Design study of primary ion provider for RHIC-EBIS (open access)

Design study of primary ion provider for RHIC-EBIS

Brookhaven National Laboratory (BNL) has developed the new pre-injector system, Electron Beam Ion Source (EBIS) for Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ion beam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented.
Date: September 20, 2009
Creator: Kondo, K.; Kanesue, T.; Tamura, J. & Okamura, M.
Object Type: Article
System: The UNT Digital Library
Drift distance survey in DPIS for high current beam production (open access)

Drift distance survey in DPIS for high current beam production

In a laser ion source, plasma drift distance is one of the most important design parameters. Ion current density and beam pulse width are defined by plasma drift distance between laser target and beam extraction position. In direct plasma injection scheme (DPIS), which uses a laser ion source and Radio Frequency Quadrupole (RFQ) linac, we can apply relatively higher electric field at the beam extraction due to the unique shape of a positively biased electrode. However, when we aim at very high current acceleration like several tens of mA, we observed mismatched beam extraction conditions. We tested three different ion current at ion extraction region by changing plasma drift distance to study better extraction condition. In this experiment, C{sup 6+} beam was accelerated. We confirmed that the matching condition can be improved by controlling plasma drift distance.
Date: September 20, 2009
Creator: Kanesue,T.; Okamura, M.; Kondo, K.; Tamura, J.; Kashiwagi, H. & Zhang, Z.
Object Type: Article
System: The UNT Digital Library
HOM absorbers for ERL cryomodules at BNL (open access)

HOM absorbers for ERL cryomodules at BNL

The physics needs and technical requirements for several future accelerator projects at the Relativistic Heavy Ion Collider (RHIC) all involve electron Energy Recovery Linacs (ERL). The required high-current, high-charge operating parameters make effective higher-order-mode (HOM) damping mandatory and the development of HOM dampers for a prototypical five-cell cavity is actively pursued. An experimental five-cell niobium cavity with ferrite dampers has been constructed, and effective HOM damping has been demonstrated at room and superconducting (SC) temperatures. A novel type of ferrite damper around a ceramic break has been developed for the ERL electron gun and prototype tests are also reported. Contemplated future projects are based on assembling a chain of superconducting cavities in a common cryomodule with the dampers placed in the cold space between the cavities, imposing severe longitudinal space constraints. Various damper configurations have been studied by placing them between two five-cell copper cavities. Measured and simulated copper cavity results, external Q-values of possible dampers and fundamental mode losses are presented.
Date: September 20, 2009
Creator: Hahn, H.; Ben-Zvi, Ilan; Hammons, L. & Xu, W.
Object Type: Article
System: The UNT Digital Library
Laser plasma in a magnetic field (open access)

Laser plasma in a magnetic field

Laser Ion Source (LIS) is a candidate among various heavy ion sources. A high density plasma produced by Nd:YAG laser with drift velocity realizes high current and high charge state ion beams. In order to obtain higher charged particle ions, we had test experiments of LIS with a magnetic field by which a connement effect can make higher charged beams. We measured total current by Faraday Cup (FC) and analyzed charge distribution by Electrostatic Ion Analyzer (EIA). It is shown that the ion beam charge state is higher by a permanent magnet.
Date: September 20, 2009
Creator: Kondo,K.; Kanesue, T.; Tamura, J.; Dabrowski, R. & Okamura, M.
Object Type: Article
System: The UNT Digital Library
Low Cost, Light Weight SOlar Modules Based on Organic Photovoltaic Technology (open access)

Low Cost, Light Weight SOlar Modules Based on Organic Photovoltaic Technology

Objectives - In order to produce solar modules for rooftop applications the performance and the lifetime must be improved to 5% - 7% and >10 year life. Task 1 Stability - (1) Flexible modules are stable to 1000 hrs at 65 C/85%RH, (2) Flexible modules in glass are stable to >2000 hrs at 85 C/85%RH (no decrease in performance); (3) Adhesive + filler helps stabilize modules; and (4) Solution coatable barriers exhibit good WVTR; work in-progress. Task 2 Performance: n-type charge carriers - (1) N-type polymers could not be synthesized; and (2) More than 30 fullerene derivatives synthesized and tested, Several deep LUMO derivatives accept charge from deep LUMO polymers, higher voltage observed, Improvement in cell efficiency not observed, morphology problem. Task 3 Performance: grid electrode - (1) Exceeded flatness and roughness goals; (2) Exceeds sheet resistance goals; (3) Achieved %T goals; and (4) Performance equivalent to ITO - 2% Efficiency ( av.); work in-progress.
Date: September 20, 2009
Creator: Gaudiana, Russell; GInley, David & Birkmeyer, Robert
Object Type: Report
System: The UNT Digital Library