About us



Who are we?

Geant4 Associates International is a not-for-profit limited company registered at Companies House, United Kingdom. Geant4 Associates International is expert in the simulation of the interaction of particles with matter.
All the company directors are founding members of the Geant4 simulation toolkit and have been responsible leaders in the development and maintenance of the toolkit.

Profiles of Company Directors

John Allison
  • A director of Geant4 Associates International
  • A member of the Geant4 Collaboration since the start of the Geant4 toolkit development
  • Ex-spokesperson of Geant4
  • Ex-category coordinator of the Geant4 visualization group
  • Currently a member of the Geant4 Visualization Group
Katsuya Amako
  • A director of Geant4 Associates International
  • A member of the Geant4 Collaboration since the start of the Geant4 toolkit development
  • Ex-category coordinator of the Geant4 Tracking Group
  • Currently a member of the Geant4 Tracking Group
  • Currently the category coordinator of Geant4 Documentation Group
Michel Maire
  • A director of Geant4 Associates International
  • A member of the Geant4 Collaboration since the start of the Geant4 toolkit development
  • Ex-category coordinator of the Geant4 Electromagnetic Physics Group
  • Currently a member of the Geant4 Electromagnetic Physics Group
Laszlo Urban
  • A director of Geant4 Associates International
  • A member of the Geant4 Collaboration since the start of the Geant4 toolkit development
  • Currently a member of the Geant4 Electromagnetic Physics Group
Hajime Yoshida
  • A director of Geant4 Associates International
  • A member of the Geant4 Collaboration since the start of the Geant4 toolkit development
  • Ex-category coordinator of the Geant4 User Interface Group
  • Currently a member of the Geant4 User Interface Group

Company Registration

Geant4 Associates International is a not-for-profit limited company registered at Companies House, UK.:

  • Company Number: 6453274
  • VAT Registration Number: 979432078
  • Directors: John Allison, Katsuya Amako,  Michel Maire, Laszlo Urban and Hajime Yoshida.

Company Address

9 Royd Terrace, Hebden Bridge,

West Yorkshire, HX7 7BT, United Kingdom


Global History

Date Event
Oct. 2006 The original founders agreed to create the company during the 11th Geant4 Collaboration Workshop in Lisbon/Portugal.
Dec. 2007 Incorporation as a not-for-profit company in United Kingdom.
Mar. 2009 Approved by the European Space Agency (ESA) for eligibility to apply for ESA Invitations To Tender (ITT).
Aug. 2009 Established the first consultant contract with a UK security company.
Dec. 2009 A proposal in response to ESA ITT AO6014 approved. Our company is a member of the consortium which submitted the proposal.
Dec. 2009 Another proposal in response to the ESA ITT AO6049 approved. Our company is a member of the consortium which submitted the proposal.

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