# Presentation: 329903

## Large International Collaborations

**The ATLAS Experiment **
**under construction at the **
**Large Hadron Collider at the**
**CERN lab in Geneva, Switzerland**
**has:**
**2000 physicists**
**from 34 countries**

## From the award-winning ATLAS movie

**From the award-winning ATLAS movie**

## Tabletop experiment

**to measure 1/r****2**** for **
**gravity at very small **
**distances, ...**
**a test for extra **
**dimensions.**
**Torsion Pendulum**

## barrel cryostat

## Slide 5

## Looking down 

**Looking down **
**the shaft to **
**the pit (cavern)**

## Toroid Magnet

**Toroid Magnet**

## Toroid Magnet

**Toroid Magnet**

## End cap 

**End cap **
**toroid magnet**
**structure**

## barrel cryostat

**barrel cryostat**

## muon

**muon**
**big**
**wheel**
**octant**

## sct

**sct**

**SCT =**
**Semiconductor**
**Tracker**

## SCT = Semiconductor

**SCT = Semiconductor**
**            ****Tracker**

## TRT = Transition Radiation Tracker

**TRT = Transition Radiation Tracker**

## The ATLAS Experiment has:

**2000 physicists from 34 countries**
**Designing and building ATLAS - 7000 tons of high-technology**
**equipment ­ involves more than just following a sheet of**
**instructions.**
**Scientists have to work together as a team while remaining**
**thousands of miles apart.**

## What is the balance between individual creativity 

**and being part of such a large collaboration?**
**The successful design and construction of a large and complex**
**state-of-the-art detector requires the creative participation**
**of many people. It is not the collaboration that is creative,**
**but the sum of its individual members.**
**   ****There are many subsystems, so that people mostly work in**
**small groups, contributing creatively. Ensuring that all**
**systems fit and work together, and are affordable, constrains**
**the creative process, but good ideas find a way.**

## How are important decisions made? 

**How are individuals heard?**
**Many important decisions involve just one or two subsystems. **
**They are discussed initially in the subsystem meetings, **
**where everybody can participate and make their voices heard.**
**Recommendations are then discussed in the ATLAS Executive**
**Board, and presented in plenary meetings which play a primary**
**role in forming a consensus when decisions are required.**
**   ****The leadership can only "lead" the collaboration to**
**decisions which are understandable to all, or at least to a**
**large majority.**
**   ****There is a clear sequence of steps from subsystem to**
**systems, with the vote by the Collaboration Board being the**
**ultimate step for major decisions.**

## How is such a large and far-flung collaboration 

**managed?**
**Each subsystem has its own management team. At the same time,**
**the Executive Board and Spokesperson maintain general**
**oversight.**
**   ****The Technical Coordination team is responsible for making**
**sure that all subsystems fit together. In parallel, there are**
**national representatives who monitor the use of resources from**
**their respective countries and make sure they are well used.**
**    ****Finally, direct contacts between individuals and teams with**
**the collaboration management also play an important role.**

## How do 2000 people communicate among 

**themselves? **
**How do you bridge large distances and overcome **
**time differences?**
**Electronic communication (e-mail, Web, telephone, video**
**conferencing) is obviously very important. However, regular**
**direct human contacts are crucial. Meetings play a significant**
**role.**

## How are tasks apportioned?

**By trying to match the interests and resources of the**
**participating teams to the tasks. This can succeed only if**
**everyone is also willing to share the less interesting but**
**necessary tasks such as building support structures,**
**contributing to buying cables, writing utility software**
**etc. **
**   ****This works because the physicists are motivated by the**
**prospect of exciting results, which depend on having a**
**complete, working detector system. Of course it is not always**
**easy to arrive at an optimal task-sharing to everyone's**
**satisfaction, with all tasks assigned.**

## How are the costs apportioned?

**There is no absolute formula. Large teams from wealthy**
**countries are expected to carry a larger share of the costs**
**than small teams from countries with developing**
**economies. Matching the possible contributions of teams and**
**countries to the overall effort is a central part of forming**
**the collaboration.**

## Where does the money come from?

**Mostly from the funding agencies of the various participating**
**countries. There are also significant contributions from CERN,**
**and some resources from individual universities.**

## How do people join?

**Teams interested in ATLAS may contact the Spokesperson, and**
**their interest is then brought to the attention of the**
**Collaboration Board (CB). After examining their resources,**
**their potential share of the work, their relationships with**
**other teams already working on ATLAS etc, the CB votes on their**
**admission.**

## How do you ensure that all the detector pieces 

**fit together?**
**The Technical Coordinator, supported by the Technical**
**Coordination Team, works with all the subsystem groups to**
**ensure that the separate pieces will fit together without**
**interfering with each other, and that the full detector can be**
**assembled.**

## How will data analysis be shared among 

**2000 people?****  **
**The data will provide input for many separate research**
**topics. ATLAS scientists will pursue these research areas**
**mostly in small groups working at their home institutions. All**
**collaborators will be invited to analyze the data by being part**
**of analysis teams.**
**   ****In some respects data analysis by individual ATLAS**
**physicists can be compared to data analysis by astronomers**
**using the Hubble Space Telescope. In both cases, scientists**
**choose the research areas and data that interest them most.**

## Analysis of Data 

**Analysis of Data **
**will take place **
**around the world**

## How does a collaborator get credit for 

**his/her contributions?**
**This is of course a major question. Internal publications**
**within the collaboration, usually with one or a few authors,**
**will document individual contributions. These can be made known**
**to the whole scientific community. Also, leading contributions**
**are often recognized by asking the person to speak at**
**conferences. **
**   ****However, the large collaborations still have to learn how to**
**handle this question. Major results are obtained collectively,**
**because people are willing to share the tasks. It is not only**
**the final analysis which counts, but all the work which makes**
**it possible to collect the data, and calibrate and prepare it**
**for final analysis.**

## What is the impact of the global spread of the collaboration?

**How does one contribute from 6000 miles away?**
**The global spread implies that factors such as transport of**
**components need to be taken into account during the**
**construction, and that communication logistics play a major**
**role. Full information, eventually including data analysis,**
**must be available simultaneously all over the**
**world. **
**   ****Nevertheless, it also implies that scientists from outside**
**Europe have to travel long distances to participate in**
**discussions and meetings, in the detector assembly and testing,**
**and eventually in the operation of the experiment. They may**
**have to spend extended periods away from their homes and home**
**institutions.**
**   ****However, all ATLAS scientists are after the same goal of**
**doing frontline physics, and are therefore willing to**
**endure these inconveniences to achieve that goal.  **