Faraday Cup Measurment Notes » History » Version 2
Jim Pulokas, 10/04/2010 03:30 PM
| 1 | 1 | Jim Pulokas | h1. Faraday Cup Measurment Notes |
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| 3 | Picoammeter setup: |
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| 4 | * plug in |
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| 5 | * wait 1 hour |
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| 6 | * activate ZCHK (maybe already when turned on) (should say ZC on screen) |
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| 7 | * plug into faraday holder |
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| 8 | * set to lowest range (2nA) |
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| 9 | * activate ZCOR to set zero (should say ZZ on screen) |
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| 10 | * set auto range if desired |
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| 11 | * deactivate ZCHK to begin measuring |
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| 12 | 2 | Jim Pulokas | ** 1.00 nA |
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| 15 | h1. Exposure Time to Screen Current measurment |
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| 16 | |||
| 17 | * refer to Tecnai Help for "Exposure Time, Plate Camera CP" |
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| 18 | * formula: beam current (nA) = 2.15 * emulsion / measured_exposure_time |
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| 19 | ** exp time is between 3.1 and 3.5 depending on size of beam |
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| 20 | ** emulsion = 1 |
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| 21 | ** beam current is between 0.61 and 0.69 nA |