Boris Podobedov
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View article: Dynamic Focusing to Suppress Emittance Transfer in Crab-Crossing Flat Beam Collisions
Dynamic Focusing to Suppress Emittance Transfer in Crab-Crossing Flat Beam Collisions Open
Flat hadron beam collisions, though expected to enhance peak luminosity by about an order of magnitude, have not yet been demonstrated. Our study reveals a critical limitation: realistic fluctuations, when amplified by synchro-betatron res…
View article: Status of the Proton EDM Experiment (pEDM)
Status of the Proton EDM Experiment (pEDM) Open
The Proton EDM Experiment (pEDM) is the first direct search for the proton electric dipole moment (EDM) with the aim of being the first experiment to probe the Standard Model (SM) prediction of any particle EDM. Phase-I of pEDM will achiev…
View article: The EIC accelerator: design highlights and project status
The EIC accelerator: design highlights and project status Open
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…
View article: Recent Beam Stability Analysis for the EIC
Recent Beam Stability Analysis for the EIC Open
This document summarizes work done in WBS 6.02.02 during FY23. Additional details can be found in the EIC overview paper presented at IPAC’23 [1], and the references therein. Progress has been made in the ESR and HSR lattice design, dynami…
View article: Eddy Current Shielding of the Magnetic Field Ripple in the EIC Electron Storage Ring Vacuum Chambers
Eddy Current Shielding of the Magnetic Field Ripple in the EIC Electron Storage Ring Vacuum Chambers Open
The EIC electron storage ring (ESR) has very tight tolerances for the beam position and size stability at the interaction point. The oscillations at the proton betatron frequency and its harmonics are the most dangerous because, for instan…
View article: Design status of the Electron-Ion Collider
Design status of the Electron-Ion Collider Open
The Electron-Ion Collider is gearing up for "Critical Decision 2", the project baseline with defined scope, cost and schedule. Lattice designs are being finalized, and preliminary component design is being carried out. Beam dynamics studie…
View article: ESR Dipole Power Supply Current Ripple and Noise Specifications
ESR Dipole Power Supply Current Ripple and Noise Specifications Open
This note presents key findings for the ESR main magnet dipole power supplies (PS), where we find the current ripple specification to be close to or beyond the state-of-the-art. These specifications originate from beam-beam considerations,…
View article: rf cavity point-charge wakefield computation through a hybrid analytical and numerical approach
rf cavity point-charge wakefield computation through a hybrid analytical and numerical approach Open
We study short-range geometric wakefields of a normal conducting third harmonic cavity, developed by ALBA, which is currently under investigation for the BESSY II main storage ring upgrade. As is commonly done to enhance the shunt impedanc…
View article: High power density soft x-ray GaAs photodiodes with tailored spectral response
High power density soft x-ray GaAs photodiodes with tailored spectral response Open
GaAs photodiode arrays have been designed for non-destructive monitoring of x-ray beam position in soft coherent beamline front ends in synchrotron light sources. A shallow p-on-n junction was employed to reduce the device photocurrent den…
View article: The storage ring proton EDM experiment
The storage ring proton EDM experiment Open
We describe a proposal to search for an intrinsic electric dipole moment (EDM) of the proton with a sensitivity of \targetsens, based on the vertical rotation of the polarization of a stored proton beam. The New Physics reach is of order $…
View article: Electric dipole moments and the search for new physics
Electric dipole moments and the search for new physics Open
Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well beyond those reached directly at high energy colliders. Discrimination between different physics models, however, requires…
View article: Electric dipole moments and the search for new physics
Electric dipole moments and the search for new physics Open
Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well beyond those reached directly at high energy colliders. Discrimination between different physics models, however, requires…
View article: ESR Magnet Vibrational Specifications for Dynamic Orbit Stability at the IP
ESR Magnet Vibrational Specifications for Dynamic Orbit Stability at the IP Open
motion coupling to the quadrupole supports, but one should not assume that ground motion is the unique source.
View article: Non-Invasive Dispersion Function Measurement during Light Source Operations
Non-Invasive Dispersion Function Measurement during Light Source Operations Open
We implemented a completely parasitic measurement of lattice dispersion functions in both horizontal and vertical planes, which is fully compatible with light source user operations. The measurement is performed by applying principal compo…
View article: Design Status Update of the Electron-Ion Collider
Design Status Update of the Electron-Ion Collider Open
The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community…
View article: An Overview of the Collective Effects and Impedance Calculation for the EIC
An Overview of the Collective Effects and Impedance Calculation for the EIC Open
A new high-luminosity Electron-Ion Collider (EIC) is being designed at Brookhaven National Laboratory (BNL). Stable operation of the electron beam at an average current of 2.5A within 1100 bunches with a 7mm bunch length is one of the chal…
View article: Progress Towards Soft X-Ray Beam Position Monitor Development
Progress Towards Soft X-Ray Beam Position Monitor Development Open
X-ray beam position monitors (BPMs) are instrumental for storage ring light sources, where they reliably provide positional measurements of high-power beams in hard X-ray beamlines. However, despite a growing need, coming especially from c…
View article: Amplitude-Dependent Shift of Betatron Tunes and Its Relation to Long-Term Circumference Variations at NSLS-II
Amplitude-Dependent Shift of Betatron Tunes and Its Relation to Long-Term Circumference Variations at NSLS-II Open
The comparison of amplitude tune dependence measured for NSLSII lattices with models indicated the large change of amplitude tune dependence over time apparently can not be solely explained by magnets variation or beta function changes, bu…
View article: Limiting Coherent Longitudinal Beam Oscillations in the EIC Electron Storage Ring
Limiting Coherent Longitudinal Beam Oscillations in the EIC Electron Storage Ring Open
We study coherent longitudinal beam oscillations in the EIC electron storage ring (ESR). We show that to avoid unacceptable hadron emittance growth due to finite crossing angle, the amplitude of these oscillations needs to be limited to a …
View article: A New Orbit Feedforward Table Generation Method for Insertion Devices
A New Orbit Feedforward Table Generation Method for Insertion Devices Open
A new method of orbit feedforward (FF) table generation for insertion devices (IDs) is proposed. The main purpose of the orbit FF table is to suppress orbit disturbance around a storage ring, caused by the gap/phase motion of an ID. A conv…
View article: Connecting Gas-Scattering Lifetime and Ion Instabilities
Connecting Gas-Scattering Lifetime and Ion Instabilities Open
Recently there is a renewed interest in fast ion instability (FII) which is of concern for future low-emittance electron storage rings, such as MBA light sources and colliders, i.e. eRHIC. While analytical theories and numerical codes exis…
View article: Investigation on Mysterious Long-Term Orbit Drift at NSLS-II
Investigation on Mysterious Long-Term Orbit Drift at NSLS-II Open
Over a few months in 2018, we observed occasional episodes of relatively quick accumulation of correction strengths for the fast correctors (used by the fast orbit feedback) near Cell 4 (C04) region at NSLS-II Storage Ring. We immediately …
View article: Beam-induced power in HEX SCW
Beam-induced power in HEX SCW Open
A superconducting wiggler (SCW) is planned to be installed in NSLS-II for HEX beamline. Interaction of the electron beam with the resistive-wall impedance of the low-gap SCW liner and with the geometric impedance of the transition sections…
View article: Vertical Coupled Bunched-Beam Breakup Due to Resistive-Wall Wake
Vertical Coupled Bunched-Beam Breakup Due to Resistive-Wall Wake Open
We estimate in this note the magnitude of the vertical rigid coupled-bunch mode of Courant and Sessler [1] at NSLS-II. If the proposed mini gap undulators (MGUs) are operated at the room temperature, the threshold current is calculated to …
View article: Vertical Coupled Bunched-Beam Breakup Due to Resistive-Wall Wake
Vertical Coupled Bunched-Beam Breakup Due to Resistive-Wall Wake Open
We estimate in this note the magnitude of the vertical rigid coupled-bunch mode of Courant and Sessler at NSLS-II. If the proposed mini gap undulators (MGUs) are operated at the room temperature, the threshold current is calculated to be a…
View article: Effects of a long low-gap in-vacuum undulator on the impedance and beam lifetime
Effects of a long low-gap in-vacuum undulator on the impedance and beam lifetime Open
Possible installation of a long low-gap in-vacuum undulator in the NSLS-II storage ring could result in several impedance-related and beam lifetime issues. High impedance of the low-gap undulator can result in beam instabilities and beam-i…