1. 05/05/2004Cyrille Thomas DIAMOND Storage Ring Optical and X-ray Diagnostics

2. 05/05/2004Cyrille Thomas I. Introduction to DIAMOND II. Visible diagnostics lines III. X-ray diagnostics lines - Streak camera - Multi-channel analyser - X-ray pinhole camera

3. 05/05/2004Cyrille Thomas 25 March 2004 Ø 17 8.3 m Storage ring 3 GeV (comm. Jan. 2006) 48 potential beamlines LINAC (comm. May 2005)  100 MeV Booster  0.1 – 3 GeV

4. 05/05/2004Cyrille Thomas 25 March 2004

5. 05/05/2004Cyrille Thomas Principal parametersValue Electron beam energy (GeV)3 Number of potential beam lines48 Electron beam current (mA)300 (500) Overall circumference (m)561.6 Revolution Frequency (kHz)534.18 Electron bunch Longitudinal r.m.s size10 ps  3 mm Transverse r.m.s size (  m) (in BM) 50 (H), 25 (V) Emittance (nm rad)2.7 Synchrotron radiation Power (W / mrad) (in Bend. Mag.)80 Divergence (  rad) 130

6. 05/05/2004Cyrille Thomas 1 - Imaging transverse and longitudinal beam 2 - Analysis of the image  beam characteristics Transverse axis: 2 X-ray pinhole cameras: emittance, energy spread 1 visible CCD camera: watching the beam Longitudinal axis: Streak camera: bunch long. distribution, analysis of long. instabilities Collimator + multi-channel analyser: purity of the buckets The optical Diagnostics Photodiode + oscilloscope and / or spectrum analyser

7. 05/05/2004Cyrille Thomas Location BM 1, ID 1 + hutch (prefab.) for the optical lab. (40 m 2 )  streak camera  CCD, Bunch purity, etc. Two bending magnets

8. 05/05/2004Cyrille Thomas Dipole 2 (BM 1):  X-ray pinhole camera  Visible light  optical hutch Streak camera CCD camera Collimator + Multi-channel analyser Dipole 1 (ID 1)  X-ray pinhole camera Photodiode + fast oscilloscope / spectrum analyser

9. 05/05/2004Cyrille Thomas Beam characteristics at the source points in BM 1 and ID 1 Time domain Transverse plane Tp Tt T Pulse length   = 10 ps Time inter pulse, Tp = 2 ns Pulse train duration, Tt = 1.248  s Revolution period, T= 1.872  s emittance  = 2.7 nm rad relative energy spread    = 0.001  x = 50  m  y = 25  m xx yy

10. 05/05/2004Cyrille Thomas 1.5 m 3 m Visible S.R. from Dipole 2 CCD S.C. PMT + MCA S.C. : Streak camera PMT : Photo multiplier tube Power meter O.D. : graduated optical density O.D. S: remote controlled shutter S collimator Computer MCA : Multi-channel analyser

11. 05/05/2004Cyrille Thomas Streak camera Electron bunch longitudinal distribution, f  Evolution Bunch length ( ) Bunch centroid ( )  Broad band impedance: f ≡ f (Z n /n)

12. 05/05/2004Cyrille Thomas Streak camera - fast sweep at 250 MHz sweep range: 175 - 1200 ps - slow sweep sweep range: 20 ns - 70 ms - ‘firewire’ CCD camera software solution for acquisition > 70 ms

13. 05/05/2004Cyrille Thomas Bunch purity measurement  Statistical distribution of electrons in the ring SR N. dens. Coll. PMT MCA PC 10 15 Ph / s 4.2  10 6 Ph / s = 8 Ph / turn Resolution: 32 ps / channel Number of channels > 15 bits (32768) Memory > 20 bits / channel (10 6 )

14. 05/05/2004Cyrille Thomas X-ray pinhole camera Firewire CCD Pinhole (25  m 2 ) Al (3 mm) Cu 45 W 1 W Lens 10 mW screen d = 4 mD = 8 m (outside vacuum) Magnification  2 G. Rehm – Acquisition of diagnostic screen and synchrotron radiation images using IEEE 1394 digital cameras - Poster - 0.8 °

15. 05/05/2004Cyrille Thomas Photon counting:  10 10 photons / s @ > 15 keV Number of photons / pixel: Image Size (3  ) 300  150  m 2  ≈ 20 Ph / ms @ 1 mA Pixel size: 10  10  m 2 Energy conversion rate: 10 %  ≈ 10  10 3 Ph / ms @ 500 mA On the screen On the CCD

16. 05/05/2004Cyrille Thomas Size of the photon beam in Dipole 1 and 2 vs. relative energy spread  ’, and  known D = 8 m d = 4 m

17. 05/05/2004Cyrille Thomas Accuracy of the measurement centrer.m.s values Error        0.010.0020.0010.0350.034 0.050.0030.0130.1640.181 0.10.0670.0600.3870.358 Computed accuracy: 1.Generate set of distributions of Twiss parameters 2.Generate a set of photon beam sizes on the screen, assuming   and   3.Fit the sizes with the nominal Twiss parameters 4.Find a distribution set of emittances and relative energy spread  retrieve the centre and the standard deviation of the distributions

18. 05/05/2004Cyrille Thomas Conclusion A set of optical measurements to diagnose the quality of the DIAMOND electron beam has been designed.  Streak camera images: bunch length, bunch centroid, impedance  X-ray pinhole camera: transverse sizes, emittance, energy spread 6-dimensional phase space: Electron bunch train quality:  Multi-channel analyser with 32 ps resolution, 10 6 dynamical resolution