The ESS accelerator division is responsible for the requirements for all systems for the accelerator and assures that core know-how for the full system is secured at ESS. External collaboration partners will do the major part of the design update work and a large part of the construction. They are operating with a collaboration guided by a collaboration agreement and with individual contracts for each collaborator with significant work at ESS. The accelerator division has at present five groups and a management team. The groups are presently

1. Management 
2. Beam physics
3. Vacuums and cryogenics
4. RF systems
5. Beam Diagnostics
6. Control systems