1 / 12

Radioactive Source Tests at OSU

Radioactive Source Tests at OSU. Tests were performed on large cell tubes 10,12,13. Our source tests are made using three Cs137 sources 10 m C sources (~15 years old, t1/2 Cs137=30.2yrs) Cs137 gives off: e’s (0.51MeV/94%, 1.2MeV/6%) g ’s (0.662 MeV/85%)

owen-small
Télécharger la présentation

Radioactive Source Tests at OSU

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. Radioactive Source Tests at OSU Tests were performed on large cell tubes 10,12,13 Our source tests are made using three Cs137 sources 10mC sources (~15 years old, t1/2 Cs137=30.2yrs) Cs137 gives off: e’s (0.51MeV/94%, 1.2MeV/6%) g’s (0.662 MeV/85%) We did two types of sources tests “scan” test (V=5700V) moved the 3 sources sources (by hand) ~1 cm/sec “long term” test (V=5500V) let a source sit in same location on tube for > 8hrs Set HV and monitor the current using CAEN system All source tests were done using ZEUS gas mix

  2. Sources test setup A Cs source The bar holding the 3 sources was moved by hand along the wire ~1 cm/s Cs source Cs source

  3. Cs137 Scan Tests Each wire was scanned with a source. Initial Study found: 16 wires “ok” 8 wires suspect types of Problems: 1) I increases in a few regions of wire tube 10, wires 2, 6 2) I > 1mA over the length of the wire tube 10, wires 3, 4, tube 12 wire 4 3) I jumps up to > 1mA over a region of the wire tube 12 wires 5, 7, tube 13 wire 2 happens near the HV end of the tube V=5700V OK=low current, I<~1mA uniform along wire EXAMPLES on FOLLOWING PAGES All 8 wires looked OK after a second scan ! Cycled HV, waited a few minutes and scanned NOTE: on scan plots “400” is the voltage input end of tube

  4. Scan tests Tube 10 wire 6 “Problem #1” “hot” regions First scan Second scan “400” is the voltage input end

  5. Scan Tests Tube 10 wire 4 “Problem #2” 1mA Second scan I<200nA First scan I>1mA “400” is the voltage input end

  6. Scan test Tube 12 Wire 5 “Problem # 3” Second scan: I<1mA First scan: I jumps >1mA “400” is the voltage input end

  7. 9/8 Scan Test

  8. 9/8 Scan Test

  9. 9/8 Scan Test

  10. Lateral Scan (3 tubes)

  11. “Long Term” Source Test We let a source sit in one spot on tube for > 8hrs and monitored the current Lowered voltage to 5500V so current in a cell would typically be 200-300nA We have sampled 12 spots so far 4 spots on each tube, ~L/5, 2L/5, 3L/5, 4L/5 Current is very stable in each region HOWEVER…..

  12. Source Induced Current ! If I put a source on the purple dot the current rises from <100nA to > 3mA in 30-60 seconds !! The effect is reproducible with HV > 5700V Could this be a problem with the wire termination or resistor pc board??

More Related