1. Status of muon monitor R&D and construction
Specification
Detector support structure
Ionisation chambers
Acquisition system

2. Functional specification
Goal, monitoring of:
muon intensity
muon beam profile shape
muon beam profile centorioid
Dynamic range: 105
Muon intensity: 7.7x107 per cm2 and 10.5 ms
Pulse duration: two pulses of:
length 10.5 ms
separated by 50 ms
Accuracies:
absolute 10 %
relative 3 %
reproducibility: - cycle to cycle 1 %
- one year 5 %
x 10 5 -2 -1 1 2
1.0
2.0
3.0
4.0
r (m)
2nd muon pit

3. Ionisation Chamber Calibration and Support Structure
Fixed chamber mounted on cross shaped structure (AL)
Movable chamber behind fixed monitors for relative calibration
Design finished
Start of Production 06/2004
Movement by stepping motors (no resolvers)
Motor driver standard SPS (MIDI) installed in UA 87 (distance 500 m) (available)
Interface to network via ionisation chamber acquisition system (RS232)
Cables ordered
Front end software driver available
Stainless and AL
Beam
Steel

4. Visual Inspection of Structure
Camera 5 m upstream
Radiation hard camera (tubes) (available)
Standard SPS TV system installation located in UA 87 (distance 500 m ) (available)
TV frame transmission via Ethernet
Cables ordered
Front end software driver available
Observation Camera

5. Ionisation chamber LHC design Parallel electrodes separated by 0.5 cm
Stainless steel cylinder
Al electrodes
Low path filter at the HV input
N2 gas filling at 100 mbar over pressure
Start of production in 2004
diameter = 8.9 cm, length 60 cm, 1.5 litre

6. Ionisation Chamber Test in Proton Beam BOOSTER
Chamber beam response
Chamber current vs beam current
slength proton= 50 ns
Intensity discrepancy
by a factor two
FWHMe-= 150 ns
Measurements with SPS
extracted beam foreseen
for 2004 (absolute calibration)
Intensity density: - Booster prot./cm first pit muon/cm2

7. Principle Schematic of Current Integrator
SPS design (about 10 years in operation)
Low bias current input amplifier (< 100 fA)
Reset with switch across feedback capacitor
Gain switched:
C1 and C2 (1, 200)
Amplifier (1, 4, … 128)
Digitalisation by 12 bit ADC

8. Acquisition Electronics
1 VME crate for acquisition
Crate CPU: PowerPC
Timing by TG8 module
Integrators on 8 channel card
5 cards for whole set up
Hardware set up and software driver are available

9. Ionisation Chamber and Electronics Tests SPS (I)
SPS system:
Ionisation chambers with parallel electronic geometry (0.5 cm separation)
Electronics in surface buildings with a analog signal transmission of about 1.5 km
Operation time:
chambers over 20 years
electronics 10 years
Total received dose:
ring 0.1 to 1 kGy/year
extr 0.1 to 10 MGy/year muon
Test method:
Chamber gas ionised with Cs source
Observation of created charges with installed electronics (about 180 chambers)

10. Ionisation Chamber and Electronics Tests SPS (II)
SPS Results:
Relative variation between:
successive acquisitions (cycle to cycle reproducibility 0.01) Ds/s < 0.005
between different monitors (relative accuracy 0.03, year to year reproducibility 0.05) Ds/s < 0.01 (for ring BLMs) Ds/s < 0.05 (for Extr., inj. BLMs)
Total dose in muon pit 1:
peak 45 kGy/year

11. Summary Support structure could be ready for installation in 2004
Motorisation available and ready for installation
Observation camera setups available and ready for installation
Ionisation chambers start of production in 2004 installation in 2005
Ionisation chamber time response match specification
Ionisation chamber linearity to be tested at muon intensity density in 2004
Data acquisition system available and ready for installation
SPS ionisation chamber tests show high relative accuracy and long term stability of system