Elettra parameters

Elettra is operated 24 hours/day, 7 days/week for some weeks followed by periods of intermission mostly dedicated to maintenance. These operation periods are called "Runs". Beamtime is allocated in "shifts" of 8 hours which are divided in Morning (M) from 07:00 a.m to 15:00, Late (L) from 15:00 to 23:00 and Night (N) from 23:00 to 07:00. Some beamtime is reserved to Machine Physics studies but most of it is allocated to users for measurements activities at the beamlines.

Elettra is usually operated at two different energies 2 GeV and 2.4 GeV.

Details on:

can be found at the operating schedule link.

You can check the ring present status at the link machine status and also have a look at its operating parameters and conditions.

ODAC is the acronym of the project: Operations and Development of the Accelerators.

Operating Conditions
Energy range 0.75 – 2.5 GeV
Injection Energy All energies up to 2.5 GeV
User Operating Energy 2.0 GeV (75% of user time)
2.4 GeV (25% of user time)
1.0 GeV (SR-FEL)
Operating mode Top-up
Operating current (user request) 300 mA at 2.0 GeV (lifetime 26 h)
140 mA at 2.4 GeV (lifetime 40 h)
Top-up injection rate 1 mA every 6 min at 2.0 GeV
1 mA every 20 min at 2.4 GeV
Filling pattern Any (single, few, multi etc.); most requested multibunch filled at 95% of the ring circumference (864 ns) and hybrid ( multibunch with a single bunch in the dark gap )
Bucket size (bunch to bunch distance in multi-bunch) 2 ns
Dark gap when fill at 95% 43 ns
Operating details Long Lifetime - Instability Free
(multi-bunch and orbit fast Feedbacks and super-conducting 3rd harmonic cavity operating) Id gap/current control to the users

The latter has been concepually designed to have a low emittance of 4.0 nm and 7.1 nm, at 1.5 and 2.0 GeV respectively. The lattice is of the expanded Chasman-Green type composed of twelve double bend achromats with  horizontal and vertical tunes of 14.3 and 8.2. The beta functions are 8.2 m horizontally and 2.6 m vertically in the center of the dispersive free straights, and the maximum dispersion is 0.4 m. Two families of sextupoles have been placed in the dispersive arcs in order to compensate for the large horizontal and vertical horizontal and a vertical natural chromaticities of -43.0 and of -14.0. An additional harmonic sextupole family islocated in the non-dispersive straights, has been optimize to minimize non-linear effects and to enlargen the dynamic aperture.
Insertion devices are accomodated in eleven of the straight sections, where additional quadrupole families are used for linear distorsion compensations.

Elettra Parameters

Beam energy [GeV]   2 2.4
Storage ring circumference [m] 259.2    
Beam height in experimental area [m] 1.3    
Number of achromats 12    
Length of Insertion Device (ID) straight sections [m] 6(4.8 utilizabile per ID's)    
Number of straight sections of use for ID's 11    
Number of bending magnet source points 12    
Beam revolution frequency [MHz] 1.157    
Number of circulating electron bunches 1 - 432    
Time between bunches [ns] 864 - 2    
Tunes: horizontal/vertical 14.3/8.2    
Natural emittance [nm-rad]   7 9.7
Energy lost per turn without ID's [keV]   255.7 533
Maximum energy lost per turn with ID's [keV] (all)   315 618.5
Critical energy [keV]   3.2 5.5
Bending magnet field [T]   1.2 1.45
Geometrical emittance coupling % £ 1%    
Spurious dispersion (at the centre of IDs): horizontal (rms max/min) [cm] 6/2.    
Spurious dispersion (at the centre of IDs): vertical (rms max/min) [cm] 2/0.5    
Injected current [mA]   320 150
Machine dominated by the Touschek effect      
Energy spread (rms) %   0.08 0.12
Lifetime [h] (natural)
Lifetime [h] (with 3rd harmonic cavity)
Bunch length (1 σ) [mm]*   5.4 7
Beam dimensions (1 σ)*      
ID source point - horizontal/vertical [µm]   241/15 283/16
Bending magnet source point - horizontal/vertical [µm]   139/28 197/30
Beam divergence (1 σ)*      
ID source point - horizontal/vertical [µrad]   29/6. 35/8.
Bending magnet source point - horizontal/vertical [µrad]   263/9 370/13

The values shown (taking into account the energy spread) are averages, obtained from a consideration of different angle and position values of the spurious dispersion and can vary by ±10%

Booster Parameters

Magnet lattice 2 fold symmetry
Injection/Extraction energy [GeV] 0.1 - 2.5
Repetition frequency [Hz] 3.125
Nominal beam current
  • multi-bunch/pulse lenght
  • single-bunch/pulse lenght     

RF frequency operation [MHz]

499.646 - 499.654

Circumference [m] 118.8
Revolution period [ns] 396
Harmonic number 198
Equilibrium emittance @ 2.5GeV
  • nominal emittance optics [m rad]
  • low emittance optics [m rad]

r.m.s. energy spread @ 2.5GeV 7.18*10-4
Energy loss per turn @ 2.5GeV 388keV
Damping times Tx, Ty, Tz @ 2.5GeV 5.1, 5.1, 2.6ms
Betatron tunes Qx, Qy
  • nominal emittance optics
  • low emittance optics

5.39, 3.42
6.80, 2.85
Natural chromaticity Cx, Cy
  • nominal emittance optics
  • low emittance optics

-6.6, -4.7
-11.1, -5.2
Momentum compaction factor
  • nominal emittance optics
  • low emittance optics

Maximum ßx, ßy, Dx [m]
  • nominal emittance optics
  • low emittance optics

10.8, 13.8, 1.624
15, 17.2, 1.683
Peak effective RF voltage (Tq~60s)
  • nominal emittance optics
  • low emittance optics

Ultima modifica il Lunedì, 26 Ottobre 2020 15:24