2009 Summer Updates- Summer Student Report
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Transcript of 2009 Summer Updates- Summer Student Report
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2009 Summer Updates- Summer Student ReportEmine AltuntasStephen Fee
Supervisors: Mar Capeans, Ivan Glushkov, Roberto Guida
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Gamma Irradiation
Facility (GIF) RPC
Gas System
+GIF Humidity and Temperature Control System – The Tent
Construction and operation of the tent
Purpose of tent:
- Controlled environment for temperature and humidity for the chambers
- Achieved by temperature and humidity control devices
- Conditions monitored by measurement devices in the tent
- Tent is now sealed and operational at the GIF!
Current Status Inside The GIF
2 m 2 m
2.5
m
+GIF Humidity and Temperature Control System – The Tent
Current Status Inside The Tent
+GIF Irradiation positioning
RPC Tent
ATLAS TentOld
position
Safety zone
Safe
ty zo
ne
ATLAS Tent
Desired position
+ GIF Humidity and Temperature Control System – The Tent
- Current conditions in tent are approximately 40 %RH to 50 %RH, temperature of 20 °C
- Maintained at this state by the dehumidifier and air conditioning
Air conditioner - Control of Temperature and Dehumidification (but not to setpoint)-Dehumidifier - Dehumidification (not to setpoint)-Both are protected by lead shielding
- Limitations: the devices cannot be controlled remotely, no set point for humidity
+GIF Humidity and Temperature Control System – The Tent
Measurement Devices in Tent
Hygrometer
Weather Station
- Hygrometer gives measurement of temperature and humidity in the tent
- No need to protect from radiation – mechanical device
- Needs regular checks for ink and paper changing-Weather station records live data to a PC in the GIF
- This data can be accessed remotely at any timeConclusion: We now have a system to control and measure the temperature and humidity for the chambers
+Checklist for the GIF - RPC Gas System
The RPC gas system checklist is completed every day.
A hard copy of each day’s checklist as well as an excel file record is kept for future data analysis.
In addition to the points shown here the supply mixture peak areas and the MS vacuum quality concentration units are recorded.
The supply mixture peak area and concentration values can be found at https://twiki.cern.ch/twiki/bin/view/LHCgas/GCMS.
With the transition to the closed loop configuration new check points need to be added.
A log file is added to each day’s GC-MS analysis folder at the GIF.
Thus data collection process can be followed more accurately in the future.
Closed loop
Open mode
+Checklist for the GIF - RPC Gas System Right now the gas mixture is
analyzed with the MS-GC every day at 6 different points:
Supply gas mixture to the open loop Return gas mixture from the open
loop After MS5A purifier in the closed
loop After NiAl purifier in the closed loop After R11 in the closed loop The return mixture after all the
purifiers in the closed loop
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- Originally in the gas system, flow in ≠ flow out. More than 50% of gas was missing
- Does not represent closed loop conditions, and costs money
- Leaks suspected in the system
GIF Gas System - Leak Hunt
+Leak detection
- Firstly general gas detector and a Freon gas detector were used on the whole system
- These devices identified many leaks in the system
- Connection points, Teflon tape
- Solution: Tightening of connections, replace tape, assistance from technicians
- Still many leaks remained…
GIF Gas System - Leak Hunt
+Helium Leak Detector
Procedure:
-Run the system with 5% Hydrogen in nitrogen
- Hydrogen will be released at high rate through the smallest leaks (small molecular size)
- The detector was found to be very specific and accurate in the leak detection
- Leaks were then fixed, the system is now running with no major leaks
Conclusion: The helium leak detector is much more specific and faster than other methods and should be used for future leak detection
GIF Gas System - Leak Hunt
+Purifiers and Regeneration The Purifiers Tested At the GIF
The open loop purifiers
Molecular Sieve 3A, 4A, 5A
NiAl, NiSi, R11, R12, SiGel
2 l cartridges
The closed loop purifiers
Cartridge 1 (big one): 90 % MS4A + 10% MS5A
Cartridge 2 (small one): R11
Cartridge 3 (small one): NiAl
The concentration levels of H2O and O2 are analyzed in every data collection.
Over time the sieves of each purifier become clogged. And purifiers do not perform at the desired level.
The increase in the tendencies of H2O and O2 levels indicate the need for regeneration.
+Purifiers and Regeneration Regeneration Process
The heat controller
Gas System Rack
Regenerator
Gas flow control rack
+Purifiers and Regeneration Regeneration Process
Inside the toaster the purifiers have been heated to 230 C
Each purifier is flushed with a standardized mixture of argon and 5% hydrogen.
In the case of MS4A and MS5A, as the purifier is heated the opening of the sieves increase.
As the purifier is flushed with gas, the molecules stuck between the sieves are removed.
Each purifier is regenerated for fourteen hours.
After the heat is turned down each purifier is flushed with the standardized gas mixture for another four hours.
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+Purifiers Table
4A 5A R11 Nickel Aluminium
Nominal Absoprtion capacity21% w/w
water22 % w/w
water 45-97 g/kg water No data
0% oxygen 0% oxygen4l O2 per 1 kg
catalyst17l O2 per 1l
catalyst
Amount in GIF set-up (g) 240.3 224.58 251.9 274.6
Expected lifetime for nomimal gas flow in GIF set-up (h)
Conditioning time (measured for each cartridge individually) [min]
Component of the RPC nominal gas mixture abosorbed by the purifier
Conditioning time of the whole set of absorbers together [min]
+GIF - RPC Gas System Checklist Data Analysis Purpose – To acquire
comprehensive and comparative graphs of the recorded values over time for further analysis
Method: The ISR RPC gas system checklist code is taken as the start point.
With the updates the current code;
Reads data records from the checklist excel file
The output graph files are recorded in the analysis folder
Each data entry is assigned to representative holder
Min and max finding for constructing the graphs
+GIF - RPC Gas System Checklist Data Analysis With the updates the current
code; A comparative graph of
active zone & open loop mixture temperature and RH values
A graph displaying the change in the current over time in each channel
The percentage deviation from the average current in each channel
Fresh gas mixture composition
+Air Calibration Report
Air calibration required to assist on ongoing gas measurements at the GIF
Aim: To achieve calibration for main components of air, plus additional components detected
Procedure: Analyse a known concentration of component using the GC-MS device
Result: The peak area can then be equated to the known concentration
+Air Calibration ReportOxygen Calibration
Achieved by analysing atmospheric air (21 %v/v oxygen) and bottle of 50 ppm oxygen in argon
Oxygen presents in module C (molecular sieve) of the GC (cannot separate air in modules A or B)
Oxygen could not be isolated from the 50 ppm analysis: Argon and oxygen peaks present at the same time
The calibration is thus based on analysis of air only
+Air Calibration Report
Achieved by analysing atmospheric air, 78 %v/v Nitrogen
Nitrogen presents in module C (molecular sieve) of the GC (cannot separate air in modules A or B)
Achieved by analysing atmospheric air
CO2 presents in module B (PPU) of the GC
The concentration of CO2 in atmospheric air is taken to be 0.0383 % v/v for the calibration calculations.
Nitrogen Calibration
Carbon Dioxide Calibration
+Air Calibration ReportWater Calibration
Achieved by analysing atmospheric air and bottle of 110 ppm water in argon
Water presents in module B (PPU) of the GC
Water peak from air Water peak from 110 ppm analysis
Ratio of peak area to concentration for 110 ppm analysis = 10.07
The two results are not in agreement. Reason : The air analysis is not guaranteed to be accurate due to the possibility of change in the absolute humidity of the sample. This is because of the discrepancy between atmospheric pressure and GC carrier gas pressure. Thus the calibration is based on 110ppm water in argon analysis
Ratio of peak area to concentration for air analysis = 1.35
+Air Calibration ReportArgon Calibration
Achieved by analysing bottle of (almost 100%) argon
Argon presents in modules A & B of the GC
+Air Calibration ReportConclusions
Calibration now available for the components of air:
Component Module Appearing in Time of peak value (s) Peak area corresponding to 1% v/v (µVs)
O2 MS5A 40 30987
N2 MS5A 43.6 30712
CO2 PPlotU 23.3 46823
H2O PPlotU 80.9 13541/100673
Ar OV1/PPlotU 17.3 14187/30644
+Looking Ahead The existing checklist needs to
updated with the addition of closed loop parameter readings
Such as, the closed loop temperature and humidity values
It is necessary to complete and test the ROOT checklist analysis code
For purifiers, regeneration is essential to be conducted without stopping the system and interrupting the data collection
Thus a similar setup to the one existing at LHC may be considered – of course taking into account time scale of this update and costs
The F- production rate to be studied
Hanna double channel analysis station
MS-GC software problems
The temperature and humidity control to be established for a long time in the tent –
no short term fluctuations
recording of values
+Acknowledgements
Experience with C++ and ROOT Introduction to the gas systems The physics behind the RPC’s
and RPC performance issues Other elements on RPC selection MS – GC analysis procedure Experience with MS – GC
software integration techniques Lectures by leading physicists in
the field Trips to the LHC experiments
Thanks for all the support And assistance And discussions -
explanations And fun conversations
+Personal Thoughts… The aims are challenging since:- Many impurities- Varying concentrations- Some concentrations very low = difficult to remove- Unknown effects on the chambers
Good Luck!
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+Acknowledgements and Thanks New experiences:- CERN- RPC- Working with radiation- Analysis methods and data analysis Outcomes:- Experience in international working environment- Further knowledge and experience in important areas- Looks great on my C.V.!
Thanks and please continue!
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