Subterahertz Radiation from Corrugated Pipe - DESYpitz.desy.de/sites2009/site_pitz/content/e147005/e204860/e206837/... · Subterahertz Radiation from Corrugated Pipe Igor Zagorodnov

Self-Consistent Simulation of Longitudinal Dynamics

Subterahertz Radiation from Corrugated Pipe

Igor Zagorodnov

Mini-workshop on THz option at PITZ (piTHz)

Zeuthen22. September 2015

Igor Zagorodnov | Mini-workshop on THz option at PITZ (piTHz) | 22. September 2015 | Seite 2

Problem fomulation . Relativistic bunch .


Problem fomulation . Low energy


Problem fomulation . Geometry

Pipe radius �, mm 2

Pipe length �, m 0.5-2

Corrugation depth �, mm 0.05

Corrugation period �, mm 0.04

Corrugation gap �, mm 0.02

Gausiian bunch rms �, mm 0.1-0.3(*8)


Code modification

Wakefield code ECHO(with resistivity)

Particle-in-Cell code ECHO-PIC(only longitudinal dynamics)


Short bunch . High charge . High Energy

Pipe length �, m 0.5

Bunch enegry ��, MeV 14000

Gausian bunch rms �, mm 0.1

Charge , nC 1



0 1 2 3 4 5-5

0

5x 10

6

-0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.50

500

1000

1500

1 nC

σ 0.1mm

�� 14 GeV2∆�[eV/m]

�[mm]

�[mm]

�[A]



0 1 2 3 4 5-4

-3

-2

-1

0

1

2

3

4

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.50

0.2

0.4

0.6

0.8

1

1.2

1.4

∆�[MeV]

σ 0.1mm�� 14GeV

�[mm] �[m]

∆�[mJ]

1 nC


Short bunch . High charge . Low Energy


Bunch enegry ��, MeV 5-20


Charge , nC 1



0 0.1 0.2 0.3 0.4 0.5-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 0.1 0.2 0.3 0.4 0.5-0.2

0

0.2

0.4

0.6

0.8

1

1.2

0 0.1 0.2 0.3 0.4 0.5-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1 nC σ 0.1mm

�� 10MeV�� 20MeV �� 5MeV

� [m]

∆�[mJ]

�[m] �[m]



0 0.2 0.4 0.6 0.8 1 1.2 1.4-2

0

2

4x 10

6

0 0.2 0.4 0.6 0.8 1 1.2 1.40

500

1000

1500

2 2.5 3 3.5 4-2

-1

0

1x 10

6

1.5 2 2.5 3 3.5 40

200

400

1 nC σ 0.1 mm

�� 10 MeV �� 5 MeV

�[mm] �[mm]

�[A]

∆�[eV]

�� 1200A



1 nC σ 0.1mm

�� 10 MeV �� 5MeV

�[mm]

�[mm]

Longitudinal electric field component ��

� � 0.3 THz

�[mm]

�[mm]


Short bunch . Low charge . Low Energy


Bunch enegry ��, MeV 5-20


Charge , nC 0.04



0 0.1 0.2 0.3 0.4 0.5

0

0.5

1

1.5

2

2.5x 10

-3

0 0.1 0.2 0.3 0.4 0.50

0.5

1

1.5

2

2.5x 10

-3

0 0.1 0.2 0.3 0.4 0.50

0.5

1

1.5

2

2.5x 10

-3�� 10 MeV�� 20 MeV �� 5MeV

�[m]

∆�[mJ]

� [m] � [m]

∆�[mJ] ∆�[mJ]2.2 µJ

40 pC σ 0.1mm �� 48A



0 0.2 0.4 0.6 0.8 1 1.2 1.4-1

0

1

2x 10

5

0 0.2 0.4 0.6 0.8 1 1.2 1.40

500

1000

1500

2 2.5 3 3.5-1

0

1

2x 10

5

2 2.5 3 3.50

500

1000

1500

40 pC σ 0.1mm

�� 10 MeV �� 5 MeV

� [mm] � [mm]

25*�[A]

∆� [eV]

�� 48A

48A



�� 10 MeV �� 5 MeV

�[mm]

�[mm]


� � 0.3 THz

�[mm]


Middle bunch . Middle charge . Low Energy




Charge , nC 0.12



0 0.1 0.2 0.3 0.4 0.5

0

2

4

6

8

10x 10

-4

-1 0 1 2 3-1

0

1x 10

5

-1 0 1 2 30

200

400

600

120 pC σ 0.3mm �� 48A�� 10 MeV

�[m]

∆�[mJ]

�[mm]

��

��[A]

∆�[eV]

48A

0.55µJ



� � 0.3THz

� [mm]

� [mm]



Premodulated bunch (from M. Krasilnikov)

� Edges of the flat-top pulses are slightly shorter than FWHM of the Gaussian pulse (measured without shaper)

� “Smoothening” of the Modulations in the flat-top region of the pulse

Lyot: 6 mm YLF Lyot: 4 mm YVO 4no Lyot filter

FWHM = 2.5 ps

FWHM = 4 ps

FWHM = 7 ps

FWHM ~ 16 ps

edges ~ 2ps edges ~ 3ps

2 4 ps

2 5 ps2 5 ps 2 5 ps 2 5 ps

2 5 ps2 5 ps 2 5 ps 2 5 ps

with shaper (13 crystals)

withoutshaper

Lyot: 16 mm YLF

~ 2 3 ps

edges ~ 6 ps

~ 19 ps

~ 14 ps

I. Will, G. Klemz „Increasing the flexibility in pulse shape of a Yb:YAGphotocathode laser” 20.06.2009


Premodulated bunch . 6 microbunches



Gausian bunch rms �, mm 0.3*6

Charge , nC 0.12*6

-4 -2 0 2 40

10

20

30

40

50

�[mm]

�[A]



0 0.2 0.4 0.6 0.8 10

0.005

0.01

0.015

0.02

0.025

0.03

-5 0 5 10-5

0

5x 10

5

-5 0 5 100

100

200

300

� [m]

∆�[mJ]

6 ∗ 120 pC

σ 0.3mm

�� 48 A�� 5 MeV

�[mm]

� [A]

∆�[eV]

Microbunching spacing ∆� 0.93 mm



� � 0.35 THz

�[mm]

�[mm]


�� 5MeV



0 0.5 1 1.5 20

0.05

0.1

0.15

�� 20MeV� � 0.3THz

�� 5 MeV� � 0.35 THz

� [m]

∆� [mJ]

Microbunching spacing ∆� 0.93mm

140µJ



Pipe length �, m 1.5-2



Charge , nC 0.12*8

-5 0 50

10

20

30

40

50

�[mm]

�[A]



Microbunching spacing ∆� 0.93 mm

�� 20 MeV

�[mm]

�[A]

∆�[eV]

�� 5MeV

�[mm]

�[A]

∆�[eV]


0 0.5 1 1.5 2

0

0.05

0.1

0.15



145 µJ

�� 5MeV� � 0.35THz

� [m]

∆�[mJ]



Pipe length �, m 2



Charge , nC 0.12*8




0 0.5 1 1.5 20

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

410µJ

�� 20MeV� � 0.3 THz

�� 8MeV� � 0.33 THz

�[m]

∆�[mJ]

125µJ



� � 0.33 THz

�[mm]

�[mm]


�� 8 MeV


Summary

Charge,[pC]

Beamenergy,[MeV]

RMSlength,[mm]

Numberof

bunches

Pipe Length

[m]

Field energy,

[uJ]

Frequ-ency,[THz]

1000 14000 0.1 1 0.5 1400 0.3

1000 20 0.1 1 0.5 1300 0.3

40 10 0.1 1 0.5 2 0.3

120 10 0.3 1 0.5 0.55 0.3

120*8 20 0.3 8 1.5 85 0.3

120*8 5 0.3 8 1.5 140 0.35

120*8 8 0.3 8 2 410 0.33


Summary

To consider:- transverse dynamics,- tapering, resonance condition,- resistivity (already implemented in

code),- rectangular pipe (wakefield code

available),- start from shot noise, - Start with short driving bunch,- optimal prebunching, optimal energy.

Documents

Subterahertz Radiation from Corrugated Pipe - DESYpitz.desy.de/sites2009/site_pitz/content/e147005/e204860/e206837/... · Subterahertz Radiation from Corrugated Pipe Igor Zagorodnov