Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Cavity (5)
- Niobium (4)
- Plasma (4)
- Beam dynamics (3)
- Electron (3)
-
- HOM (3)
- Lorentz force detuning (3)
- Cancer (2)
- Cavity preparation (2)
- Crabbing cavity (2)
- Damping (2)
- Dipole (2)
- Electron gun (2)
- LHC luminosity (2)
- Particle accelerators (2)
- Plasma simulation (2)
- Quadrupoles (2)
- Solenoid (2)
- Superconductivity (2)
- 12 GeV Beam Line (1)
- 14 TeV beam operation (1)
- 14 TeV proton beam collision (1)
- Accelerating electric field (1)
- Accelerators and industry (1)
- Affinity (1)
- Alcator-C tokamak (1)
- Antennas in plasma (1)
- Aperture geometry (1)
- Atmospheric pressure (1)
- Baseline design (1)
- Publication Year
- Publication
- Publication Type
Articles 1 - 30 of 46
Full-Text Articles in Plasma and Beam Physics
Quantum Efficiency Enhancement In Simulated Nanostructured Negative Electron Affinity Gaas Photocathodes, Md Aziz Ar Rahman, Shukui Zhang, Hani E. Elsayed-Ali
Quantum Efficiency Enhancement In Simulated Nanostructured Negative Electron Affinity Gaas Photocathodes, Md Aziz Ar Rahman, Shukui Zhang, Hani E. Elsayed-Ali
Physics Faculty Publications
Nanostructured negative electron affinity GaAs photocathodes for a polarized electron source are studied using finite difference time domain optical simulation. The structures studied are nanosquare columns, truncated nanocones, and truncated nanopyramids. Mie-type resonances in the 700–800 nm waveband, suitable for generation of polarized electrons, are identified. At resonance wavelengths, the nanostructures can absorb up to 99% of the incident light. For nanosquare columns and truncated nanocones, the maximum quantum efficiency (QE) at 780 nm obtained from simulation is 27%, whereas for simulated nanopyramids, the QE is ∼21%. The high photocathode quantum efficiency is due to the shift of Mie resonance …
Direct Current Magnetic Hall Probe Technique For Measurement Of Field Penetration In Thin Film Superconductors For Superconducting Radio Frequency Resonators, Iresha Harshani Senevirathne, Alex Gurevich, Jean Delayen
Direct Current Magnetic Hall Probe Technique For Measurement Of Field Penetration In Thin Film Superconductors For Superconducting Radio Frequency Resonators, Iresha Harshani Senevirathne, Alex Gurevich, Jean Delayen
Physics Faculty Publications
Superconducting Radio Frequency (SRF) cavities used in particle accelerators are typically formed from or coated with superconducting materials. Currently, high purity niobium is the material of choice for SRF cavities that have been optimized to operate near their theoretical field limits. This brings about the need for significant R & D efforts to develop next generation superconducting materials that could outperform Nb and keep up with the demands of new accelerator facilities. To achieve high quality factors and accelerating gradients, the cavity material should be able to remain in the superconducting Meissner state under a high RF magnetic field without …
Beamline For E-Beam Processing At Uitf, G. Ciovati, C. Bott, S. Gregory, F. Hannon, Xi Li, M. Mccaughan, R. Pearce, M. Poelker, H. Vennekate
Beamline For E-Beam Processing At Uitf, G. Ciovati, C. Bott, S. Gregory, F. Hannon, Xi Li, M. Mccaughan, R. Pearce, M. Poelker, H. Vennekate
Electrical & Computer Engineering Faculty Publications
No abstract provided.
A Proposed Beam-Beam Test Facility Combine, E. Nissen, Geoffrey Krafft, Jean Delayen
A Proposed Beam-Beam Test Facility Combine, E. Nissen, Geoffrey Krafft, Jean Delayen
Physics Faculty Publications
The COmpact Machine for Beam-beam Interactions in Non-Equilibrium systems (COMBINE) is a proposed, dedicated, beam-beam test facility. The base design would make use of a pair of identical octagonal rings (2.5 meters per side) one rotated 180 degrees from the other, meeting at their common interaction point. These would be fed by an electron gun producing up to 125 keV electrons. The low energy will allow for beam-beam tune shifts commensurate with existing colliders, some linac-ring type systems, and will also allow for an exploration of the predicted effects of gear-changing, which would be performed using a variable pathlength scheme. …
Evidence Of Increased Radio-Frequency Losses In Cavities From The Fundamental Power Coupler Cold Window, Frank Marhauser, Gianluigi Ciovati
Evidence Of Increased Radio-Frequency Losses In Cavities From The Fundamental Power Coupler Cold Window, Frank Marhauser, Gianluigi Ciovati
Physics Faculty Publications
High radio-frequency (rf) losses measured for cavities in original Continuous Electron Beam Accelerator Facility (CEBAF) cryomodules, compared to the losses measured in single-cavity tests, have been a long-standing issue related to their performance. We summarize experimental evidence of increased rf losses in CEBAF cavities arising from the fundamental power coupler cold window and waveguide, respectively. Cryogenic rf tests were done on cavities tested in vertical cryostats as well as inside cryomodules in the accelerator tunnel. The cold window metallization losses were assessed by combining numerical results with measured data obtained with an existing cryogenic waveguide resonator setup. The results showed …
The Concept And Applications Of A Dual Energy Storage Ring, Bhawin Dital, Andrew Hutton, Geoffrey Krafft, Fanglei Lin, Vasiliy Morozov, Yuhong Zhang
The Concept And Applications Of A Dual Energy Storage Ring, Bhawin Dital, Andrew Hutton, Geoffrey Krafft, Fanglei Lin, Vasiliy Morozov, Yuhong Zhang
Physics Faculty Publications
A dual energy electron storage ring configuration is initially proposed as an electron cooler to cool the ion beam in a collider. It consists of two energy loops, the electron beam in the high energy loop undergoes the synchrotron radiation damping to obtain the desired beam property and the beam in the low energy loop is for cooling of the ion beam. The two different energy loops are connected by an energy recovery linac. A lattice design of such a dual energy storage ring has been completed and beam stability conditions are established. We performed numerical simulations to demonstrate the …
Instrument Design Optimization With Computational Methods, Michael H. Moore
Instrument Design Optimization With Computational Methods, Michael H. Moore
Physics Theses & Dissertations
Using Finite Element Analysis to approximate the solution of differential equations, two different instruments in experimental Hall C at the Thomas Jefferson National Accelerator Facility are analyzed. The time dependence of density fluctuations from the liquid hydrogen (LH2) target used in the Qweak experiment (2011-2012) are studied with Computational Fluid Dynamics (CFD) and the simulation results compared to data from the experiment. The 2.5 kW liquid hydrogen target was the highest power LH2 target in the world and the first to be designed with CFD at Jefferson Lab. The first complete magnetic field simulation of the Super High Momentum …
Aluminum Multicharged Ion Generation From Femtosecond Laser Plasma, Md. Haider A. Shaim, Frederick Guy Wilson, Hani E. Elsayed-Ali
Aluminum Multicharged Ion Generation From Femtosecond Laser Plasma, Md. Haider A. Shaim, Frederick Guy Wilson, Hani E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
Aluminum multicharged ion generation from femtosecond laser ablation is studied. A Ti:sapphire laser (wavelength 800 nm, pulse width ∼100 fs, and maximum laser fluence of 7.6 J/cm2) is used. Ion yield and energy distribution of each charge state are measured. A linear relationship between the ion charge state and the equivalent acceleration energy of the individual ion species is observed and is attributed to the presence of an electric field within the plasma-vacuum boundary that accelerates the ions. The ion energy distribution follows a shifted Coulomb-Boltzmann distribution. For Al1+ and Al2+, the ion energy distributions …
High Average Brilliance Compact Inverse Compton Light Source, K. Deitrick, J. R. Delayen, G. A. Krafft
High Average Brilliance Compact Inverse Compton Light Source, K. Deitrick, J. R. Delayen, G. A. Krafft
Physics Faculty Publications
There exists an increasing demand for compact Inverse Compton Light Sources (ICLS) capable of producing substantial fluxes of narrow-band X-rays. While multiple design proposals have been made, compared to typical bremsstrahlung sources, most of these have comparable fluxes and improve on the brilliance within a 0.1% bandwidth by only a few orders of magnitude. By applying cw superconducting rf beam acceleration and rf focusing to produce a beam of small emittance and magnetic focusing to produce a small spot size on the order of a few microns at collision, the source presented here provides a 12 keV X-ray beam which …
Development And Testing Of A 325 Mhz Β0= 0.82 Single-Spoke Cavity, C. S. Hopper, Hyekyoung Park, J. R. Delayen
Development And Testing Of A 325 Mhz Β0= 0.82 Single-Spoke Cavity, C. S. Hopper, Hyekyoung Park, J. R. Delayen
Physics Faculty Publications
A single-spoke cavity operating at 325 MHz with geometric beta of 0.82 has been developed and tested. Initial results* showed high levels of field emission which limited the achievable gradient. Several rounds of helium processing significantly improved the cavity performance. Here we discuss the development process and report on the improved results.
Crab Cavity And Cryomodule Development For Hl-Lhc, F. Carra, A. A. Carvalho, K. Artoos, S. Atieh, I. A. Santillana, S. Belomestnykh, A. Boucherie, J. P. Brachet, K. Brodzinski, G. Burt, S. U. De Silva, J. R. Delayen, R. Olave, H. Park
Crab Cavity And Cryomodule Development For Hl-Lhc, F. Carra, A. A. Carvalho, K. Artoos, S. Atieh, I. A. Santillana, S. Belomestnykh, A. Boucherie, J. P. Brachet, K. Brodzinski, G. Burt, S. U. De Silva, J. R. Delayen, R. Olave, H. Park
Physics Faculty Publications
The HL-LHC project aims at increasing the LHC luminosity by a factor 10 beyond the design value. The installation of a set of RF Crab Cavities to increase bunch crossing angle is one of the key upgrades of the program. Two concepts, Double Quarter Wave (DQW) and RF Dipole (RFD) have been proposed and are being produced in parallel for test in the SPS beam before the next long shutdown of CERN accelerator’s complex. In the retained concept, two cavities are hosted in one single cryomodule, providing thermal insulation and interfacing with RF coupling, tuning, cryogenics and beam vacuum. This …
Design Of Dressed Crab Cavities For The Hl-Lhc Upgrade, C. Zanoni, K. Artoos, S. Atieh, I. Aviles-Santillana, S. Belomestnykh, I. Ben-Zvi, J.P. Brachet, G. Burt, R. Calaga, O. Captina, S. U. De Silva, J. R. Delayen, A. May, K. Marinov, R. Olave, H. Park, N. Templeton
Design Of Dressed Crab Cavities For The Hl-Lhc Upgrade, C. Zanoni, K. Artoos, S. Atieh, I. Aviles-Santillana, S. Belomestnykh, I. Ben-Zvi, J.P. Brachet, G. Burt, R. Calaga, O. Captina, S. U. De Silva, J. R. Delayen, A. May, K. Marinov, R. Olave, H. Park, N. Templeton
Physics Faculty Publications
The HL-LHC upgrade relies on a set of RF crab cavities for reaching its goals. Two parallel concepts, the Double Quarter Wave (DQW) and the RF Dipole (RFD), are going through a comprehensive design process along with preparation of fabrication in view of extensive tests with beam in SPS. High Order Modes (HOM) couplers are critical in providing damping in RF cavities for operation in accelerators. HOM prototyping and fabrication have recently started at CERN. In this paper, an overview of the final geometry is provided along with an insight in the mechanical and thermal analyses performed to validate the …
Performance Evaluation Of Hl-Lhc Crab Cavity Prototypes In A Cern Vertical Test Cryostat, K. G. Hernández-Chahín, A. Macpherson, C. Jarrige, M. Navarro-Tapia, R. Torres Sánchez, G. Burt, A. Tutte, S. U. De Silva
Performance Evaluation Of Hl-Lhc Crab Cavity Prototypes In A Cern Vertical Test Cryostat, K. G. Hernández-Chahín, A. Macpherson, C. Jarrige, M. Navarro-Tapia, R. Torres Sánchez, G. Burt, A. Tutte, S. U. De Silva
Physics Faculty Publications
Three proof-of-principle compact crab cavity designs have been fabricated in bulk niobium and cold tested at their home labs, as a first validation step towards the High Luminosity LHC project. As a cross check, all three bare cavities have been retested at CERN, in order to cross check their performance, and cross-calibrate the CERN SRF cold test facilities. While achievable transverse deflecting voltage is the key performance indicator, secondary performance aspects derived from multiple cavity monitoring systems are also discussed. Temperature mapping profiles, quench detection, material properties, and trapped magnetic flux effects have been assessed, and the influence on performance …
Superconducting Cavity For The Measurements Of Frequency, Temperature, Rf Field Dependence Of The Surface Resistance, Hyekyoung Park, S.U. De Silva, J. R. Delayen
Superconducting Cavity For The Measurements Of Frequency, Temperature, Rf Field Dependence Of The Surface Resistance, Hyekyoung Park, S.U. De Silva, J. R. Delayen
Physics Faculty Publications
In order to better understand the contributions of the various physical processes to the surface resistance of superconductors the ODU Center for Accelerator Science is developing a half-wave resonator capable of operating between 325 MHz and 1.3 GHz. This will allow the measurement of the temperature and rf field dependence of the surface resistance on the same surface over the range of frequency of interest for particle accelerators and identify the various sources of power dissipation.
Analysis Of A 750 Mhz Srf Dipole Cavity, Alejandro Castilla, J. R. Delayen
Analysis Of A 750 Mhz Srf Dipole Cavity, Alejandro Castilla, J. R. Delayen
Physics Faculty Publications
There is a growing interest in using rf transverse deflecting structures for a plethora of applications in the current and future high performance colliders. In this paper, we present the results of a proof of principle superconducting rf dipole, designed as a prototype for a 750 MHz crabbing corrector for the Medium Energy Electron-Ion Collider (MEIC), which has been successfully tested at 4.2 K and 2 K at the Jefferson Lab’s Vertical Testing Area (VTA). The analysis of its rf performance during cryogenic testing, along with Helium pressure sensitivity, Lorentz detuning, surface resistance, and multipacting processing analysis are presented in …
Experiment And Results On Plasma Etching Of Srf Cavities, J. Upadhyay, Do Im, J. Peshl, S. Popovic, L. Vuskovic, A. -M. Valente-Feliciano, L. Phillips
Experiment And Results On Plasma Etching Of Srf Cavities, J. Upadhyay, Do Im, J. Peshl, S. Popovic, L. Vuskovic, A. -M. Valente-Feliciano, L. Phillips
Physics Faculty Publications
The inner surfaces of SRF cavities are currently chemically treated (etched or electro polished) to achieve the state of the art RF performance. We designed an apparatus and developed a method for plasma etching of the inner surface for SRF cavities. The process parameters (pressure, power, gas concentration, diameter and shape of the inner electrode, temperature and positive dc bias at inner electrode) are optimized for cylindrical geometry. The etch rate non-uniformity has been overcome by simultaneous translation of the gas point-of-entry and the inner electrode during the processing. A single cell SRF cavity has been centrifugally barrel polished, chemically …
Design And Prototyping Of A 400 Mhz Rf-Dipole Crabbing Cavity For The Lhc High-Luminosity Upgrade, S. U. De Silva, J. R. Delayen, H. Park, Z. Li, T. H. Nicol
Design And Prototyping Of A 400 Mhz Rf-Dipole Crabbing Cavity For The Lhc High-Luminosity Upgrade, S. U. De Silva, J. R. Delayen, H. Park, Z. Li, T. H. Nicol
Physics Faculty Publications
LHC High Luminosity Upgrade is in need of two crabbing systems that deflects the beam in both horizontal and vertical planes. The 400 MHz rf-dipole crabbing cavity system is capable of crabbing the proton beam in both planes. At present we are focusing our efforts on a complete crabbing system in the horizontal plane. Prior to LHC installation the crabbing system will be installed for beam test at SPS. The crabbing system consists of two rf-dipole cavities in the cryomodule. This paper discusses the electromagnetic design and mechanical properties of the rf-dipole crabbing system for SPS beam test.
Imperfection And Tolerance Analysis Of Hom Couplers For Odu/Slac 400 Mhz Crabbing Cavity, S. U. De Silva, R. G. Olave, H. Park, J. R. Delayen, Z. Li
Imperfection And Tolerance Analysis Of Hom Couplers For Odu/Slac 400 Mhz Crabbing Cavity, S. U. De Silva, R. G. Olave, H. Park, J. R. Delayen, Z. Li
Physics Faculty Publications
In preparation for the LHC High Luminosity upgrade, a 400 MHz crab cavity has been developed jointly at ODU/SLAC, including two higher order mode couplers designed to dampen the wakefields in order to comply with the impedance budget specified for the LHC system. During fabrication, assembly, and processing of the couplers, a number of imperfections may arise that could modify the higher order mode spectrum and the associated impedance for each mode. We present here a detailed study of the imperfections of the horizontal- and vertical- HOM couplers, and the associated allowed tolerances for manufacture, assembly and processing.
Beam Dynamics Studies Of 499 Mhz Superconducting Rf-Dipole Deflecting Cavity System, S. U. De Silva, K. E. Deitrick, H. Park, J. R. Delayen
Beam Dynamics Studies Of 499 Mhz Superconducting Rf-Dipole Deflecting Cavity System, S. U. De Silva, K. E. Deitrick, H. Park, J. R. Delayen
Physics Faculty Publications
A 499 MHz deflecting cavity has been designed as a three-way beam spreader to separate an electron beam into 3 beams. The rf tests carried out on the superconducting rf-dipole cavity have demonstrated that a transverse voltage of 4.2 MV can be achieved with a single cavity. This paper discusses the beam dynamics on a deflecting structure operating in continuous-wave mode with a relativistic beam. The study includes the analysis on emittance growth, energy spread, and change in bunch size including effects due to field non-uniformities.
Progress On A Compact Accelerator Design For A Compton Light Source, K. Deitrick, J. R. Delayen, B.R.P. Gamage, Geoffrey A. Krafft, T. Satogata
Progress On A Compact Accelerator Design For A Compton Light Source, K. Deitrick, J. R. Delayen, B.R.P. Gamage, Geoffrey A. Krafft, T. Satogata
Physics Faculty Publications
A compact Compton light source using an electron linear accelerator is in design at the Center for Accelerator Science at Old Dominion University and Jefferson Lab. We report on the current design, including beam properties through the entire system based on a full end-to-end simulation, compare current specifications to design goals, and target areas for improvement.
Peppo: Using A Polarized Electron Beam To Produce Polarized Positrons, A. Adeyemi, G.L Gueye, P.A. Adderly, M. L. Stutzman, M. M. Ali, H. Areti, J. F. Benesch, L. S. Cardman, J. Clark, S. Covert, S. Golge, C. Hyde
Peppo: Using A Polarized Electron Beam To Produce Polarized Positrons, A. Adeyemi, G.L Gueye, P.A. Adderly, M. L. Stutzman, M. M. Ali, H. Areti, J. F. Benesch, L. S. Cardman, J. Clark, S. Covert, S. Golge, C. Hyde
Physics Faculty Publications
An experiment demonstrating a new method for producing polarized positrons has been performed at the CEBAF accelerator at Jefferson Laboratory. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e+/e− pairs originating from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a 1.0 mm tungsten pair-production target. This paper describes preliminary results of measurements using an 8.2 MeV/c electron beam with polarization 84% to generate positrons in the range of 3.1 to 6.2 MeV/c with polarization as high as ∼80%.
Effects Of Crab Cavities Multipole Content In An Electron-Ion Collider, A. Castilla, V. S. Morozov, T. Satogata, J. R. Delayen
Effects Of Crab Cavities Multipole Content In An Electron-Ion Collider, A. Castilla, V. S. Morozov, T. Satogata, J. R. Delayen
Physics Faculty Publications
The impact on the beam dynamics of the Medium Energy Electron-Ion Colider (MEIC) due to the multipole content of the 750 MHz crab cavity was studied using thin multipole elements for 6D phase space particle tracking in ELEGANT. Target values of the sextupole component for the cavity’s field expansion were used to perform preliminary studies on the proton beam stability when compared to the case of pure dipole content of the rf kicks. Finally, important effects on the beam sizes due to non-linear components of the crab cavities’ fields were identified and some criteria for their future study were proposed.
Engineering Design And Prototype Fabrication Of Hom Couplers For Hl-Lhc Crab Cavities, C. Zanoni, S. Atieh, I. Aviles Santillana, S. Belomestnykh, G. Burt, R. Calaga, S. U. De Silva, J. R. Delayen, R. Olave, H. Park
Engineering Design And Prototype Fabrication Of Hom Couplers For Hl-Lhc Crab Cavities, C. Zanoni, S. Atieh, I. Aviles Santillana, S. Belomestnykh, G. Burt, R. Calaga, S. U. De Silva, J. R. Delayen, R. Olave, H. Park
Physics Faculty Publications
The High-Luminosity upgrade for the LHC relies on a set of RF Crab Cavities for reaching its goals. Two parallel concepts, the Double Quarter Wave (DQW) and the RF Dipole (RFD), are going through a comprehensive design process along with preparation of fabrication in view of extensive tests with beam in SPS. High Order Modes (HOM) couplers are critical in providing damping in RF cavities for operation in accelerators. HOM prototyping and fabrication have recently started at CERN. In this paper, an overview of the final shape is provided along with an insight in the mechanical and thermal analyses performed …
Electromagnetic Design Of 400 Mhz Rf-Dipole Crabbing Cavity For Lhc High Luminosity Upgrade, S.U. De Silva, H. Park, J. R. Delayen, Z. Li
Electromagnetic Design Of 400 Mhz Rf-Dipole Crabbing Cavity For Lhc High Luminosity Upgrade, S.U. De Silva, H. Park, J. R. Delayen, Z. Li
Physics Faculty Publications
The beam crabbing proposed for the LHC High Luminosity Upgrade requires two crabbing systems operating in both horizontal and vertical planes. In addition, the crabbing cavity design needs to meet strict dimensional constraints and functional specifications of the cavities. This paper presents the detailed electromagnetic design including em properties, multipole analysis, multipacting levels of the 400 MHz rf-dipole crabbing cavity.
Secondary Electron Yield Of Electron Beam Welded Areas Of Srf Cavities, M. Basovic, S. Popovic, M. Tomovic, L. Vuskovic, A. Samolov, F. Cuckov
Secondary Electron Yield Of Electron Beam Welded Areas Of Srf Cavities, M. Basovic, S. Popovic, M. Tomovic, L. Vuskovic, A. Samolov, F. Cuckov
Physics Faculty Publications
Secondary Electron Emission (SEE) is a phenomenon that contributes to the total electron activity inside the Superconducting Radiofrequency (SRF) cavities during the accelerator operation. SEE is highly dependent on the state of the surface. During electron beam welding process, significant amount of heat is introduced into the material causing the microstructure change of Niobium (Nb). Currently, all simulation codes for field emission and multipacting are treating the inside of the cavity as a uniform, homogeneous surface. Due to its complex shape and fabricating procedure, and the sensitivity of the SEE on the surface state, it would be interesting to see …
Progress On The Design Of The Polarized Medium Energy Electron Ion Collider At Jlab, F. Lin, S. A. Bogacz, P. D. Brindza, A Camsonne, E. Daly, Y. S. Derbenev, D. Douglas, R. Ent, D. Gaskell, R. L. Geng, A. Castilla, J. R. Delayen, C. E. Hyde, K. Park
Progress On The Design Of The Polarized Medium Energy Electron Ion Collider At Jlab, F. Lin, S. A. Bogacz, P. D. Brindza, A Camsonne, E. Daly, Y. S. Derbenev, D. Douglas, R. Ent, D. Gaskell, R. L. Geng, A. Castilla, J. R. Delayen, C. E. Hyde, K. Park
Physics Faculty Publications
The Medium-energy Electron Ion Collider (MEIC) at JLab is designed to provide high luminosity and high polarization needed to reach new frontiers in the exploration of nuclear structure. The luminosity, exceeding 1033 cm-2s−1 in a broad range of the center-of-mass (CM) energy and maximum luminosity above 1034 cm-2s−1, is achieved by high-rate collisions of short small-emittance low-charge bunches made possible by high-energy electron cooling of the ion beam and synchrotron radiation damping of the electron beam. The polarization of light ion species (p, d, 3He) can be easily preserved and …
Evaluation Of The Effects Of A Plasma Activated Medium On Cancer Cells, S. Mohades, M. Laroussi, J. Sears, N. Barekzi, H. Razavi
Evaluation Of The Effects Of A Plasma Activated Medium On Cancer Cells, S. Mohades, M. Laroussi, J. Sears, N. Barekzi, H. Razavi
Electrical & Computer Engineering Faculty Publications
The interaction of low temperature plasma with liquids is a relevant topic of study to the field of plasma medicine. This is because cells and tissues are normally surrounded or covered by biological fluids. Therefore, the chemistry induced by the plasma in the aqueous state becomes crucial and usually dictates the biological outcomes. This process became even more important after the discovery that plasma activated media can be useful in killing various cancer cell lines. Here, we report on the measurements of concentrations of hydrogen peroxide, a species known to have strong biological effects, produced by application of plasma to …
Higher Order Mode Damping In Superconducting Spoke Cavities, C. S. Hopper, J. R. Delayen
Higher Order Mode Damping In Superconducting Spoke Cavities, C. S. Hopper, J. R. Delayen
Physics Faculty Publications
Parasitic higher order modes (HOMs) can be severely detrimental to the performance of superconducting cavities. For this reason, the mode spectrum and beam coupling strength must be examined in detail to determine which modes must be damped. One advantage of the spoke cavity geometry is that couplers can be placed on the outer body of the cavity rather than in the beam line space. We present an overview of the HOM properties of spoke cavities and methods for suppressing the most harmful ones.
Employing Twin Crabbing Cavities To Address Variable Transverse Coupling Of Beams In The Meic, A. Castilla, V. S. Morozov, T. Satogata, J. R. Delayen
Employing Twin Crabbing Cavities To Address Variable Transverse Coupling Of Beams In The Meic, A. Castilla, V. S. Morozov, T. Satogata, J. R. Delayen
Physics Faculty Publications
The design strategy of the Medium Energy Electron-Ion Collider (MEIC) at Jefferson Lab contemplates both matching of the emittance aspect ratios and a 50 mrad crossing angle along with crab crossing scheme for both electron and ion beams over the energy range (√s=20-70 GeV) to achieve high luminosities at the interaction points (IPs). However, the desired locations for placing the crabbing cavities may include regions where the transverse degrees of freedom of the beams are coupled with variable coupling strength that depends on the collider rings’ magnetic elements (solenoids and skew quadrupoles). In this work we explore the feasibility of …
Progress On The Interaction Region Design And Detector Integration At Jlab's Meic, V. S. Morozov, P. Brindza, A. Camsonne, Ya S. Derbenev, R. Ent, D. Gaskell, F. Lin, P. Nadel-Turonski, M. Ungaro, Y. Zhang, C. E. Hyde, K. Park, M. Sullivan, Z. W. Zhao
Progress On The Interaction Region Design And Detector Integration At Jlab's Meic, V. S. Morozov, P. Brindza, A. Camsonne, Ya S. Derbenev, R. Ent, D. Gaskell, F. Lin, P. Nadel-Turonski, M. Ungaro, Y. Zhang, C. E. Hyde, K. Park, M. Sullivan, Z. W. Zhao
Physics Faculty Publications
One of the unique features of JLab's Medium-energy Electron-Ion Collider (MEIC) is a full-acceptance detector with a dedicated, small-angle, high-resolution detection system, capable of covering a wide range of momenta (and charge-to-mass ratios) with respect to the original ion beam to enable access to new physics. We present an interaction region design developed with close integration of the detection and beam dynamical aspects. The dynamical aspect of the design rests on a symmetry-based concept for compensation of non-linear effects. The optics and geometry have been optimized to accommodate the detection requirements and to ensure the interaction region's modularity for ease …