Option for Larger Bandwidth above 5 keV for crystallography: TN-15-13 - - PowerPoint PPT Presentation

▶
option for larger bandwidth above 5 kev for
SMART_READER_LITE
LIVE PREVIEW

Option for Larger Bandwidth above 5 keV for crystallography: TN-15-13 - - PowerPoint PPT Presentation

Dec 13, 2023 356 likes •496 views

Option for Larger Bandwidth above 5 keV for crystallography: TN-15-13 LCLS2 Wednesday seminar J. Zemella / Z. Huang LCLS Menlo Park DESY Hamburg 05-27-2015 Outline Parameters we are/I am aiming at Corrugated structure at LCLS1

slide-1
SLIDE 1

Option for Larger Bandwidth above 5 keV for crystallography: TN-15-13

LCLS2 Wednesday seminar

  • J. Zemella / Z. Huang

LCLS Menlo Park DESY Hamburg

05-27-2015

slide-2
SLIDE 2

Outline

  • Parameters we are/I am aiming at
  • Corrugated structure at LCLS1
  • Elegant simulations
  • Genesis simulations
  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 2 / 12

slide-3
SLIDE 3

Parameters ask for:

Post Workshop (3) LCLS-II Objective Parameters & Future Operating Modes

 Larger BW ~2%-4% BW (above 5 keV) - crystallography  BW & wavelength control 2.1-5 keV (<400 meV BW, ~40 fs) crystallography  Polarization HXU - vertical polarization (capacity, beam sharing)  Harmonics (HXU) performance & isolation from fundamental  Pulse pairs at variable spacing (0-1 ns, 5 ns-msec)

rough priority order subject of ongoing discussions & iteration with LCLS-II project

LCLS-II 2-pulse XPCS:

  • >1 ms ➜ 5 ns (RF buckets)
  • nsec, psec ➜ 10 fs (delay line)

t1 t2 t3 t4 t5 t6

1 ms

partiality problem

report on progress to covering the parameters copper linac is used to generate 5 keV photons

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 3 / 12

slide-4
SLIDE 4

Corrugated structure at LCLS1

two cases assumed:

1 base line corrugated structure 2x 2 m 2 base line corrugated structure; scaled

wake fields by factor of 2 (2x 4 m)

Parameter (unit) Value half gap a (mm) 0.5 (lower limit) periode p (mm) 0.5 depth h (mm) 0.5

  • pening g (mm)

0.25 width w (mm) 12 total length (m) 4

  • Z. Zhang et al., PRSTAB 18, 010702 (2015)

wake fields for 1 m long corrugated structure

single mode approx.

  • 80
  • 60
  • 40
  • 20

20 40 60 1 2 3 4 5 amplitude (kV/nC/mm) s (mm)

  • long. wake
  • 30
  • 20
  • 10

10 20 30 40 50 60 1 2 3 4 5 amplitude (kV/nC/mm**2) s (mm) dipole wake quadrupole wake

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 4 / 12

slide-5
SLIDE 5

Results of Elegant calculation.

initial upstream 4 m structure 8 m structure beam OTR2 ’full’ collimated ’full’ collimated ’full’ collimated beam energy (GeV) 0.135 11.86 11.87 11.86 11.87 11.86 11.87 charge (pC) 250 250 170 250 170 250 170

  • proj. emittance in x (μm)

0.68 1.27 0.97 1.28 0.95 1.62 0.95

  • proj. emittance in y (μm)

0.69 0.69 0.57 1.09 0.57 2.36 0.58 peak current (kA) 0.035 4.0 4.1 3.9 4.5 3.9 4.5 rms energy spread 0.077 0.24 0.16 0.40 0.27 0.56 0.38 rms bunch length (fs) 2310 41.6 15.8 41.6 15.7 41.6 15.7

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 5 / 12

slide-6
SLIDE 6

Some plots for electron bunch upstream of corrugated structure

250 pC charge 170 pC charge, collimated

a

  • 0.5
  • 0.2

0.0 0.2 0.5 relative energy deviation (%)

b

0.0 0.6 1.2 1.8 2.4 3.0 3.6

  • 100
  • 50

50 100 current (kA) time (fs)

c

  • 100
  • 50

50 100 0.0 0.2 0.4 0.6 0.8 1.0 1.2

  • norm. emittance (micron)

time (fs)

d

horizontal norm. emittance vertical norm. emittance

a

  • 0.3
  • 0.2
  • 0.1

0.0 0.1 0.2 0.3 relative energy deviation (%)

b

0.0 0.7 1.4 2.1 2.8 3.5 4.2

  • 45
  • 30
  • 15

15 30 45 current (kA) time (fs)

c

  • 45
  • 30
  • 15

15 30 45 0.0 0.2 0.4 0.6 0.8 1.0 1.2

  • norm. emittance (micron)

time (fs)

d

horizontal norm. emittance vertical norm. emittance

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 6 / 12

slide-7
SLIDE 7

Some plots for electron bunch downstream of 4 m long corrugated structure

250 pC charge 170 pC charge, collimated

a

  • 1.0
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.0 0.2 0.4 relative energy deviation (%)

b

0.0 0.6 1.2 1.8 2.4 3.0 3.6

  • 100
  • 50

50 100 current (kA) time (fs)

c

  • 100
  • 50

50 100 0.0 0.2 0.4 0.6 0.8 1.0 1.2

  • norm. emittance (micron)

time (fs)

d

horizontal norm. emittance vertical norm. emittance

a

  • 0.6
  • 0.4
  • 0.2

0.0 0.2 relative energy deviation (%)

b

0.0 0.7 1.4 2.1 2.8 3.5 4.2

  • 45
  • 30
  • 15

15 30 45 current (kA) time (fs)

c

  • 45
  • 30
  • 15

15 30 45 0.0 0.2 0.4 0.6 0.8 1.0 1.2

  • norm. emittance (micron)

time (fs)

d

horizontal norm. emittance vertical norm. emittance

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 7 / 12

slide-8
SLIDE 8

Some plots for electron bunch downstream of 8 m corrugated structure

250 pC charge 170 pC charge, collimated

a

  • 1.5
  • 1.2
  • 1.0
  • 0.8
  • 0.5
  • 0.2

0.0 0.2 0.5 relative energy deviation (%)

b

0.0 0.6 1.2 1.8 2.4 3.0 3.6

  • 100
  • 50

50 100 current (kA) time (fs)

c

  • 100
  • 50

50 100 0.0 0.2 0.4 0.6 0.8 1.0 1.2

  • norm. emittance (micron)

time (fs)

d

horizontal norm. emittance vertical norm. emittance

a

  • 1.0
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.0 0.2 relative energy deviation (%)

b

0.0 0.7 1.4 2.1 2.8 3.5 4.2

  • 45
  • 30
  • 15

15 30 45 current (kA) time (fs)

c

  • 45
  • 30
  • 15

15 30 45 0.0 0.2 0.4 0.6 0.8 1.0 1.2

  • norm. emittance (micron)

time (fs)

d

horizontal norm. emittance vertical norm. emittance

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 8 / 12

slide-9
SLIDE 9

Some plots of SASE FEL performance of a chirped bunch using 4 m corrugated structure

SASE pulse at 6.2 keV at 132 m with 250 pC bunch

0.02 0.04 0.06 0.08 0.1 0.12 0.14 25 50 75 100 125

energy (mJ) z (m)

1 2 3 4 5 6 7 8 10 20 30 40 50 60

power (GW) s (micron)

single shot mean over 10 shots 1 2 3 4 5 0.198 0.2 0.202

power (a.u.) wavelength (nm)

single shot mean over 10 shots

1.71%

SASE pulse at 6.2 keV at end of undulator with 170 pC collimated bunch

0.05 0.1 0.15 0.2 0.25 25 50 75 100 125

energy (mJ) z (m)

5 10 15 20 25 30 5 10 15 20 25 30

power (GW) s (micron)

single shot mean over 10 shots 0.5 1 1.5 2 0.198 0.2

power (a.u.) wavelength (nm)

single shot mean over 10 shots

1.25%

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 9 / 12

slide-10
SLIDE 10

Some plots of SASE FEL performance of a chirped bunch using 8 m corrugated structure

SASE pulse at 6.2 keV at 132 m with 250 pC bunch

0.01 0.02 0.03 0.04 0.05 0.06 0.07 25 50 75 100 125

energy (mJ) z (m)

1 2 3 4 5 6 7 8 10 20 30 40 50 60

power (GW) s (micron)

single shot mean over 10 shots 0.5 1 1.5 2 0.198 0.2 0.202

power (a.u.) wavelength (nm)

single shot mean over 10 shots

1.76%

SASE pulse at 6.2 keV at end of undulator with 170 pC collimated bunch

0.05 0.1 0.15 0.2 0.25 25 50 75 100 125

energy (mJ) z (m)

5 10 15 20 25 30 35 5 10 15 20 25 30

power (GW) s (micron)

single shot mean over 10 shots 0.5 1 1.5 2 2.5 0.198 0.2

power (a.u.) wavelength (nm)

single shot mean over 10 shots

1.76%

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 10 / 12

slide-11
SLIDE 11

Some plots of SASE FEL performance of a chirped bunch with 0.5 % linear taper (75-132 m)

SASE pulse at 6.2 keV at end of undulator with 250 pC bunch for 4 m long structure

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 25 50 75 100 125

energy (mJ) z (m)

20 40 60 80 100 120 0 5 10 15 20 25 30 35 40 45 50 55 60

power (GW) s (micron)

single shot 0.5 1 1.5 2 0.197 0.198 0.199 0.2 0.201

power (a.u.) wavelength (nm)

single shot

1.25%

SASE pulse at 6.2 keV at end of undulator with 170 pC collimated bunch for 4 m long structure

0.2 0.4 0.6 0.8 1 1.2 1.4 25 50 75 100 125

energy (mJ) z (m)

20 40 60 80 100 120 140 160 180 5 10 15 20 25 30

power (GW) s (micron)

single shot 0.5 1 1.5 2 0.197 0.198 0.199 0.2 0.201

power (a.u.) wavelength (nm)

single shot

1.3%

SASE pulse at 6.2 keV at end of undulator with 170 pC collimated bunch for 8 m long structure

0.2 0.4 0.6 0.8 1 1.2 25 50 75 100 125

energy (mJ) z (m)

20 40 60 80 100 120 140 5 10 15 20 25 30

power (GW) s (micron)

single shot 0.5 1 1.5 2 0.197 0.198 0.199 0.2 0.201

power (a.u.) wavelength (nm)

single shot

1.25%

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 11 / 12

slide-12
SLIDE 12

Summery/Conclusion

  • 4 m long corrugated structure is able to generate SASE pulse up to 1.7 % relative bandwidth.
  • 8 m long corrugated structure is able to generate SASE pulse up to 1.8 % relative bandwidth.
  • Increasing the length of structure does not improve bandwidth for uncollimated bunch

(strong trans. wake fields). Increase of 0.5 % relative bandwidth for collimated case.

  • Increasing the SASE pulse energy using a undulator taper reduces the bandwidth to 1.3 %

for both assumed lengths of corrugated structure.

  • Inreasing length of corrugated structure does not improve bandwidth.
  • Reverse taper of undulator increase bandwidth but also reduces SASE pulse energy.
  • Collimated bunches seem to be better.
  • Larger charge and collimation (350 pC → 250 pC) may increase the chirp of bunch and

therefore bandwidth of SASE pulse.

  • J. Zemella / Z. Huang

(DESY) LCLS2 seminar. 05-27-2015 12 / 12