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name="MarkWard" |
-- Public.MarkWard - 05 Jul 2017 |
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> > | 2017-09-20
- Built script to extract anode and ground baselines based on the first few thousand samples (between the start -400ns, should probably be tightened up)
- Fits to baselines give parameters to perform data quality cuts, tell us which events in a run can be discarded.
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- Lab preparation, Zach and I mocked up an abomination of roughly the right maximum dimentions of the chamber and successfully passed it through the corridors to the lab.
- Turns out the roof of the clean tent is very heavy, thanks to everyone involved, minor emergency averted but the method of supporting the roof has to be much much stronger
- Probably use a shoring prop from a builders supplier if we cant come up with a better option
- Upstairs lab cleanup - We tidied up DARCO, The stand now has the following
- 1 power plug that feeds
- Camera power plug is independant
- High pressure gauge is independant
- It can be wheeled anywhere around the lab a requires 3 sources of power rather than how it was before, using 3 power bars with a squid work of cables. Much tidier and organised now.
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| 2017-09-13
- Lab Clean and preparation for recieving HPTPC
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- Stable for runs 2500-2600V
- Have observe the cathode feedthrough producing a glow,
- Spark rates appear higher with higher cathode voltage (no numbers, but just based observing behavour... seems like it makes sense given the charge collection should be better/more dense)
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- Taken a batch of 40 runs - about 3000 seconds of data
2017-08-30 |
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- Progress : Runners and rails - Done - Need review and sending to the workshop.
- Internal_Rail_Drawing_v1.pdf
- Field cage mounting system - Done - needs preparing into a drawing package, some screen shots
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- Each section bolts to the last in a string, via the 'bottom outer' 'top inner' bolting positions which allows the mount to have some rigidity
- A captured threaded rod busing arraingment means we don't require right handed and left handed threaded sections for adjustment
- We have 1 - 1.5 cm adjustment, we could try and design around more, requires the Field cage to be the correct diamater
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| 2017-08-16
- Moire pattern is visible in the pre-RHUL move and install
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- The patterning also appears similar in structure to that of the ion gauge picture, Top Left looks smooth, Top Right and Bottom left look distinct, and bottom right looks like there is a fine grid
- Looking back at our 40mbar CF4 data, I found that we had very few triggers, example, 700V data, with 40 1s exposures had a total of 10 triggers, that where actually spread over 3 events rather than a steady rate
- Turned out that looking at the config files, the channels where plugged into the digitizer as shown in photographs, and it appears to have been exactly reversed. Probable that the digitizer had already been disconnected and then quickly reconnected for a photo.
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- So, Good/interesting data is for 1600V Cathode - 710V Anode - 40.18mbar
- Some examples
- First Run of our sample - Event 1 has 16 triggers, all in the bottom left quadrant
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- Rise time vs Amplitude plot - All channels? (need to check what the code is doing)
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- Cathode sparking, is definitely detectorside and not a problem with the powersupply. I switched for a different supply and it was showing evidence of sparking. It being possible to hear the breakdown around the feedthrough. We should plan on either bakeout/modification/swapping for a bigger one when we next open up.
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- Current Vacuum achieved is 2.7x10^-6 - an improvement, maybe previous cathode cable was outgassing significantly.
- Installed LED light source for testing.
- Did focus testing with top right CCD in order to get a good focus. Setting that (by eye) gives good focus is just less than 0.6m on the focus ring (DOF indicator over the . of 0.6)
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- Matched all 4 cameras to same focus - Image below is a very lazy splicing together of the results, which are a vast improvement (originally so out of focus, you couldnt really see the anode frame)
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- Followed up with tests of the light source - Example with Red LED - operating at 1Hz, 20% duty, 0.7vPP, 0.35 offset
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- Light tightness tests
- Very preliminary though with our run config appears to be working, bias frames are taken shutter closed, proven during the focus testing
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| 2017-08-02
- Extensive voltage ramping of Anode/Cathode to gauge where we can get to reasonably
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TL |
TR |
BR |
BL |
Voltage |
714 |
735 |
760 |
748 |
Rate at stop |
0.04* |
0.04 |
0.025 |
0.025* |
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- Particle counts are returning to normal in the room, inside the clean tent levels are approximately normal
- Moved CF4 into the lab
- Pressurised DMTPC to 30.83torr (41.1mbar)
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- Final Voltage before ramp down 714.4 V, Spark rate ~ 1Hz
- Back down to 650V - spark rate reduced to ~0.4Hz
- Voltage Ramping of TR quadrent
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- Final voltage before ramping down 735.2
- Spark Rate.....?
2017-07-18 |
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- Cooling is back now (2-3 day downtime)
- TPC transfer frame completed to correct dimensions, Cathode and fieldcage installed onto the transfer frame
- Door resizing will be started on monday, - Target - TPC will be installed in the chamber before then! GO GO GO
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- Cage.jpg:
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- Cage.jpg:
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- Field Cage resistor chain is installed, link to cathode and link to ground to be done (but are single parts)
- Anode has been unpacked and has been hung on the frame with supports at the correct size
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- IMG_20170711_170058.jpg:
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- IMG_20170711_170058.jpg:
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- Need to make modification to bolting hardware, on the top mount (second part not with the equipment is adiquetly lengthed nylon or delrin bolts)
- Next steps will be cabling prep - on frame in air voltage tests
2017-07-05 |
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META FILEATTACHMENT |
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META FILEATTACHMENT |
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META FILEATTACHMENT |
attachment="Tracks_again.png" attr="" comment="" date="1504692011" name="Tracks_again.png" path="Tracks_again.png" size="538278" user="udap005" version="1" |
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META FILEATTACHMENT |
attachment="Baseline_Vs_Trigger.png" attr="" comment="" date="1505900626" name="Baseline_Vs_Trigger.png" path="Baseline_Vs_Trigger.png" size="180947" user="udap005" version="1" |
META FILEATTACHMENT |
attachment="Baseline_Sigma.png" attr="" comment="" date="1505900635" name="Baseline_Sigma.png" path="Baseline_Sigma.png" size="187756" user="udap005" version="1" |
META FILEATTACHMENT |
attachment="TriggerRates.png" attr="" comment="" date="1505900641" name="TriggerRates.png" path="TriggerRates.png" size="86639" user="udap005" version="1" |
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