1. performance requirements technical specifications
CTA requirements
From
performance requirements to
technical specifications
German Hermann, Towards CTA specs Project Committee,

2. Towards “the optimal solution”
Science
Goals
Cost
Estimate
Require-
ments
System
Architecture
German Hermann, Towards CTA specs Project Committee,

3. Requirements and technical specifications
We (CTA) define our specifications by ourselves
customer = contractor
we better understand what we really need, and why …
German Hermann, Towards CTA specs Project Committee,

4. Towards “the optimal solution”
“Optimal solution” vs. development on finite time scale:
Let’s be pragmatic
Goal: enable prototyping of assemblies and sub- systems asap !
Parameters of prototypes as close a possible to final solution !
We need to create a consistent picture, fix requirements, narrow down parameter space and derive high level technical specifications
German Hermann, Towards CTA specs Project Committee,

5. Systems level definition
Proposal:
System :
The CTA observatory
Sub-systems:
Telescopes, array trigger, central DAQ-system, atmo-monitoring, …
Assemblies:
Cameras, telescope structures, reflectors, drive systems ….
Components:
PMTs, HV, Mirrors, calibration devices, actuators, motors ….
German Hermann, Towards CTA specs Project Committee,

6. Requirements levels Level 1: fundamental science requirements
Scientific mission
Duration, timeline
Cost
Schedule
Level 2 (A): observatory system requirements
Level 3 (B): Sub-system requirements
Level 4 (C): requirements on assemblies (structures, cameras, …)
Level (D): requirements on components
German Hermann, Towards CTA specs Project Committee,

7. Requirements: level 1 Level 1
Fundamental requirements of the observatory (as defined in 2005 LOI to ESFRI):
x 10 sensitivity in core energy regime (1-10 TeV)
~ x 1000 dynamic range in energy (some 10 GeV to 100s of TeV)
improved angular resolution (x 5)
Energy resolution
Large(r) gamma-ray field of view ,
full sky coverage: south: full energy coverage; north: emphasize on low energies
Cost envelope: 150 MEuro construction cost (as of 2005)
Schedule:
Operation cost: < 10 % per year (< ~ 5 %)
German Hermann, Towards CTA specs Project Committee,

8. First Draft Documents
German Hermann, Towards CTA specs Project Committee,

9. Draft/work material on Wiki
German Hermann, Towards CTA specs Project Committee,

10. Current “editing team”
SST: R. Canestrari, R. White
MST: B. Khelifi
LST: O. Blanch Bigas, Th. Schweizer
MC: J. Hinton, K. Bernloehr
R.Mirzoyan, P.Vincent, M. Panter, A. Foerster, M.Doro, C.Delgado
All of them can only spend a (very) small fraction of their time on that work
Still hell of a lot to be done
Team is clearly manpower (time) limited –
need ~2-3 persons working ~full-time, supported by WP coords
German Hermann, Towards CTA specs Project Committee,

11. Requirements vs techn. specs ?!
German Hermann, Towards CTA specs Project Committee,

12. Requirements vs techn. specs ?!
feasible ?!
Cost ?!
“Physicists”
“Engineers”
Requirement
Technical
Specifications (implementation dependent)
German Hermann, Towards CTA specs Project Committee,

13. Towards “the optimal solution”
Science
Goals
Cost
Estimate
Require-
ments
System
Architecture
German Hermann, Towards CTA specs Project Committee,

14. Towards “the optimal solution”
What are
the
science wishes ???
When can we expect feedback from prototyping projects ?
What is
technically
feasible
???
What is
affordable
???
German Hermann, Towards CTA specs Project Committee,

15. German Hermann, Towards CTA specs Project Committee, 2011-02-01