\ ALICE physics tasks v04.docx
ALICE physics and machine characterisation
Research areas, experiments & tasks
Period 12 (2011)
v.06
Reviewed October 2011.
 Removing redundant tasks in Yuri’s old table
 Plan for remaining shifts in period 12.
Machine characterisation and diagnostics are more ‘specific’ tasks that will support (and are
driven by) AP Studies.
Transverse model + comparison with data. Injector(post booster) + Linac. Quad Scans.
Andy, James, Yuri, Frank.
- Analyse quad scan data to measure beam Twiss and then input to model
- Resolve discrepancies between model and further measurements.
- Take more data? ST1 has been taken and analysed. More quad scans in other parts of
machine (1-2 shifts) ?
Longitudinal model. Injector(post booster) + Linac. (THz, Streak camera, EO
measurements; Bunch length/energy spread measurements in injector/post linac). Requires
simulation for understanding. Frank, Peter, Julian, Deepa.
Some tasks:
- Evaluate bunch length/energy spread in injector and post-linac (discrepancy?)
- Validate the zero-cross bunch length measurement with simulation.
- R56 measurements with diagnostics.
- Diagnostics (EO/THz, Streak Camera, TOA)
- More scans within one shift vs buncher power, vs BC1 phase
- Post linac EMI-1 studies. (2-3 shifts)
Injector (especially pre-booster) special case deserving individual attention. Dynamics may
be highly complicated and difficult to disentangle with limited diagnostics. Simulation
effort?
- A new injector optimisation/parameter scans for our current parameter set?
Frank/Julian/Bruno
Beam orbit correction (+ supporting BPM characterisation). James, Frank.
Two beams. Yuri?
#
Machine characterisation and diagnostics
1.01 BPMs
 Experiments and data analysis
 Communications with diagnostic group
Tests of EMMA BPM electronics on ALICE

Modified Faraday Cup electronics

RF Phase stability
 Understanding sources of instability
 Detailed schematic
Who
Frank
Ben
Alex K.
Ian K.
Frank
Alex K.
Yuri
Luis
Yuri
Lee
When & Comments
\ ALICE physics tasks v04.docx
 Improvements in phase stability (RF/ PI laser)
BLM system
 Communication with RF group
 Planning and conducting tests/experiments
 Setting rules for ALICE operation with BLM
 BLM as a diagnostic tool
 Assist in “training” ALICE team on BLM related issues
Effect of phases & GS change (buncher,BC,LC) on beam
 to simulate non-ideal setups and phase drifts.
 Exps for models developments
 Cresting method using beam loading
 First – LC, then BC
 (Q ~ 5-10pC and 40-80pC );
 cross-check with usual method
 possibility for automation ?
Dispersion measurements
 INJ-5; AR1-1; AR2-1, ST2-3, EMI-1 (low Q ~ 1pC)
Automated emittance measurement tool (Ben’s
programme)
 Assess, verify and “commission”
Automated emittance and Twiss measurements
programme (James)
 Fully tested against “manual” measurements
 User friendly and reliable
 k(E): x = k I at var E
 INJ-5 and others where re-construction of spectra from
several images required
 Beam energies as per standard setups requirements
Beam based calibration of phase shifters
 To cross-check RF calibrations
Luis
Yuri
Yuri
Peter
James
Yuri
Yuri
Ben
Deepa
James
Deepa
Yuri
---
General strategy & “maintenance”

FEL setup characterisation and development
 mostly, in terms of longitudinal parameters
 optimisation
THz setup characterisation and development
 mostly, in terms of longitudinal parameters
 optimisation
 optimisation in terms of “good” THz generation
 assisting in THz transport to diagnostic room
 THz characterisation
Yuri
Transverse emittance
 Measure the emittance at 60pC
 Assessment and consolidation of previous data
 Experiments and measurements
 Compare different methods; make them consistent with
each other
 Part of setups characterisation
 Emittance v SQRT(Buncher power)
ALICE models : optics
 Online model
 Matching model and real life
 Planning and conducting experiments, data analysis
Deepa
Yuri
James
?
?
James
Peter
\ ALICE physics tasks v04.docx
ALICE models : longitudinal dynamics
 ASTRA, GPT
Longitudinal dynamics: experiments
 Bunch length measurements with zero-phase technique at
low beam energies
 Understanding dynamics from booster to linac
Ad hoc modelling
 To support analysis of experimental data
Sextupoles
 In general : what the hell is going on with them !
 Polarity ?
 ST2/3 images at var SEXTs fields
 Effects on FEL and THz
Streak camera
 Experiments, ....
Response matrix studies

Frank
Julian
Bruno
Yuri
Frank
Frank
Julian
James
Deepa
Peter
James
James
Machine optimisation for “good” THz
 Facilitate THz transport to Diagn. Room
EMMA studies
 AP person to work on EMMA
“Energy modulation by THz” related studies
Setups for energy modulation by THz experiment
 Q~20pC
 Q~1pC
 min E, min z, specific optic functions at IP and chicane
 characterisation
AP support for “laser modulation” experiments

Generic
James
Yuri
James
CI team
Yuri
James
FJ - Too vague ?