The LHC interaction region repository provides a common framework for the construction of the Fluka geometry of the LHC interaction points. The repository includes a directory per each interaction region IR[X]. All the IR[X] directories have the same internal structure which is compatible with the Line Builder format.

The additional directory contains extra information and scripts for the configuration of interconnects, connection cryostats and beam loss monitors (BLMs).

The structure of the repository is the following:

 LHC/
  |
  +- IR[n]/                 
  ~               
  +- additionals/
     +- BLMs/ 
     +- COLLIMATORs/
     +- CONN_CRYOSTATs/
     +- INTERCONNECTS/
     `- layout.py 

Additionals

Enabling the BLMs

Four BLM additional files must be prepared before running the Line Builder:

• BLMs.B1.names.dat
• BLMs.B2.names.dat
• BLMs.B1.rotdefis.dat
• BLMs.B2.rotdefis.dat

The tools necessary for the creation of those files are in the LHC/additionals/BLMs directory.

BLM list generation

The first steps consists in selecting a detailed BLM list which should contain the name and the s coordinate of the BLMs. We provide a default file (BLM_DefaultList.dat) which contains a complete (but unmantained) list of the LHC BLMs.

A custom BLM list can be generated using the LHC layout page. The webpage generates xls files which will contain at most 2600 lines. For longer list we suggest to split the list in more files bu submitting different queries. The BLM list must be then manually saved as plain text. Only then it can be processed by the filter_columns_BLM_db.sh script which sorts and filters the columns.

Usage: filter_columns_BLM_db.sh [Layout_DB_output]

BLM Fluka files generation

The script create_beams.py creates the names and rotdefis files required for the correct placing of the monitors in the Fluka geometry.

Usage: create_beams.py [BLM_list_file] [from] [to]

Examples:

• IR7, right, sector 7 to 13 create_beams.py BLM_DefaultList.dat BLMQI.07R7.B2I30_MQ BLMQI.13R7.B1E30_MQ
• IR8, left, sector 7 to 4 create_beams.py BLM_DefaultList.dat BLMQI.07L8.B2I30_MQM BLMQI.04L8.B1E30_MQY

Including the BLM and IC files in the LineBuilder configuration files

The generated files must be included in the inputcard configuration file adding a line for each additional file as follows:

# [other auxiliary_file]       
# Names and position of the BLMs
auxiliary_file       : optics/myconfiguration/BLMs.B1.names.dat   1       a       0
auxiliary_file       : optics/myconfiguration/BLMs.B2.names.dat   2       a       0
# Names and position of the ICs
auxiliary_file       : optics/myconfiguration/IC.B1.dat           1       a       0
auxiliary_file       : optics/myConfiguration/IC.B2.dat           2       a       0
# Additional ROTDEFIs cards for the BLMs
rotdefi_file         : optics/myconfiguration/BLMs.B1.rotdefis.dat        1
rotdefi_file         : optics/myconfiguration/BLMs.B2.rotdefis.dat        2

NB: The order of auxiliary files matters

The BLM and IC prototypes must be added in the prototypes.lbp (if they are not yet present) as follows:

# - BLMs
# ---------------
BLM         BLM_BODY        0       0.0       0.0         -         0 0
ROT-DEFI         0.0      0.0       0.0   -1000.0    3000.0    2000.0 proto
#
# - Interconnects
# ---------------
# - Long interconnect
#ROT-DEFI         0.0       0.0       0.0       0.0    3000.0    2100.0 proto
#
# - Short interconnect
QBEI      ICs_BODY  0         0.0       0.0       -         0         0
QEQI      ICs_BODY  0         0.0       0.0       -         0         0
ROT-DEFI         0.0       0.0       0.0       0.0    3000.0    1900.0 proto
#
# - Intermediate interconnect
QQBI      ICx_BODY  0         0.0       0.0       -         0         0
QDBI      ICx_BODY  0         0.0       0.0       -         0         0
QBBI      ICx_BODY  0         0.0       0.0       -         0         0
QBQI      ICx_BODY  0         0.0       0.0       -         0         0
ROT-DEFI         0.0       0.0       0.0       0.0    3000.0    2000.0 proto
#
QDQI      ICx_BODY  0         0.0       0.0       -         0         0
#
QQEI      ICx_BODY  0         0.0       0.0       -         0         0
QEBI      ICx_BODY  0         0.0       0.0       -         0         0
QQDI      ICx_BODY  0         0.0       0.0       -         0         0
#
#

Further Readings

About LHC

• LHC-PM-QA-204-32-00.pdf: Quality Assurance Definition: Equipment Naming Conventions;
• LHC-C-QA-0002-10-00.pdf: Quality Assurance Definition: Naming of LHC Entities and Their Parameters for the CERN Control Centre

VittorioBoccone - 13-Sep-2011