crossing each other. One of the straights houses an interaction region (IR) and is shaped to make a 50 mrad crossing angle with the electron beam at the interaction point (IP) to meet physics requirements. The forward acceptance requirements downstream of the IP in the ion direction lead to an asymmetric IR lattice design. The detector solenoid effects and the multipole fields of the IR magnets further complicate this picture. In this paper, compensation of the detector solenoid effects is considered together with orbit correction and multipole effects. We also study local compensation of the magnet multipoles using dedicated multipole correctors. And an optimization of the betatron tunes is also presented.

Wei, Guohui↗
DOE OSTI2018

Analysis of Spin Response Function at Beam Interaction Point in JLEIC

The spin response function is determined by a collid-er’s magnetic lattice and allows one to account for con-tributions of perturbing fields to spin resonance strengths. The depolarizing effect of an incoming beam depends significantly on the response function value at the interaction point (IP). We present an analytic calcula-tion of the response function for protons and deuterons at the IP of Jefferson Lab Electron Ion Collider (JLEIC) over its whole momentum range. We find a good agreement of the analytic calculation with our numerical modeling results obtained using a spin tracking code, Zgoubi.

Derbenev, Yaroslav S.↗
DOE OSTI2017

Acceleration of polarized protons and deuterons in the ion collider ring of JLEIC

The figure-8-shaped ion collider ring of Jefferson Lab Electron-Ion Collider (JLEIC) is transparent to the spin. It allows one to preserve proton and deuteron polarizations using weak stabilizing solenoids when accelerating the beam up to 100 GeV/c. When the stabilizing solenoids are introduced into the collider's lattice, the particle spins precess about a spin field, which consists of the field induced by the stabilizing solenoids and the zero-integer spin resonance strength. During acceleration of the beam, the induced spin field is maintained constant while the resonance strength experiences significant changes in the regions of "interference peaks". The beam polarization depends on the field ramp rate of the arc magnets. Its component along the spin field is preserved if acceleration is adiabatic. We present the results of our theoretical analysis and numerical modeling of the spin dynamics during acceleration of protons and deuterons in the JLEIC ion collider ring. We demonstrate high stability of the deuteron polarization in figure-8 accelerators. We analyze a change in the beam polarization when crossing the transition energy.

Kondratenko, A.↗
DOE OSTI2017

Study of Electron Polarization Dynamics in the JLEIC at Jlab

The design of an electron polarization scheme in the Jefferson Lab Electron-Ion Collider (JLEIC) aims to attain a high longitudinal electron polarization (over 70%) at collision points as required by the nuclear physics program. Comprehensive strategies for achieving this goal have been considered and developed including injection of highly polarized electrons from CEBAF, mechanisms for manipulation and preservation of the polarization in the JLEIC collider ring and measurement of the electron polarization. In particular, maintaining a sufficiently long polarization lifetime is crucial for accumulation of adequate experimental statistics. The chosen electron polarization configuration, based on the unique figure-8 geometry of the ring, removes the electron spin-tune energy dependence. This significantly simplifies the control of the electron polarization and suppresses the synchrotron sideband resonances. This paper reports recent studies and simulations of the electron polarization dynamics in the JLEIC electron collider ring.

Lin, Fanglei↗
DOE OSTI2016

DECOUPLING AND MATCHING OF ELECTRON COOLING SECTION IN THE MEIC ION COLLIDER RING

To get a luminosity level of 10-33 cm-2sec-1 at all design points of the MEIC, small transverse emittance is necessary in the ion collider ring, which is achieved by an electron cooling. And for the electron cooling, two solenoids are used to create a cooling environment of temperature exchange between electron beam and ion beam. However, the solenoids can also give coupling and matching problem to the optics of the MEIC ion ring lattice. Both of them will have influences on the IP section and other areas, especially for the beam size, Twiss parameters, and nonlinear effects. A symmetric and flexible method is used to deal with these problems. With this method, the electron cooling section is merged into the ion ring lattice elegantly.

Wei, G.H.↗