Difference between revisions of "Bubble Chamber Meeting Wednesday October 7, 2015"
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* Beam Test Summary (Ernst): | * Beam Test Summary (Ernst): | ||
# ''Plus'' | # ''Plus'' | ||
− | ## | + | ## Chamber operated as expected in Bremsstrahlung beam |
− | ## | + | ## Will be able to measure the chamber ''insensitivity'' to gammas – we had a high intensity gamma flux on chamber |
+ | ## Measured <sup>18</sup>O(γ,α)<sup>14</sup>C cross section at five energies | ||
+ | ## Found sensitivity as expected to <sup>14</sup>N(γ,p)<sup>13</sup>C when lowering the operational pressure | ||
+ | ## Cosmic background of about 1 bubble every 4 minutes in JLab tunnel vs 1 – 2 bubbles every minute at Duke or Argonne | ||
# ''Minus'' | # ''Minus'' | ||
− | ## Events distribution shows a cone instead of a cylinder | + | ## Chemistry of mercury – why background rate changed at the end of test |
− | ## | + | ## Events distribution shows a cone instead of a cylinder – why? |
+ | ## Ceramic break failed | ||
+ | ## Beam position on radiator | ||
+ | ## Better alignment | ||
# ''Improvements'' | # ''Improvements'' | ||
## ''Easy'' | ## ''Easy'' | ||
### Better light coverage | ### Better light coverage | ||
### Improve cooling capacity | ### Improve cooling capacity | ||
− | ### Introduce a lens to locate camera farther and better shielding of gammas (camera was sensitive to gammas) | + | ### Introduce a lens to locate camera farther and for better shielding of gammas (camera was sensitive to gammas) |
### Improve operational pressure control and regulation | ### Improve operational pressure control and regulation | ||
### Be able to take data from MCC instead of Injector Service Building | ### Be able to take data from MCC instead of Injector Service Building | ||
## ''Tough'' | ## ''Tough'' | ||
− | ### One fluid system | + | ### One fluid system – no more mercury |
### New collimator in chamber | ### New collimator in chamber | ||
* Beam Energy: | * Beam Energy: | ||
− | # | + | # Added steel to cover about 80% of 2D spectrometer line |
+ | # Calibrated ¼ cryounit gradients using 2D line | ||
+ | # Will check beam energy in 5D line – as of now, beam energies used during September test could be off by few percents | ||
+ | # Will add steel shielding to 5D line next SAD |
Latest revision as of 16:10, 18 November 2015
We will meet in TL 2221 on Wednesday October 7 at 3:30 pm EST.
For those calling in we'll use the Blue Jeans [1] audio conference system.
Phone number: 1-888-240-2560 Meeting ID: 3528502673# Meeting URL: http://bluejeans.com/3528502673
Agenda:
1- Bubble Chamber removal and shipping back to ANL
2- September beam test summary
Notes from this meeting:
- Bubble Chamber Removal:
- Planned on October 20 and 21
- Crates will be staged by October 19
- Plan to ship every thing back to Argonne
- Shipping arrangement will be made once chamber is crated and ready in north tunnel access building
- Beam Test Summary (Ernst):
- Plus
- Chamber operated as expected in Bremsstrahlung beam
- Will be able to measure the chamber insensitivity to gammas – we had a high intensity gamma flux on chamber
- Measured 18O(γ,α)14C cross section at five energies
- Found sensitivity as expected to 14N(γ,p)13C when lowering the operational pressure
- Cosmic background of about 1 bubble every 4 minutes in JLab tunnel vs 1 – 2 bubbles every minute at Duke or Argonne
- Minus
- Chemistry of mercury – why background rate changed at the end of test
- Events distribution shows a cone instead of a cylinder – why?
- Ceramic break failed
- Beam position on radiator
- Better alignment
- Improvements
- Easy
- Better light coverage
- Improve cooling capacity
- Introduce a lens to locate camera farther and for better shielding of gammas (camera was sensitive to gammas)
- Improve operational pressure control and regulation
- Be able to take data from MCC instead of Injector Service Building
- Tough
- One fluid system – no more mercury
- New collimator in chamber
- Easy
- Beam Energy:
- Added steel to cover about 80% of 2D spectrometer line
- Calibrated ¼ cryounit gradients using 2D line
- Will check beam energy in 5D line – as of now, beam energies used during September test could be off by few percents
- Will add steel shielding to 5D line next SAD