Radioactive Source Tests at OSU
12
1 OSU 9/7/03 Radioactive Source Tests at OSU urce tests are made using three Cs137 sources 0C sources (~15 years old, t1/2 Cs137=30.2yrs) s137 gives off: e’s (0.51MeV/94%, 1.2MeV/6%) ’s (0.662 MeV/85%) 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 > HV and monitor the current using CAEN system ests were performed on large cell tubes 10,12,13 l source tests were done using ZEUS gas mix
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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%) - PowerPoint PPT Presentation
Transcript of Radioactive Source Tests at OSU
1OSU 9/7/03
Radioactive Source Tests at OSU
Our source tests are made using three Cs137 sources10C sources (~15 years old, t1/2 Cs137=30.2yrs)Cs137 gives off:
e’s (0.51MeV/94%, 1.2MeV/6%)’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
Tests were performed on large cell tubes 10,12,13
All source tests were done using ZEUS gas mix
2OSU 9/7/03
Sources test setup
Cs source
Cs source
A Cs source
The bar holding the 3sources was moved by hand along the wire ~1 cm/s
3OSU 9/7/03
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, 62) I > 1A over the length of the wire
tube 10, wires 3, 4, tube 12 wire 4
3) I jumps up to > 1A over a region of the wire tube 12 wires 5, 7, tube 13 wire 2happens near the HV end of the tube
OK=low current, I<~1A uniform along wire
All 8 wires looked OK after a second scan ! Cycled HV, waited a few minutes and scanned
V=5700V
EXAMPLES on FOLLOWING PAGES
NOTE: on scan plots “400” is the voltage input end of tube
4OSU 9/7/03
Scan tests
Tube 10, Wire 6 (second pass)
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Position
Cu
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nt(
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Tube 10, Wire 6
Tube 10, Wire 6
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Tube 10, Wire 6
Tube 10 wire 6“Problem #1”
First scan Second scan
“400” is the voltage input end
“hot” regions
5OSU 9/7/03
Scan Tests
Tube 10, Wire 4
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Cu
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nA
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10-Current
Tube 10, Wire 4 (second pass)
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Cu
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Tube 10, Wire 4
Tube 10 wire 4“Problem #2”
First scan I>1A Second scan I<200nA
“400” is the voltage input end
1A
6OSU 9/7/03
Scan test
Tube 12, Wire 5
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Cu
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Tube 12, Wire 5
Tube 12, Wire 5 (second pass0
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0 50 100 150 200 250 300 350 400
Position
Cu
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nt(
nA
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Tube 12, Wire 5
First scan: I jumps >1A Second scan: I<1A
Tube 12 Wire 5“Problem # 3”
“400” is the voltage input end
7OSU 9/7/03
9/8 Scan Test
Tube 10 Wire 2 (9/8)
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1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298 309 320 331
Series1
Tube 10 Wire 3 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349 361
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Tube 10 Wire 4 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349
Position
Cu
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Series1
Tube 10 Wire 6 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349
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8OSU 9/7/03
9/8 Scan Test
Tube 12, Wire 1 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349
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Cu
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nt
(nA
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Series1
Tube 12 Wire 4 (9/8)
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1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298 309 320 331
Series1
Tube 12 Wire 5 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349 361
Series1
Tube 12 Wire 7 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349
Position
Cu
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nt(
nA
)Series1
9OSU 9/7/03
9/8 Scan Test
Tube 13 Wire 1 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349
Position
Cu
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nt
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Series1
Tube 13 Wire 2 (9/8)
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1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298 309 320 331
Series1
Tube 13 Wire 5 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349 361
Series1
Tube 13 Wire 6 (9/8)
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1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349
Position
Cu
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nt(
nA
)Series1
10OSU 9/7/03
Lateral Scan (3 tubes)Lateral Scan
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1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88
Tube 12 D
Tube 12 C
Tube 12 B
Tube 12 A
Tube 13 D
Tube 13 C
Tube 13 B
Tube 13 A
Tube 10 D
Tube 10 C
Tube 10 B
Tube 10 A
11OSU 9/7/03
“Long Term” Source Test
We let a source sit in one spot on tube for > 8hrs and monitored the currentLowered voltage to 5500V so current in a cell would typically be 200-300nAWe 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…..
12OSU 9/7/03
Source Induced Current !
If I put a source on the purple dot the current rises from<100nA to > 3A in 30-60 seconds !! The effect is reproducible with HV > 5700VCould this be a problem with the wire termination or resistor pc board??
