710
D. Froidevaux
tracking detectors, number of cells in the electromagnetic calorimeter, overall
strength and uniformity of the magnetic field, etc.). The number of coils to
be constructed in the ATLAS superconducting toroid and the peak field of the
CMS central solenoid are two examples of early and fundamental parameters of
the experiments, which were studied for quite some time and had a significant
bearing on the overall cost of the experiments;
• some of the usual benefits of such an approach, such as optimised production
costs for repetitive manufacturing of the same product, are not there to be reaped
when considering the experiments as a whole rather than looking at individual
components, such as the micro-strip silicon modules, which number in many
thousands and did indeed benefit in many aspects from a systematic engineering
approach;
• the overall technological scope of these nascent experiments required creativity
and novel approaches in areas as far apart as 3D-calculations of magnetic fields
and forces over very large volumes containing sometimes unspecified amounts
of magnetic materials and radiation-dose and neutron-fluence calculations of
unprecedented complexity in our field to evaluate the survival of a variety
of objects, from the basic materials themselves to complex micro-electronics
circuits. Only a well-balanced mix of talented and dedicated designers, engineers
and physicists could have tackled such issues with any chance of success;
• the decision-making processes in our community cannot be too abrupt. Consensus needs to be built, especially between physicists but also between engineers
from sometimes widely different cultures and backgrounds.
In retrospect, however, there has emerged as a clear lesson, that the management
of the experiments should have evolved at an earlier stage the decision-making
process from a physicist-centric one at the beginning, when little was known about
the detailed design of all the components, to a more engineer-centric one, as the
details were fleshed out more and more. Establishing engineering envelopes and
assembly drawings for the different systems, routing the very large and diverse
amount of services needed to operate complex detectors distributed everywhere
across the available space, and designing, validating and procuring common
solutions for many of the electronics and controls components are examples, which
clearly illustrate this need. The collaborations have indeed encountered difficulties
to recognise such needs and to react to them at the appropriate moment in time.
16.2.3.3 International and Distributed: A Strength or a Weakness?
ATLAS and CMS are truly international and distributed collaborations, even if the
engineering and/or manufacturing of some of the major components of both experiments have been entrusted to large laboratories situated all across the world. Modern
technology (web access to document servers, video-conferencing facilities, more
uniform standards, such as the use of the metric system, for drawings, specifications
and quality assurance methods, electronic reporting tools) has been instrumental in
D. Froidevaux
tracking detectors, number of cells in the electromagnetic calorimeter, overall
strength and uniformity of the magnetic field, etc.). The number of coils to
be constructed in the ATLAS superconducting toroid and the peak field of the
CMS central solenoid are two examples of early and fundamental parameters of
the experiments, which were studied for quite some time and had a significant
bearing on the overall cost of the experiments;
• some of the usual benefits of such an approach, such as optimised production
costs for repetitive manufacturing of the same product, are not there to be reaped
when considering the experiments as a whole rather than looking at individual
components, such as the micro-strip silicon modules, which number in many
thousands and did indeed benefit in many aspects from a systematic engineering
approach;
• the overall technological scope of these nascent experiments required creativity
and novel approaches in areas as far apart as 3D-calculations of magnetic fields
and forces over very large volumes containing sometimes unspecified amounts
of magnetic materials and radiation-dose and neutron-fluence calculations of
unprecedented complexity in our field to evaluate the survival of a variety
of objects, from the basic materials themselves to complex micro-electronics
circuits. Only a well-balanced mix of talented and dedicated designers, engineers
and physicists could have tackled such issues with any chance of success;
• the decision-making processes in our community cannot be too abrupt. Consensus needs to be built, especially between physicists but also between engineers
from sometimes widely different cultures and backgrounds.
In retrospect, however, there has emerged as a clear lesson, that the management
of the experiments should have evolved at an earlier stage the decision-making
process from a physicist-centric one at the beginning, when little was known about
the detailed design of all the components, to a more engineer-centric one, as the
details were fleshed out more and more. Establishing engineering envelopes and
assembly drawings for the different systems, routing the very large and diverse
amount of services needed to operate complex detectors distributed everywhere
across the available space, and designing, validating and procuring common
solutions for many of the electronics and controls components are examples, which
clearly illustrate this need. The collaborations have indeed encountered difficulties
to recognise such needs and to react to them at the appropriate moment in time.
16.2.3.3 International and Distributed: A Strength or a Weakness?
ATLAS and CMS are truly international and distributed collaborations, even if the
engineering and/or manufacturing of some of the major components of both experiments have been entrusted to large laboratories situated all across the world. Modern
technology (web access to document servers, video-conferencing facilities, more
uniform standards, such as the use of the metric system, for drawings, specifications
and quality assurance methods, electronic reporting tools) has been instrumental in