Gas Analysis LHCb Analysis Results MWPC RICH2 RICH1 MWPC Low CO2 - - PowerPoint PPT Presentation

Gas Analysis

LHCb Analysis Results

MWPC RICH1 RICH2

MWPC Low CO2 Results

MWPC Calibration Factor

• MWPC BefPurif and ExhToDis showed low results

for CO2.

• The lower limit is 56%, however they are showing

55.32% and 55.29% respectively.

• The recent calibration conversion factor (31/10/17)

is 99.643% of the last one, whereas the areas calculated are 97.8%.

• Therefore the conversion factor does not account

for the significant change in result.

MWPC Pressure to Area Settings

• Last month the number of runs required for the analyses to stabilise

had increased to nearly 30

• A investigation into the relationship between the pressure setting of

the Bronkhorst and the concentration of gas present was conducted.

Comparing Area and Pressure

• Each gas, for each gas analysis and for each pressure

setting (5mbar, 10mbar, 12.5mbar) a plot was created comparing the area calculated and the 2 injection pressures (at the beginning and end of each injection).

• There is more of a correlation between the area and

pressure of analyses conducted at 5mbar. (example Argon MWPC Mixer

• This correlation is dependant on the Start Injection

pressure rather than the Ending injection pressure.

• This holds for 12.5mbar results which look very similar

to 10mbar.

• Full details of results in elog:

http://elogepdt-rdgas.cern.ch/Gas+Analysis/97

Plotting Area against Pressure

• The Area was plotted against Pressure for each gas in each

analysis to see the magnitude of the correlation.

• The data points cluster much closer to the trend line for

5mbar pressure setting, meaning there is a stronger

• correlation. (This holds for 12.5mbar results which look

very similar to 10mbar)

• Because of this and the smaller variation in Area values for

5mbar, it seems that 5mbar may be a better setting to perform MWPC in terms of conducting shorter analysis time.

• Full details of results are in elog:

http://elogepdt-rdgas.cern.ch/Gas+Analysis/102

Concentration Comparison

• However, after comparing the concentrations for each pressure setting, the areas calculated at 5mbar showed a

significant difference to those calculated at 10mbar.

• This would mean another calibration would need to be made if we were to use 5mbar

Problems

• Low MWPC CO2
• Bronkhorst Settings will not go
• ver 14mbar
• MWPC Run stability

Next Steps

• Perform MWPC Mixer analysis at

7.5mbar and compare Area-Pressure results and correlation with other pressure settings. Discuss which is best to use

• Determine the number of runs

required over time for each MWPC analysis and see if there is a trend.

• Discuss Bronkhorst Settings issue.

Remove any other limiting pressure setting that is causing problem

CMS Analysis Results

RPC DT CSC

ISE Station

Recent Data Trend

ISE Measurement Slope Breakdown

ALICE Procedures

• Procedures for checking and maintaining the ISE Station and GC-MS

Analysis has been made. It is saved in G:\Users\r\rpcgif\Public\ALICE MTR Summary and is also in hard copy at ALICE.

• It also has a checklist in Excel to be filled out whenever checking the

ISE.

Lab 256 Electrode Calibration Measurements

Problem

• Only one Electrode in use
• Only 2 Electrodes in calibration
• Neither of 2 in calibration are reaching

required slope value: 56

Next Steps

• Contact Adri to check any progress.
• Change sensor L to use in another body
• Introduce another electrode into Calibration

ALICE GC-MS Analysis

Problem:

• Trending higher Freon results in recent analyses

Next:

• Check chromatography of most recent analysis
• Complete GC-MS impurities