Univerity of rome “Tor Vergata” Analysis of MDT chamber performance in terms of efficiency and noise rate Motivation Basic idea Description of the analysis Application to the measurament of the RPC induced noise 5. Conclusions Univerity of rome “Tor Vergata” Infn - Frascati Silvia Ventura

Motivation The main motivation is to study and implement a fast monitoring procedure for off-line and possibly on-line data analysis, in order to check the efficiency and the noise rate of the MDT channels

Basic idea The basic idea is to use the hit counting rate (beam profile) together with the information avalaible from the MDT channels, that are the TDC and ADC values.

BML1 & BML2 Multilayer 1 Layer 3 Beam Profile From the beam profile one can obtain information about the noise and the efficiency. In particular we study the beam profile of all the layers. Hit counts BML1 BML2 Plot di beam profile Tubes number BML1 & BML2 Multilayer 1 Layer 3

TDC & ADC spectra Hit counts Hit counts Events Events in time Events out of time Events out of time Hit counts Events with ADC<40 Events with ADC > 40 Hit counts

TDC spectrum ADC spectrum ADC > 40 ADC < 40 BIL multilayer1 layer3 ADC spectrum 580<TDC <1550 TDC<580 , TDC>1550

TDC spectrum ADC spectrum ADC > 40 ADC < 40 BML multilayer1 layer1 ADC spectrum 580<TDC <1550 TDC<580 , TDC>1550

So we choose to define 4 different categories of events: 1. ADC > 40 out of time 2. ADC < 40 out of time 3. ADC > 40 in time 4. ADC < 40 in time …and look at the corresponding beam profile for the BML multilayer 1 layer 1.....

Beam profile for the 4 categories: ADC>40 Out of time ADC<40 Out of time ADC>40 In time ADC<40 In time BML1 & BML2 multilayer 1 Layer 1

For all the categories we integrate on all the tubes for each layer  Nlayer ADC>40 Out of time ADC<40 Out of time BIL BML BOL ADC>40 In time ADC>40 In time

We can get information about: Noise rate using 2 and 4 The 4 categories are: 1. ADC > 40 out of time 2. ADC < 40 out of time 3. ADC > 40 in time ADC < 40 in time We can get information about: Noise rate using 2 and 4 Efficiency using the clean beam profile of event 3

Evaluation of noise rate Noise(Hz) = counts(ADC<40)/(Dt x triggers) Hz BML1 BML2 BML1 & BML2 multilayer 1 Layer 1 Additional studies: Do RPC induce noise?

Data sample: Data from test beam 2003 H8: Run number Active detectors 700090 MDT 700108 700334 1091 MDT + RPC 1165 MDT (only BIL2,BML2,BOL2) + RPC 1559 1764

Noise from RPC (?) Run 700334 Run 700090 Runs without RPC… Hz For all the layers the noise averaged on all the tubes BIL BML BOL Run 700090 Hz BIL1,BML1,BOL1 BIL2,BML2,BOL2 BIL BML BOL

Noise from RPC (?) Run 1764 Run 1559 Runs with RPC... Hz Hz BIL BML BOL Run 1559 Hz BIL1,BML1,BOL1 BIL2,BML2,BOL2 BIL BML BOL

Noise from RPC: Conclusion Averaging the noise on all the chamber we see that there is not a significant difference of noise rate Hz Run 700090 Run 700108 Run 700334 Run 1559 Run 1764 BIL1, BML1, BOL1 Run 1091 Run 1165 BIL2, BML2, BOL2 Hz

Beam profile for all the layer Efficiency Using the beam profile of events in time with ADC > 40 we can evaluate the efficiency for all the tubes of a layer BML mutilayer1 layer1 layer2 layer3 Tubes number Beam profile for all the layer Tubes number Shifted tubes number

Conclusions:  An analysis has been made of the hit counting rate and of the TDC and ADC information to determine the efficiency and noise rate of the MDT channels.  The ADC cut is powerful in selecting signal and noise hits. The application of this analysis to study the RPC induced noise has shown that it was negligible at H8 The comparison of the beam profiles observed in the various active detector layers makes the analysis indipendent of the actual beam profile. A code to perform sistematically the analysis and determine efficiency and noise rate for all individual channels is under development