Paper | Title | Page |
---|---|---|
MOZPLS2 | Ion Collider Precision Measurements With Different Species | 28 |
|
||
Funding: Work supported by Brookhaven Science Associates, LLC, under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Precedent to electron cooling commissioning and collisions of Gold at various energies at RHIC in 2018, the STAR experiment desired an exploration of the chiral magnetic effect in the quark gluon plasma (QGP) with an isobar run, utilizing Ruthenium and Zirconium. Colliding Zr-96 with Zr-96 and Ru-96 with Ru-96 create the same QGP but in a different magnetic field due to the different charges of the Zr (Z=40) and Ru (Z=44) ions. Since the charge difference is only 10%, the experimental program requires exacting store conditions for both ions. These systematic error concerns presented new challenges for the Collider, including frequent reconfiguration of the Collider for the different ion species, and maintaining level amounts of instantaneous and integrated luminosity between two species. Moreover, making beams of Zr-96 and Ru-96 is challenging since the natural abundances of these isotopes are low. Creating viable enriched source material for Zr-96 required assistance processing from RIKEN, while Ru-96 was provided by a new enrichment facility under commissioning at Oak Ridge National Laboratory. |
||
![]() |
Slides MOZPLS2 [4.758 MB] | |
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOZPLS2 | |
About • | paper received ※ 11 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
MOPMP050 | Performance of CeC PoP Accelerator | 559 |
|
||
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Coherent electron cooling experiment is aimed for demonstration of the proof-of-principle demonstration of reduction energy spread of a single hadron bunch circulating in RHIC. The electron beam should have the required parameters and its orbit and energy should be matched to the hadron beam. In this paper we present the achieved electron beam parameters including emittance, energy spread, and other critical indicators. The operational issues as well as future plans are also discussed. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP050 | |
About • | paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
MOPRB072 | eRHIC in Electron-Ion Operation | 738 |
|
||
Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. The design effort for the electron-ion collider eRHIC has concentrated on electron-proton collisions at the highest luminosities over the widest possible energy range. The present design also provides for electron-nucleon peak luminosities of up to 4.7·1033 cm-2s−1 with strong hadron cooling, and up to 1.7·1033 cm-2s−1 with stochastic cooling. Here we discuss the performance limitations and design choices for electron-ion collisions that are different from the electron-proton collisions. These include the ion bunch preparation in the injector chain, acceleration and intrabeam scattering in the hadron ring, path length adjustment and synchronization with the electron ring, stochastic cooling upgrades, machine protection upgrades, and operation with polarized electron beams colliding with either unpolarized ion beams or polarized He-3. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB072 | |
About • | paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
MOPRB085 | First Results from Commissioning of Low Energy RHIC Electron Cooler (LEReC) | 769 |
|
||
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The brand new non-magnetized bunched beam electron cooler (LEReC) [1] has been built to provide luminosity improvement for Beam Energy Scan II (BES-II) physics program at the Relativistic Heavy Ion Collider (RHIC) BES-II [2]. The LEReC accelerator includes a photocathode DC gun, a laser system, a photocathode delivery system, magnets, beam diagnostics, a SRF booster cavity, and a set of Normal Conducting RF cavities to provide sufficient flexibility to tune the beam in the longitudinal phase space. This high-current high-power accelerator was successfully commissioned in period of March -September 2018. Beam quality suitable for cooling has been demonstrated. In this paper we discuss beam commissioning results and experience learned during commissioning. [1] A. Fedotov et al., ’Status of bunched beam electron cooler LEReC’ in these proceedings. [2] C.Liu et al., ’Improving luminosity of Beam Energy Scan II at RHIC’ in these proceedings. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB085 | |
About • | paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
TUPGW102 | CBETA - Novel Superconducting ERL | 1651 |
|
||
Funding: New York State Research&Development Authority - NYSERDA agreement number 102192 We are successfully commissioning a unique Cornell University and Brookhaven National Laboratory Electron Recovery Linac (ERL) Test Accelerator ’CBETA’ [1]. The ERL has four accelerating passes through the supercon-ducting linac with a single Fixed Field Alternating Linear Gradient (FFA-LG) return beam line built of the Halbach type permanent magnets. CBETA ERL accelerates elec-trons from 42 MeV to 150 MeV, with the 6 MeV injec-tor. The novelties are that four electron beams, with ener-gies of 42, 78, 114, and 150 MeV, are merged by spreader beam lines into a single arc FFA-LG beam line. The elec-tron beams from the Main Linac Cryomodule (MLC) pass through the FFA-LG arc and are adiabatically merged into a single straight line. From the straight section the beams are brought back to the MLC the same way. This is the first 4 pass superconducting ERL and the first single permanent magnet return line. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW102 | |
About • | paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
TUPTS078 | Coherent Electron Cooling (CeC) Experiment at RHIC: Status and Plans | 2101 |
|
||
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy and NSF Grant No. PHY-141525 We will present currents status of the CeC experiment at RHIC and discuss plans for future. Special focus will be given to unexpected experimental results obtained during RHIC Run 18 and discovery of a previously unknown type of microwave instability. We called this new phenomenon micro-bunching Plasma Cascade Instability (PCI). Our plan for future experiments includes suppressing this instability in the CeC accelerator and using it as a broad-band amplifier in the CeC system. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS078 | |
About • | paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
TUPTS101 | Bi-Alkali Antimonide Photocathodes for LEReC DC Gun | 2154 |
|
||
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Low Energy RHIC electron cooling (LEReC) is a bunched electron cooler at RHIC. The Bi-alkali photocathodes are chosen as electron source due to its long lifetime and high QE at visible wavelength. Because the DC gun needs to produce 24/7 beams over several months, cathode production system and multiple cathodes transferring systems are designed, commissioned and in operation. In this report, we will describe our photocathodes production and discuss the cathode’s performance from cathode growth system to the DC gun. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS101 | |
About • | paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
TUPTS109 | Status of AC Dipole Project at Rhic Injectors for Polarized 3He, Update | 2177 |
|
||
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. An ac dipole will be used for the efficient transport of polarized 3He in the AGS Booster as it is accelerated to |Gγ|=10.5. The ac dipole introduces a coherent vertical beam oscillation which allows preservation of polarization through the two intrinsic resonances Gγ=12-νy and Gγ=6+νy resonances, by full spin flipping. The AGS Booster ac dipole will be tested with protons crossing the Gγ=0+νy intrinsic resonance, which has ac dipole requirements similar to polarized 3He crossing the Gγ=12-νy resonance, providing a convenient proof of principle. This paper gives a status of the project. |
||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS109 | |
About • | paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
THPTS088 | CBETA Permanent Magnet Production Run | 4318 |
|
||
214 neodymium permanent magnets have been manufactured for the return loop of the CBETA multi-turn ERL being built at Cornell University. There are 5 types of quadrupole and combined-function gradient magnets using a variant of the circular Halbach design. These are made out of NdFeB material and glued into an aluminium housing with water channels for temperature stabilisation. The NdFeB wedges and magnet construction were done by outside companies, while the final "tuning" using inserts containing 64 iron wires per magnet was done at BNL over a period of about 6 months. Average relative field errors of 2.3·10-4 were achieved on the beam region. The magnet strengths vary by type but are of order 10T/m for quadrupole component and up to 0.3T for the dipole. This paper reports on the field quality and timeline achieved in this production process. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS088 | |
About • | paper received ※ 11 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |