1. SHLC INFN Road Map Working Group 11/01/2006
Background
The entire stand-alone muon system has been designed to handle background rates up to 5 times the LHC expectation with minor degradation of performances
At the SLHC at L= 1035 cm-2s-1 there will be an obvious increase of the background counting rate (naively a factor 10) with present shielding
An improved shielding is under study by the ATLAS shielding group
a factor about 2 in the background reduction is achieved with a new Berillium pipe up to z=16m
A. Di Ciaccio
SHLC INFN Road Map Working Group 11/01/2006

2. SHLC INFN Road Map Working Group 11/01/2006
(1)
With the assumption that :
the background rates at LHC are correct (and so also at SHLC)
The shielding factor of at least 2 is reached
>>>>we conclude that the present RPC detector can operate as it is at the SLHC
however without safety factors
on the base of the studies and the today understanding of the RPC ageing (see my presentations of November 14th and November 25th
A. Di Ciaccio
SHLC INFN Road Map Working Group 11/01/2006

3. RPC High pt trigger rate@SLHC
Nisati
A. Di Ciaccio
SHLC INFN Road Map Working Group 11/01/2006
L=1035cm-1s-1

4. SHLC INFN Road Map Working Group 11/01/2006
(2)
In about 2 years from now, when the LHC will start, the background rates will be definitely clear and we can check the above hypotesis.
Suppose the measured background rate (and its extrapolation at L=1035 cm-1s-1) is higher than expected.Question:
it would be possible in a simple way to make more robust the high pt muon trigger ?
New possibility: add an extra RPC doublet in the outer muon station to strength the high pt muon trigger
A. Di Ciaccio
SHLC INFN Road Map Working Group 11/01/2006

5. SHLC INFN Road Map Working Group 11/01/2006
Level 1 Muon Trigger .
Two trigger thresholds : Low pt (6 Gev/c threshold) and High pt (20-40 Gev/c threshold)
New RPC Layer
A. Di Ciaccio
SHLC INFN Road Map Working Group 11/01/2006

6. Gas volumes and spacers
ATLAS RPC
Support panel
Gas volumes and spacers
Strips panels (x,y)
Separating panel
Strip panels (x,y)
Front end electronics
A. Di Ciaccio
SHLC INFN Road Map Working Group 11/01/2006

7. SHLC INFN Road Map Working Group 11/01/2006
What needed
The proposed scheme requires first detailed MonteCarlo simulation studies :
define the best scheme
quantify the advantages
Muon layout modification:
A fourth RPC doublet to be constructed for BOL/BOS outer stations with a new common support structure
To be still discussed in ATLAS within the muon and trigger community
A total of ~200 new BOS/BOL RPC units (1x6m2) have to be made with new FE electronics for the extra fourth layer
A. Di Ciaccio
SHLC INFN Road Map Working Group 11/01/2006

8. Preliminary cost estimation
>2007
R&D on gas mixture (freonless mixture)
MC calculations for the new trigger scheme
Prototype studies
>2010 RPC Construction
Years 2007,2008,2009
years 2009,2010
year > 2010
R&D program
Prototypes, modules 0
Constrution
Detector
Needs
cost for INFN
total Cost
RPC
Ageing studies
0.5ME
A. Di Ciaccio
SHLC INFN Road Map Working Group 11/01/2006