A FEL for Mari X Beam dynamics Mari

A FEL for Mari. X Beam dynamics Mari. X team Particularly warm thanks to Simone Di. Mitri (FERMI-Elettra) whose selfless help permitted us to save al least one month of work

Our last working points didn’t completely satisfy the user’s desires. We had: e-E=2. 4 Ge. V lw=0. 7 cm with =2. 5 Å Users would also like: • Wavelength down to 1 Å • Flux at least 108 -1010 photons per shot • Coherence transverse and longitudinal With our parameters, reaching l=1 Å seemed a mission impossible

A Midwinter Night's Dream 3. 8 Ge. V ?

The bubble arc compressor 3. 2 -3. 8 Ge. V 3. -3. 6 Ge. V 1. 5 -1. 8 Ge. V

In this way, we can avoid the dangerous road of the Radia. Beam, not tested, undulator…

m 5 m . . and use the KYMA p=7. 82 mm undulators, already tested. Ciocci et al. , 2015 SPIE lw=14 mm Gap=5 mm B=1 -1. 1 T aw=0. 7 -0. 8 KYMA guaranties an immediate upgrade with similar performances at lw=12 -10 mm We can also have a variable gap! 4 mm

What could we do with E<3. 8 Ge. V ? Much. Period 12 mm 10 mm 7 mm Gap B peak aw (mm) 5 0. 7 T 0. 6 3 1. 0 T 0. 87 gamma e-Energy Wavelength Ph-energy 6262 3. 2 Ge. V 3. 2 Ge. V 2. 08 A 2. 68 A 6 ke. V 4. 66 ke. V 5 3 5 3 1. 9 0. 7 T 1. 0 T 0. 4 T 0. 9 T 1. 1 T 0. 6 0. 87 0. 2628 0. 591 0. 262 0. 506 7436 6262 3. 8 Ge. V 3. 2 Ge. V 3. 8 Ge. V 1. 51 Ge. V 1. 47 A 1. 9 A 1. 47 A 1. 72 A 0. 96 A 1. 22 A 1. 12 A 8. 5 ke. V 6. 57 ke. V 8. 5 ke. V 7. 25 ke. V 13 ke. V 10 ke. V 11 ke. V 1. 9 1. 1 T 0. 506 7436 2. 14 Ge. V 0. 79 A 15. 82 ke. V

One undulator lw=1 cm, no delay line Ph energy 4. 5 -13 ke. V lamda(m) Ph energy (ke. V)(m) Arc working regime ? Lamda 1 Å-3 Å Lamda_w=1 cm aw=0. 26 -0. 7

Now we can go down with wavelength, but what about the larger ones? Possibilities: a) Or lowering the electron energy by means of beam dynamics solutions, with insertion elements after the arc. b) Or foreseeing a second undulator with larger period. c) Or both.

Ph energy 1. 7 -13 ke. V lamda(m) Ph energy (ke. V)(m) One undulator lw=1 cm, delay line Lamda 1 Å-7 Å Arc+delay line working regime ?

Ph energy 0. 3 -3 ke. V Ph energy 4. 5 -13 ke. V lamda(m) Ph energy (ke. V)(m) Two undulators lw=1 cm and lw=3 cm Lamda 5 A-4 nm Lamda 1 Å-3 Å Arc working regime Lamda_w=3 cm aw=0. 6 -2. 5 Lamda_w=1 cm aw=0. 26 -0. 7 Und 2 Und 1

Ph energy 0. 3 -3 ke. V Ph energy 4. 5 -13 ke. V lamda(m) Ph energy (ke. V)(m) Two undulators lw=1 cm and lw=3 cm Lamda 5 A-4 nm Lamda 1 Å-3 Å Arc working regime Lamda_w=3 cm aw=0. 6 -2. 5 Lamda_w=1 cm aw=0. 26 -0. 7 Und 2 Und 1

Ph energy 0. 1 -13 ke. V lamda(m) Ph energy (ke. V)(m) Two undulators lw=1 cm and lw=3 cm, =3 cm delay line Lamda 1 A-11 nm Arc+delay line working regime ?

FEL 3 -d simulations made with Genesis 1. 3 (Thanks, Sven!) Ideal electron beam. Maximum precision prescriptions (compatibly with lap top simulation). Spanning the maximum number of parameters (compatibly with short time had).

Electron beam and undulators Gaussian distributions Two undulators Charge from 6 to 50 p. C Current 2 k. A Low energy operation: lw=3 cm aw=1 -2. 5 L=25 m Rms Length from 1 to 3 um (3 - 10 fs) Emittance from 0. 4 to 0. 7 um Energy spread from 1 x 10 -4 to 5 x 10 -4 High energy operation: lw=1 cm aw=0. 3 -0. 6 L=60 m

Example 1: water window (3 nm), large period und. FEL Mari. X FERMI Eu. Sparc e-En (Ge. V) 2. 5 1 Und l_w, L(cm, m) 3 , 25 5, 1. 5 , 30 Ph-en (ke. V) 0. 45 (2. 8 nm) 0. 38 (4 nm) 0. 45 Rep rate 1 MHz 10 -50 Hz 10 -100 Hz Energy 8 -16 u. J 5 -10 u. J 10 -80 u. J Numb per shot 3 -7 10^11 <10^12 Bandwidth (%) 0. 1 0. 02 -0. 07 0. 1 N/ s (s-1) 2 -7 10^17 5 10^12 <10^14 Spectral dens(N/shot/%bw) 3 -7 10^12 5 10^12 <10^13 Tot. spect dens. (N/s/%bw) 2 -7 10^18 2. 5 10^14 <10^15 Coherence Sin. Spike Full Sin. Spike Q=8 -16 p. C, I=2 k. A, emit=0. 5 um DE/E=2 10^-4, a_w=2. 5, dt=2 -3. 5 fs Growth Spectrum 20 m Power 20 m

Example 2: linear spectroscopy (2. 9 Å), short per. und FEL Mari. X LCLS II Q=8 p. C, I=2 k. A, emit=0. 4 um DE/E=2 10^-4, a_w=0. 6, dt=2 fs e-En (Ge. V) 2. 5 Und l_w, L(cm, m) 1 Ph-en (ke. V) 4. 1 ke. V 1 -7 ke. V Rep rate 1 MHz 60 Growth Energy Numb per shot 10^12 -10^13 Bandwidth (%) Spectrum 60 m N/ s (s-1) Spectral dens(N/shot/%bw) Power 60 m Tot. spect dens. (N/s/%bw) Coherence Single spike

Example 3: single shot imaging (1. 2 Å), short per. und FEL Mari. X LCLS e-En (Ge. V) 3. 8 3 Und (cm, m) 1 60 3 Ph-en (ke. V) 10. 16 25 Rep rate 1 MHz 120 Hz Energy 27. 5 u. J 1 -5 m. J Numb per shot 1. 7 10^10 10^12 Bandwidth (%) 0. 12 0. 1 N/ s (s-1) 1. 7 10 ^17 1. 2 10^14 Spectral dens(N/shot/1%bw) 1. 4 10^11 10^13 Tot. spect dens. (N/s/1%bw) 1. 4 10^18 1. 2 10^15 Coherence SASE Q=50 p. C, I=2 k. A, emit=0. 4 um DE/E=2 10^-4, a_w=0. 6, dt=10 fs Growth Spectrum 60 m Power 60 m

Simulation synthesis Photon/pulse/%bandwidth 20 m Und, lw=3 cm 60 m Und, lw=1 cm SASE Single spike Lost of efficiency due to short dimension

On the sample (90% attenuation along the beam line) Photon/pulse/%bandwidth 20 m Und, lw=3 cm 60 m Und, lw=1 cm SASE Single spike

Single spike regime Being based on the FEL SASE regime, the method does not produce coherent light, in a statistical sense. l(nm) Each field realization has different intensity, phase, pulse separation, … , due to jitters of the electron beam and SASE fluctuations. However, inside each single shot, intensity, phase, pulse separation and width are correlated or constant.

Do we need full coherence? Cascade 5 x 5 x 5 Three modulators, one radiator e-Energy=3. 8 Ge. V High Harmonics Generation in Gas: first attempt: 20 nano. J at 13. 12 nm, 60 p. C V Wavelength 13. 12 nm Wavelength 2. 625 nm Fifth harmonics L=15 m L= m Modulator 2 Modulator 1 Und. Period 3. 5 cm Und. Period 5 cm aw=2. 7 g=7436 aw=5. 293 g=7436 Wavelength 0. 525 nm Wavelength 0. 105 nm Fifth harmonics L=20 m Modulator 3 Und. Period 3. 5 cm aw=0. 8116 g=7436 Radiator Und. Period 1. cm aw=0. 4 g=7436 V

FEL based on bubble arc compressor or

Genesis simulations, high energy line Period aw e-Energy lamda 12 mm 0. 75 3. 2 Ge. V 3. 2 Ge. V 0. 75 0. 6 3. 8 Ge. V 3. 2 Ge. V 3. 8 Ge. V 10 mm charge rad-E (m. J) Phnumber spikes 2. 395 A 7. 3 p. C 8. 8 2. 395 A 36 p. C 46 7. 6 10^9 4 10^10 3 spikes SASE 1. 697 A 1. 736 A 1. 23 A 6. 8 10^9 3. 75 10^10 5. 10^9 2. 63 10^10 2. 4 10^9 1. 1 10^10 2 -3 spikes SASE SASE 7. 3 p. C 36 p. C 8. 44 6. 4 30. 4. 1 25.

Genesis simulations, high energy line

Genesis simulations, low energy line Period aw e-Energy lamda Phenergy charge rad-E (m. J) Phnumber per shot spikes 30 mm 2. 5 3. 2 Ge. V 2. 77 nm 451 e. V 36 p. C 153. 5 3. 35 D+12 3 -4 2. 5 3. 2. 5 Ge. V 3. 2 Ge. V 4. 35 nm 287 e. V 36 p. C 2. 77 nm 451 e. V 7. 3 p. C

Lamda=2. 77 nm SASE MS SS SS

High order harmonics generated in gases 25 n. J 12 nm

Where we are? FEL Mari. X High energy E-Energy 3. 2 -3. 8 Ge. V Und 1 cm-3 cm Ph-energy 1 A-4 nm Rep rate 1 MHz Tot. flux Flux per shot Coherence possible Mari. X Low energy Next talk FERMI SCSS PSI XFEL LCLSII