LHCb Muon Group – Status and Outlook

(May 1999)



This is an internal document for the institutes belonging to the LHCb muon group. It should serve as a guideline for requests to be made by the institutes to their funding agencies. Moreover, it clarifies some points related to the current phase of the muon project.



1. Present Activities in the Participating Institutes

CERN: - Coordination

- Optimization studies, software development

- MRPC R&D, FE-Electronics

- Testbeam support, gas system

CPPM: - Trigger implementation

- Background studies

INFN: - TGC R&D (Rome I)

- RPC R&D (Rome II)

- FE-Electronics (Cagliari)

- Participation in optimization studies and software development (beginning)


- Background studies

- Optimization studies

- Ideas on Trigger implementation


- Contribution to FE-electronics and trigger implementation

- Software development (beginning)


Nanjing No involvement at present in the muon group activities






2. Manpower Situation (in Full Time Equivalent FTE)


10/1998 – 03/1999

04/1999 – 03/2000



5-6 FTE

Rome I


5-6 FTE





0.5 FTE

1-2 FTE


4-5 FTE




4-5 FTE


3. New Groups, their Interest and Manpower Situation

INR Warsaw: - Electronics

- 1-2 FTE from second half 1999 onwards



4. Cost Estimate

The numbers given below are based on a rough estimate made for version 1.2 of the LHCb CORE document (06/1998). A more solid estimate should be available by September 1999. The iron absorber will be provided by CERN and has been valued at 4 MCHF. This leaves 6 MCHF for the detector, including some expenses for work on the iron. The cost of the L0-Muon-Trigger and the DAQ relevant for the muon system is not included. An effort should be made to stay within the ceiling of 6 MCHF.

Chambers: 1.6 MCHF

Electronics: 3.3 MCHF

Service Systems: 0.6 MCHF

Iron: 4.5 MCHF

Sum: 10 MCHF


5. Expected Financial Contributions


Russia: 1-1.5 MCHF

CNPq Brazil: around 1.2 MCHF

Poland: around 0.1 MCHF

CERN: as necessary


6. Major Milestones up to the Technical Design Report (TDR)

Choice of Technologies (Detector and Electronics): 01/2000

Finalize Design: 07/2000

TDR: 01/2001



7. Muon System Construction

The responsibility for the construction of the muon system will be shared between the collaborating institutes and should correspond to the financial contributions. All participating institutes have the right and the obligation to contribute to the various parts of the muon system as listed below. Details about the sharing of work for production will be agreed upon after the decisions on chamber technology and FE-electronics have been taken.


a) Chamber Construction

An extensive R&D program on various technologies is being carried out this year by the participating institutes. The results obtained from the beam tests will be the main input for the decision on chamber technology to be taken by the end of the year. The best technologies affordable will be chosen. This is in the interest of all participating institutes. A solution with similar technologies would be advantageous.


The following technologies are under consideration:

  1. CPC (for the inner part)
  2. WPC/WSC (for the outer part)
  3. TGC
  4. MRPC (for the outer part)
  5. Single or double gap RPC (for the outer part)


The following procedure for decision making has been adopted:

  1. Study the performance of each technology in beam tests with particular emphasis on the properties as given in the checklist (to be decided on by the end of this month)
  2. Preparation of LHCb notes summarizing the test beam results
  3. Discussion within the muon group, aiming at a recommendation by the group
  4. Refereeing of the notes by LHCb referees
  5. Final decision to be taken by the collaboration


Independent of the technology choice, several production centers should be setup. Institutes from Brazil, Italy and Russia will participate in the procurement of material for chamber construction, the quality control and the production. CERN will contribute to the definition of construction parameters and participate in the preparation of production lines.


b) FE-electronics

An engineer from Cagliari has started to work on the overall FE-electronics design for the muon system. He will take responsibility for coordinating the muon FE-electronics efforts in the future. Physicists and engineers from PNPI, Rome and UFRJ have also started to work on various aspects of the FE-electronics and wish to contribute to the design and production of components in the electronics chain.


Parts of the electronics chain:

1. FE-chip: - Three candidates are under consideration: ASD8-B (M. Newcomer et al., UPenn)

GaAs-chip (F. Giannini et al., Rome II) MAD4 (M. Pegoraro, Padova)

- Comparison of the chips and tests on the chambers will be carried out in

summer/autumn 1999

2. FE-board: - Design closely related to technology choice

3. OFF-Detector board: - Performs OR-logic and synchronization of signals

4. FEBI-board: - Contains L0- and L1- pipelines and serves as interface for the L0-muon

trigger. The design should be realized in close collaboration with the

muon trigger implementation.

5. Links: - Possibly LVDS from FE-board to OFF-detector board

- Possibly optical links from OFF-detector board to FEBI-board

c) Mechanics

- Overall support structure for muon filter: work will be carried out at CERN

- Overall support structure for chambers: work will be carried out at CERN

- Chamber support: interest in design and construction has been

expressed by Rome I




d) Service Systems

1. Gas System: - Design will be done at CERN

- Implementation will be the responsibility of the participating institutes

2. HV- and LV- systems: - Choice closely related to chamber technology and FE-electronics

3. Monitoring: - Slow Controls: (in close collaboration with JCOB group at CERN)

- Readout Chain: (in close collaboration with overall designers) - Trigger: (under responsibility of L0 implementation group)

4. Alignment



8. Assembling the Muon System

This should be done as a joint effort of all the collaborating institutes.