1 / 19

Different source designs for particle ionization in a pulsed glow discharge

Different source designs for particle ionization in a pulsed glow discharge. Farzad Fani Pakdel November 16, 2006. Objective: Ionization of particles by pulsed glow discharge and study the ions with TOF-MS. Anode. Ar plasma. TOF detector. CsI particles. ions. Cathode. I +. Cs +.

danae
Download Presentation

Different source designs for particle ionization in a pulsed glow discharge

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Different source designs for particle ionization in a pulsed glow discharge Farzad Fani Pakdel November 16, 2006

  2. Objective: Ionization of particles by pulsed glow discharge and study the ions with TOF-MS Anode Ar plasma TOF detector CsI particles ions Cathode I+ Cs+ High energy electrons Pre-peak Fragmentation Penning ionization Soft, ( CI ) After peak

  3. Pulsed Glow Discharge Synchronized with TOF repeller f = 100 -1000 Hz Discharge pulse, Ionization Repeller of time of flight Will send a packet of ions to detector time 0 20 ms 0 - 300 ms

  4. Experimental Setup GD TOF Solution of A salt (NaCl)

  5. Discharge source: sleeve Argon flow cathode Insulator Anode ions TOF detector Argon flow carryingparticles skimmer Pressure gauge pump

  6. Cesium Iodide (2.5mM) and Rubidium Iodide (7.5mM) Intensity (mv) I+ 85Rb+, 87Rb+ Cs+ Brass Ar2+ Mass / charge (amu)

  7. Sodium Chloride (17mM) and Magnesium Nitrate (16mM) Repeller delay time = 56 msec Na+ Intensity (mv) Mg+ Cl+ H2O N2 O2 Ar + , ArH+ Mass / charge (amu)

  8. Problems: -Can not increase the flow -Clogging at needle valve as a result -Particles pass very fast -Signal was not reproducible sleeve cathode Insulator Anode ions skimmer Corrosion (sputtering) Pressure gauge pump

  9. Changing the anode design (anode C) + Increases the residence time for particles + Higher flows allowed (500, instead of 150 ml/min) -Reduces the ion transfer yield cathode Insulator Anode Cathode Anode

  10. Comparing Anodes No particle Only argon A2 C2 B2 Signal intensity (mv) Ar = 40 ArH = 41 Cu = 63 20 40 60 80 100 Repeller delay time (ms)

  11. Ionization of CsI particles Nebulized from 10mM CsI solution (Anode C) Max Cs+ signal at 58-60 ms Signal intensity (mv) Repeller delay time (ms)

  12. Signal stability study (Cs) Repeller delay is fixed at 58 ms Integ time = 3s 2mM 0.5mM 0.1mM 1 mM Collection time (0-14min)

  13. Cathode after ionization with anode C

  14. Argon only, through the back sleeve Max sputtered? Ar = 40 ArH = 41 Cu = 63 Signal intensity (mv) Penning ionization Repeller delay time (ms)

  15. Ideal design! + Allows more residence time for particles + Higher flows allowed (500, instead of 150 ml/min) + Argon back flow interacts with particles and increases their residence time, enhances ionization (Penning) *no more reduced ion transfer yield Argon flow cathode Insulator Anode Cathode Anode

  16. Ionization study by emission spectroscopy vacuum Anode Cathode (-) emission Particles detector Insulator Argon in

  17. Laser ablation with anode C cathode Insulator Anode laser Cathode Anode

  18. Laser Ablation Laser mirror Lenz

  19. 63Cu signal by time in successive spectrums (Transient mode) = 240 mass specs Laser on Intensity (mv) 240 sec 0 sec Time Power supply on

More Related