Difference between revisions of "Research Notes and Documents"

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[[5/24/18]] -- Completed Wiki page and uploaded some files, Reading ''Ion Bombardment of Solids''
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==Tech Notes==
  
[[5/25/18]] -- Reading ''Ion Bombardment of Solids'', completed sections 2.2-2.3
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*[[:File:Wien Filter HV Calibration.pdf | WF Calibration]] -- 5/4/18 Calibration of the UITF Wien Filter (WF) by adjusting the E-Field and B-Field to determine the velocity of the electron beam
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*[[:File:Spring2018_QEPlots.png | Spring 2018 QE vs. Charge]] & [[:File:Fall2016_QEPlots.png | Fall 2016 QE vs. Charge]] -- 5/24/18 Plots of QE vs. Charge data from the CEBAF injector. The Spring 2018 plot corresponds to when the vertical WF was at 50 degrees and the horizontal WF was off. The Fall 2016 plot is the opposite with the horizontal WF at 50 degrees and the vertical WF was off.
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*[[:File:Magnetic_field_in_front_of_photogun_idea.pdf | Magnetic field in front of photogun idea]] -- 5/25/18 An idea that I had that may solve the problem of ion back-bombardment due to ion creation downstream of the anode.
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*[[:File:Derivation_of_QE_Formula.pdf | Derivation of QE Formula]] -- 6/1/18 Derivation of the formula for photocathode QE based on electron current, laser power, and wavelength
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*[[:File:Magnetic_Mirror_Derivation_notheta.pdf | Magnetic Mirror Derivation]] - 9/19/18 Derived formulas for the criteria for ions to become trapped between two solenoids.
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*[[:File:BPM_analysis_of_electron_beam.pdf | BPM analysis of electron beam]] - 9/20/18 Derivation and plots involving the analysis of an electron beam using a beam position monitor (BPM). One can detect and identify ions in the beam based on their characteristic oscillation frequency. Derivation follows from Alex Chao's Fast Ion Instability lecture notes.
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*[[:File:Net_force_on_ion_derivation.pdf | Derivation of net force on ion]] - 10/3/18 Derivation of the net force on an ion between the biased anode and Magnetizing solenoid - should be helpful in determining the conditions for which an ion can be trapped between them.
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*[[:File:IFarm_GPT_Documentation_2.pdf | How to run GPT on the JLab farm]] - 1/18/19 A tutorial on how to use the JLab farm to run many GPT simulations at once.
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*[[:File:Electron_Ion_Momentum_Calculation_CoM.pdf | Derivation of Electron-Ion Momenta during Ionization]] - 5/20/19 Deriving the initial and final momenta of the primary electron, secondary electron, and ion during ionization, provided the target molecule is at rest. Given the initial momentum of the primary electron (based on the beam energy) and the final momentum of the secondary electron (based on the differential energy cross section), the remaining values for momenta before and after the collision can be derived.
  
[[5/30/18]] -- Reading ''Ion Bombardment of Solids'', completed sections 2.4-2.6.2
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==GTS Field Map Layout==
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*[[:File:GTS_Layout_fieldmaps.jpeg | GTS Field Map Layout]] -- 10/11/18 Plot of the electric and magnetic fields through the first 1.2m of the GTS beamline using Gnuplot. The layout includes the field maps of the gun HV, biased anode, magnetizing (gun) solenoid, and the first two lenses (focusing solenoids), as well as vertical lines indicating positions of certain beamline elements (see GTS drawing)
  
[[6/1/18]] -- Discussed ionization cross-sections, uploaded derivation of QE formula
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==July 2018 CEBAF Charge Lifetime Measurements==
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*[[:File:QE_vs_charge.png | QE vs. Charge]] -- Plot of QE vs Charge between 10:13:00 and 15:12:00 on 7/11/18
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*[[:File:Pickoff_Power_vs._Inline_Power.png | Pickoff vs Inline]] -- Plot of pickoff power (to the photocathode) vs. inline power (before power meter) to determine power correction factor
  
[[6/7/18]] -- Read articles on ionization cross sections and RGA, installed Ubuntu (finally!)
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==Ion Bombardment of Solids Notes==
  
[[6/11/18]] -- Uploaded analyzed RGA spectrum (After 2 days)
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*[[:File:Ion_Bombardment_of_Solids_Intro_and_sections_2.2-2.3.pdf | Intro and Sections 2.2-2.3]] -- Completed 5/25/18
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*[[:File:Ion_Bombardment_of_Solids_Sections_2.4-2.6.2.pdf | Sections 2.4-2.6.2]] -- Completed 5/30/18
  
[[6/14/18]] -- Uploaded Ionization Cross Sections
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==Gun Voltage vs. Distance==
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*[[:File:Voltage_vs_Distance_Line_Plot.jpeg | Voltage vs. Distance Line Plot]] -- 6/27/18 A line graph of voltage vs. distance using data from Gabriel
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*[[:File:Voltage_vs_Distance_3D_Plot.jpeg | Voltage vs. Distance 3D Plot]] -- 6/27/18 An extension of the graph above into 3D space. Apparently, the potential is symmetric about the z-axis...?
  
[[6/18/18]] -- Updated Ionization Cross Sections to include section on ionization rates
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==RGA Spectra, Ionization Cross Sections, and Ion Production Rate==
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*[[:File:RGA_Spectrum_After2days.jpeg | RGA Spectrum After 2 Days]] -- RGA Spectrum for gun chamber taken on 5/21/18 after prepping for 2 days, analyzed using gnuplot on 6/11/18. Each peak was fit using a gaussian function in order to determine the maximum and standard deviation of each peak.
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*[[:File:Ionization_Cross_Sections.pdf | Ionization Cross Sections V1]] -- 6/14/18, Updated on 6/15/18, Analysis of the RGA Spectrum "After 2 Days" (see below), a sample calculation for the ionization cross section of hydrogen gas, and a plot of ionization cross section vs. beam energy (electron kinetic energy).
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*[[:File:New_Ionization_Sections.pdf | Ionization Cross Sections V2]] -- 6/19/18 Updated document above to include section on numerical calculation of ionization rates.
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*[[:File:New_Ionization_Sections_2.pdf | Ionization Cross Sections V3]] -- 6/22/18 Updated document above to include tables of calculated values for the ion production rates of the gas species using normalized partial pressures.
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*[[:File:Ionization_Rate_vs_Voltage.pdf | Ion Production Rate vs. Beam Energy]] -- 6/25/18 Formula derivation and plot of the ionization rate of gas species found in the "After 2 Days" RGA spectrum as a function of beam energy (gun voltage).
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*[[:File:Ionization_Rate_vs_Voltage_V2.pdf | Ion Production Rate vs. Beam Energy V2]] -- 8/27/18 Updated document above. Included a section on normalizing IPR to beam current. Also changed both IPR vs. beam energy plots to log-log so that the effect of ionization cross section on IPR is clearly seen.
  
[[6/22/18]] -- Updated Ionization Cross Sections to include tables of calculated values for the ionization rates from normalized partial pressures
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==Oral Qualifier Paper and Presentation==
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*[[:File:Yoskowitz_Oral_Qualifier_Write-Up.pdf | Oral Qualifier Paper]] -- 2/27/19 Contains current ionization Theory of Ghost Beam
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*[[:File:Oral_Qualifier_Presentation.pdf | Oral Qualifier Presentation]] -- 2/27/19 Presentation on above paper
  
[[6/25/18]] -- Uploaded Ion Production Rate vs Beam Energy
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==References==
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*[[:File:LyX_List_of_references_8-24-18.pdf | References]] -- List of references in bibliography format. Updated on 9/4/18
  
[[6/27/18]] -- Uploaded Voltage vs. Distance Graphs
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[[Wiki Logbook | Go to Logbook]]
  
[[7/9/18]] -- Uploaded List of References
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[[Ghost Beam Studies | Go to Ghost Beam Studies]]
  
[[7/13/18]] -- Analyzed charge lifetime data taken at CEBAF
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[[Josh Yoskowitz | Return to Home Page]]
 
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[[7/23/18]] -- Learned GPT & C++, Calculating ion production rates, Solving problems
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[[8/6/18]] -- Still waiting on PC with GPT, continuing work in last log entry
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[[8/8/18]] -- Still waiting on PC with GPT, continuing work in last log entry
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[[8/15/18]] -- Finally have PC with GPT, continuing work in last log entry
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[[8/22/18]] -- Finally have PC with GPT, continuing work in last log entry
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[[8/27/18]] -- Uploaded log-log plot of IPR vs beam energy, continuing to read Alex Chao's Fast Ion Instability
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[[9/6/18]] -- Creating GPT simulation, writing up procedure/preliminary calculations for BPM measurement, using SCAM to introduce clearing gaps
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[[9/14/18]] -- Creating GPT simulation, writing up procedure/preliminary calculations for BPM measurement
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[[10/1/18]] -- Uploaded Magnetic Mirror derivation and BPM measurements/analysis. Creating GPT simulation of ion trap, optimizing anode and mag. solenoid.
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[[10/9/18]] -- Created series of GPT simulations of ion traps, measured beam pipe diameter, derived net force on ion
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[[10/17/18]] -- Continuing GPT simulations of ion traps...to no avail. Sooooooo….BPM measurements?
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[[11/1/18]] -- Beam measurements next week: Analyzing ionization emission (light) spectra, using a BPM to analyze ion frequencies (modulation), creating/playing with the "ghost" beam, etc.
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[[11/11/18]] -- Completed initial ghost beam testing. Will continue analysis this week using spectrometer to measure light due to ionization and a BPM to measure characteristic ion oscillation frequencies (modulations) within the electron beam.
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[[12/4/18]] -- Analyzing Ghost Beam Studies data, able to create electron/proton trap in GPT
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[[1/9/19]] -- Creating rigorous ionization theory of the ghost beam
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[[1/18/19]] -- Created documentation on how to use the JLab Farm, preliminary ideas for measuring ghost light between the anode and magnetizing solenoid for when the T-Gun is installed
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[[2/18/19]] -- Working on Oral Qualifier Paper/Presentation (on 2/27), narrowing in on thesis project, working on ionization simulation using GPT/IBSimu with Cristian and Ricardo
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[[2/26/19]] -- Oral Qualifier Presentation tomorrow, paper uploaded. Will work on Bas' ionization routine to simulate ion production for a real beam at GTS (not just a cylindrical beam).
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[[Research Notes and Documents | Go to Research Notes and Documents]]
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[[Sajini Wijethunga| Return to Home Page]]
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Latest revision as of 10:52, 20 May 2019

Tech Notes

  • WF Calibration -- 5/4/18 Calibration of the UITF Wien Filter (WF) by adjusting the E-Field and B-Field to determine the velocity of the electron beam
  • Spring 2018 QE vs. Charge & Fall 2016 QE vs. Charge -- 5/24/18 Plots of QE vs. Charge data from the CEBAF injector. The Spring 2018 plot corresponds to when the vertical WF was at 50 degrees and the horizontal WF was off. The Fall 2016 plot is the opposite with the horizontal WF at 50 degrees and the vertical WF was off.
  • Magnetic field in front of photogun idea -- 5/25/18 An idea that I had that may solve the problem of ion back-bombardment due to ion creation downstream of the anode.
  • Derivation of QE Formula -- 6/1/18 Derivation of the formula for photocathode QE based on electron current, laser power, and wavelength
  • Magnetic Mirror Derivation - 9/19/18 Derived formulas for the criteria for ions to become trapped between two solenoids.
  • BPM analysis of electron beam - 9/20/18 Derivation and plots involving the analysis of an electron beam using a beam position monitor (BPM). One can detect and identify ions in the beam based on their characteristic oscillation frequency. Derivation follows from Alex Chao's Fast Ion Instability lecture notes.
  • Derivation of net force on ion - 10/3/18 Derivation of the net force on an ion between the biased anode and Magnetizing solenoid - should be helpful in determining the conditions for which an ion can be trapped between them.
  • How to run GPT on the JLab farm - 1/18/19 A tutorial on how to use the JLab farm to run many GPT simulations at once.
  • Derivation of Electron-Ion Momenta during Ionization - 5/20/19 Deriving the initial and final momenta of the primary electron, secondary electron, and ion during ionization, provided the target molecule is at rest. Given the initial momentum of the primary electron (based on the beam energy) and the final momentum of the secondary electron (based on the differential energy cross section), the remaining values for momenta before and after the collision can be derived.

GTS Field Map Layout

  • GTS Field Map Layout -- 10/11/18 Plot of the electric and magnetic fields through the first 1.2m of the GTS beamline using Gnuplot. The layout includes the field maps of the gun HV, biased anode, magnetizing (gun) solenoid, and the first two lenses (focusing solenoids), as well as vertical lines indicating positions of certain beamline elements (see GTS drawing)

July 2018 CEBAF Charge Lifetime Measurements

  • QE vs. Charge -- Plot of QE vs Charge between 10:13:00 and 15:12:00 on 7/11/18
  • Pickoff vs Inline -- Plot of pickoff power (to the photocathode) vs. inline power (before power meter) to determine power correction factor

Ion Bombardment of Solids Notes

Gun Voltage vs. Distance

RGA Spectra, Ionization Cross Sections, and Ion Production Rate

  • RGA Spectrum After 2 Days -- RGA Spectrum for gun chamber taken on 5/21/18 after prepping for 2 days, analyzed using gnuplot on 6/11/18. Each peak was fit using a gaussian function in order to determine the maximum and standard deviation of each peak.
  • Ionization Cross Sections V1 -- 6/14/18, Updated on 6/15/18, Analysis of the RGA Spectrum "After 2 Days" (see below), a sample calculation for the ionization cross section of hydrogen gas, and a plot of ionization cross section vs. beam energy (electron kinetic energy).
  • Ionization Cross Sections V2 -- 6/19/18 Updated document above to include section on numerical calculation of ionization rates.
  • Ionization Cross Sections V3 -- 6/22/18 Updated document above to include tables of calculated values for the ion production rates of the gas species using normalized partial pressures.
  • Ion Production Rate vs. Beam Energy -- 6/25/18 Formula derivation and plot of the ionization rate of gas species found in the "After 2 Days" RGA spectrum as a function of beam energy (gun voltage).
  • Ion Production Rate vs. Beam Energy V2 -- 8/27/18 Updated document above. Included a section on normalizing IPR to beam current. Also changed both IPR vs. beam energy plots to log-log so that the effect of ionization cross section on IPR is clearly seen.

Oral Qualifier Paper and Presentation

References

  • References -- List of references in bibliography format. Updated on 9/4/18

Go to Logbook

Go to Ghost Beam Studies

Return to Home Page