Charles Hetzel
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View article: Simulation and measurement of beam-induced heating of ceramic vacuum chambers
Simulation and measurement of beam-induced heating of ceramic vacuum chambers Open
In this article, we summarize recent theoretical and experimental studies of the impedance and beam-induced heating of titanium-coated ceramic vacuum chambers used in the NSLS-II injection kickers. The impedance was calculated using the fi…
View article: Progress on the design of the interaction region of the Electron-Ion Collider EIC
Progress on the design of the interaction region of the Electron-Ion Collider EIC Open
We present an update on the design of the Interaction Region (IR) for the the Electron Ion Collider (EIC) being built at Brookhaven National Laboratory (BNL). The EIC will collide high energy and highly polarized hadron and electron beams …
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: Design of the NSLS-II Top-Off Safety System
Design of the NSLS-II Top-Off Safety System Open
The NSLS-II accelerators finished commissioning in the fall of 2014, with beamline commissioning underway. Part of the design for the NSLS-II is to operate in top off mode. The Top Off Safety System (TOSS) is presently being installed. In …
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: The Interaction Region of the Electron-Ion Collider EIC
The Interaction Region of the Electron-Ion Collider EIC Open
This paper presents an overview of the Interaction Region (IR) design for the planned Electron-Ion Collider (EIC) at Brookhaven National Laboratory. The IR is designed to meet the requirements of the nuclear physics community *. The IR des…
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: Conceptual Design Overview of the Electron Ion Collider Instrumentation
Conceptual Design Overview of the Electron Ion Collider Instrumentation Open
A new high-luminosity Electron Ion Collider (EIC) is being developed at Brookhaven National Laboratory (BNL). The conceptual design [1] has recently been completed. The EIC will be realized in the existing RHIC facility. In addition to imp…
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: The RCS Design Status for the Electron Ion Collider
The RCS Design Status for the Electron Ion Collider Open
The design of the Electron-Ion Collider Rapid Cycling Synchrotron (RCS) to be constructed at Brookhaven National Laboratory is advancing to meet the injection requirements for the Electron Storage Ring (ESR). Over the past year activities …
View article: Impedance Optimization of the EIC Interaction Region Vacuum Chamber
Impedance Optimization of the EIC Interaction Region Vacuum Chamber Open
The interaction region chamber has a complex geometry at the crossing location of electron and proton beam pipes. In the direction of the electron beam, the pipe is designed in a way to avoid joints with cavity characteristics. The horizon…
View article: APS-U Bellows/BPM Assembly Test in NSLS-II
APS-U Bellows/BPM Assembly Test in NSLS-II Open
We report on beam studies performed at NSLS-II to test the performance of the APS-U Bellows/BPM assembly.
View article: Investigation for In-Situ Removal of Carbon from Optical Surfaces
Investigation for In-Situ Removal of Carbon from Optical Surfaces Open
The ability to effectively clean optical surfaces of carbon to restore performance without damage is of great importance for soft x-ray beamlines. There is currently a good deal of focus on prevention and cleaning through the use of simple…
View article: eRHIC Design Overview
eRHIC Design Overview Open
The Electron-Ion Collider (EIC) is being envisioned as the next facility to be constructed by the DOE Nuclear Physics program. Brookhaven National Laboratory is proposing eRHIC, a facility based on the existing RHIC complex as a cost effec…
View article: Alternative Injection Schemes to the NSLS-II Using Nonlinear Injection Magnets
Alternative Injection Schemes to the NSLS-II Using Nonlinear Injection Magnets Open
The NSLS-II storage ring uses the standard four bump injection scheme to inject beam off axis. BESSY and MAX IV are now using a pulsed multipole magnet as an injection kicker. The injected beam sees a field off axis for injection while the…
View article: Impedance of the Flange Joints With the RF Contact Spring in NSLS-II
Impedance of the Flange Joints With the RF Contact Spring in NSLS-II Open
Since the beginning of the NSLS-II commissioning, temperature of the vacuum components has been moni-tored by the Resistance Temperature Detectors located predominantly outside of the vacuum enclosure and at-tached to the chamber body. Tem…
View article: Temperature Measurements of the NSLS-II Vacuum Components
Temperature Measurements of the NSLS-II Vacuum Components Open
This paper is dedicated to the analysis of our recent experience from ramp-up of operating current at NSLS-II from 25 mA at the end of commissioning in 2014 to 475 mA achieved in studies today. To approach the design level of the ring inte…
View article: eRHIC Electron Ring Design Status
eRHIC Electron Ring Design Status Open
For the proposed electron-ion collider eRHIC, an electron storage ring will be installed in the existing RHIC tunnel. To reach the high luminosity of up to 10³⁴ cm⁻² sec⁻¹, beam currents up to 2.5A have to be stored. Besides high luminosit…
View article: eRHIC Design Update
eRHIC Design Update Open
The future electron-ion collider (EIC) aims at an electron-proton luminosity of 10³³ to 10³⁴ cm⁻² sec⁻¹ and a center-of-mass energy range from 20 to 140 GeV. The eRHIC design has been continuously evolving over a couple of years and has re…
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: Re-Evaluation of Active Interlock Envelopes Considering Insertion Device Correction Coils
Re-Evaluation of Active Interlock Envelopes Considering Insertion Device Correction Coils Open
The Active Interlock (AI) is a system that ensures that the beam position and angle through the NSLS-II storage ring is located so that the machine apertures that may be struck by synchrotron radiation are not exposed to high power beam wh…
View article: Impedance Modeling for eRHIC
Impedance Modeling for eRHIC Open
The impedance budget for the eRHIC project is discussed at its earlier stage of development. As a first step, with the eRHIC lattice and beam parameters , we use the geometric impedances of the vacuum chamber components simulated for the N…
View article: Refurbishment of a used in-vacuum undulator from the National Synchrotron Light Source for the National Synchrotron Light Source-II ring
Refurbishment of a used in-vacuum undulator from the National Synchrotron Light Source for the National Synchrotron Light Source-II ring Open
The National Synchrotron Light Source (NSLS) ceased operation in September 2014 and was succeeded by NSLS-II. There were four in-vacuum undulators (IVUs) in operation at NSLS. The most recently constructed IVU for NSLS was the mini-gap und…
View article: National Synchrotron Light Source II storage ring vacuum systems
National Synchrotron Light Source II storage ring vacuum systems Open
The National Synchrotron Light Source II, completed in 2014, is a 3-GeV synchrotron radiation (SR) facility at Brookhaven National Laboratory and has been in steady operation since. With a design electron current of 500 mA and subnanometer…
View article: Commissioning of Active Interlock System for NSLS II Storage Ring
Commissioning of Active Interlock System for NSLS II Storage Ring Open
The NSLS-II storage ring is protected from possible damage from insertion devices (IDs) synchrotron radiation by a dedicated active interlock system (AIS). It monitors electron beam position and angle and triggers beam drop if beam orbit e…