1. Presented by Shereen Aly Helwan University Group (experimental and data analysis) Dr. Ayman Mahrous Dr.Ahmed Ali Resistive Plate Chamber Activity At Helwan University Lab

2. Out lines: 1 What is RPC(Resistive plate chamber) Features of RPC Construction of RPC Helwan group activity for RPC

3. What is RPC(Resistive Pate Chambers): 2 Resistive plate chambers (RPC) are fast gaseous detectors with high time resolution),which is an important part of the Muon system in CMS experiment.

4. Features of RPC 3 Resistive plate chambers are gaseous detectors which aim to provide a muon trigger in both the barrel and end cap regions. High time resolution~1ns. the robustness and simplicity of construction. They are also well adapted to inexpensive industrial production.

5. Construction of RPC 4

6. Helwan group activity for RPC 5

7. 6 In frame work of completing our mission which is studying and testing new equipments were received recently from CERN which mainly consists of : Some electronic modules Channel gas mixture RPC

8. Gap tests: 7 1. The leak test: The Gap leak tests were performed by filling up the gaps Watching the pressure difference after 20 minutes, if the pressure change is less than 1% there’s no leak from the gap.

9. Gap tests 8 2- The spacer test: A transparent sheet having the layout of the spacer positions is kept aligned on the gap to be tested Pressure is applied at each spacer position and the change in the manometer reading is noted. Ideally there should be no change in the reading, for the gap to pass the test

10. Gap tests 9 3- The high voltage test: Gaps which passed the leakage and spacer tests were placed under high voltage with the gas mixture (Freon 95% and Iso-butane5%) working with HV (9.4KV) if the current is less than 2 µA, the gap is ok. High voltage cable

11. Chamber tests: 10 1. The Dark current(ramp current) test: The detector draws some amount of current even in the absence of any charged particle passing through it. This current is known as dark current. To determine dark current of a chamber, the chamber is connected to high voltage. Currents through each of the gas gaps were monitored.

12. Chamber tests: 2-Effeciency (TBD): in order to start the efficiency test we constructed and tested scintillator detectors(from Saitama university) where the efficiency is the ratio of the number of cosmicray muons detected by the chamber in coincidence with the- scintillator telescope to those detected by the telescope alone. 11

13. Chamber tests 12 3- strip occupancy(TBD): Strip response profiles are created to ensure all readout strips are active and working properly as they are supposed to. 4- Cluster size(TBD): The Cluster size is defined as the number of contiguous hit strips of the same chambers and it should be low(the- average  2 strips).

14. Conclusion: 13 The RPC is a gaseous detector with high efficiency. We’re working on RPC tests to study its performance successfully.

15. Acknowledgements: 14 Especial thanks to Dr.Ahmed Ali,Dr.Yasser Assran,Alaa Koutb and of course to the rest of my group: 1. Mohamed Soliman 2. Reham Aly 3. Asmaa Fawzi Ali 4. Ahmed Abdel Khaleq 5. Walaa Mohamed 6. Waleed Ahmed 7. Ahmed Hammad

16. Thank you

17. Backup 17

18. General principle of gas detectors 18 wall fill gas R Output A or Anode (+) e - Cathode (-) End window Or wall +

19. General principle of gas detectors 19 Voltage Number of Ion Pairs collected Ionization region Saturation Voltage 100 % of initial ions are collected Recom- bination region

20. What is RPC(Resistive Pate Chambers): 20 Streamer mode RPC:

21. What is RPC(Resistive Pate Chambers): 21 Avalanche Mode RPCs

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