1. A Virtual Implementation of VELA (CLARA)
Duncan Scott, Tim Price, Rory Clarke

2. Design Goals / Specification
A virtual implementation of all the parts of VELA (CLARA) required for Physics simulations
Self-contained ‘out-of-the-box’ package, that ‘just works’
Individual Local Copies
Seamless integration with existing tools
Hardware Controllers, VELA EPICS PVs

3. Example Uses Prototyping Control Room Applications
High Level Software Development from your office / living room etc. on machine you can’t break and is always available
Online machine set-up
Moving from one machine state to another
Virtual Experiments
Finding user required set-ups
ANY OTHERS?

4. Current Status / Open Questions
VELA Hardware Controller
Mainly exist, Python / c++ modules
Is it a priority to extend the source to other languages? hopefully not… ;-)
Data saving?
Online Model (Bruno’s ASTRA simulation)
Finding the correct ASTRA parameters
Integrate and continue Model Validation project
How do we ‘chunk’ it?
Speed: gun simulations are slow…
Implement Pre-computed set-ups (especially gun)
Future integration with other codes / Magical Project Data-bases?
Incorporate latest ‘real-word’ data, lattice decs etc.

5. Current Status / Open Questions
Virtual Environment
Virtual Linux containing a version of EPICS with all relevant process variables
What do we need? Magnets, RF phase / amp, BPMs screens … ?
All accessible though same Hardware Controllers as real machine
ASTRA model sits in virtual environment
A ‘Manager’ interface handles the EPICS / ASTRA interface,

6. EPICS provides a common control interface and interlocks between the hardware and the user. Its communication layer is via Process Variables (PVs). The user can set and read to these PVs of which there may be thousands.
VELA’s magnets and interlocks have been taken as a model and converted into a simulation. This EPICS simulation is running on a virtual machine.
We have to be careful to follow a naming convention with the simulation PVs that follows a different syntax than the real machine’s PVs to avoid clashes.
EPICS VM 5A
Noise and ramping current have been added to the simulation of the virtual magnets.
Noise is adjustable. Here it is about 5%
Amps
Time

7. Structure for ‘Real’ VELA
epics
VELA
IOCs that exit on real machine
Hardware components
Machine
Hardware Controllers
Hardware Controllers
User GUI 1
User GUI 2

8. Structure for Virtual VELA
epics
manager
model
IOCs
(mimic real VELA)
Python script
ASTRA
Virtual Linux
Hardware Controllers
User Computer
(desktop PC)
User GUI

9. (EPICS) RF Amp. to ASTRA Gun Gradient:
Manager
Conversions
(EPICS) RF Amp. to ASTRA Gun Gradient:
beam_momentum [MeV/c] = * gun_gradient [MV/m] (on crest)
(Some work Frank did, see wiki ‘Gun’ page)
Gradient = Amp÷29.016
For example: ÷ ~ 62 MV / m gives 4.5 MeV / c
This is rough as record beam setup in the past has not been sufficient to get a strong relationship.
Current to K Value:
I = Current of magnet [A] (Set to and read from epics)
p = momentum [MeV][c] (calculated before simulating path through quads)
L = Magnetic Length [mm]
a = Intercept [T] predefined values from excel spreadsheet (value contained in python script)
m = Gradient [T][A] (

10. Current VM Functionality
Set QUAD currents
Monitor QUAD currents
Run ASTRA from ‘outside’ Virtual Machine
Convert ASTRA distributions into ‘x’ and ‘y’ signal for BPMs
Example GUIs monitoring EPICS PVs

11. Future: Plan for VM More EPICS parameters in VM Screens:
Magnet polarity switches, cameras, BPMS, etc.
Screens:
ability to output ASTRA distribution as EPICs PV
moments, or ‘fake’ images using the moments
Use predefined distributions instead of run simulation through Gun each time.
ASTA simulation database
Dipoles?
Include more sections of VELA ?

12. Future: Plan for your applications
Area Leaders Plan their own Applications on paper. E.g.
GUI layout
Procedures (set-up, what to scan, what DAQ etc)
Analysis
Data saving
Discuss application with TP / DJS etc (maybe in this meeting)
Decide who will be responsible for which parts
Prototyping and development
Requires toolset installed: Python, VM, Hardware Controllers,
Go through some worked examples of GUI building etc.