Eco-gas meeting RPC ATLAS+CMS et al

Wednesday 1 Jul 2020, 11:00 → 12:00 Europe/Rome

Vydio link: https://vidyoportal.cern.ch/flex.html?roomdirect.html&key=kDlqPrrizJ2m

Giorgia presented results of the Argon scan taken last week by Her, Gianluca and Amrutha

A new ELOG entry has been submitted:

Logbook: rpcecogaselog  Message ID: 71    Entry time: Wed Jun 24 10:41:41 2020

Author: Gianluca Rigoletti  Category: General  Subject: Argon scan performed

Argon scan was performed today (Giorgia, Gianluca, Luca, then Amrutha joined)

Scan performed manually via telnet

Spreadsheet with data and results attached and available on the link here:

https://docs.google.com/spreadsheets/d/1oAF6M1hnxFDbu2IGf-yUNpdxHzWawlzbkzdWlYiEQ5Y/edit?usp=sharing

 

Summary results:

In 10^10 Ohm*cm
Chamber	15/01/2020	23/06/2020
ALICE	16.50	82.01
CMS-K-TOP	16.80	38.19
CMS-K-BOT	14.50	26.08
CMS-GT-TOP	9.86	8.18
CMS-GT-BOT	8.96	12.05
EPDT	10.70

Alice chamber shows higher resistivity but it is not clear if due to bakelite or to a HV connector problem. Luca will try to check

GT chambers almost stable.

Kodel chamber show higher resistivity. The tests done in the past with low humidity seem to have affected the resistivity. Kodel bakelite is different from GT bakelite and seem to be more sensitive to humidity.

Next plans:

Luca check HV connector of Alice chamber. If it can be fixed than we will repeat the scan with not humidified Argon. If the connector was already good we will repeat the scan with humidified Argon to check how model and Alice behave.

Beatrice reported the need for a modification of the gas system putting a valve to switch from Argon to gas mixture in a easier way. It will be done this week. Gas will be stopped but the break should be few hours.

Cern chamber is at momenti not in the trolley because of a current leak and has to be checked in lab if leak of chamber can be fixed before going back in the trolley

 

Beatrice reported  the limits of the present mass flow controls MFC. 

At moment the limit is due to the MFC of the humidified mixture (max 6 lt/h) Beatrice will check if software intervention can change the limit. Or if a hardware fix can be found. Company will be contacted.

In case the fix is found the max flow could double.

Attachment 1: EcoGas_Mixture_CalculationMaxFlow.xlsx  299 kB  Uploaded Tue Jun 30 13:00:02 2020

ELOG V3.1.4-966e3dd

Davide will contact Nicolas to discuss the possibility to test the GT chambers with the LHCb setup in order to test the setup and to have a measurement of the efficiency with eco gas mixture.

 

11:00 → 11:20 Discussion on argon test results

Speaker: Gianluca Rigoletti (CERN)

11:20 → 11:40 Discussion on gas Flow limits

Speaker: Beatrice Mandelli (CERN)

EcoGas_Mixture_CalculationMaxFlow.xlsx