Experiments with magnetic bottles

Experiments with magnetic bottles

Melanie MuckeDepartment of Physics and Astronomy

Uppsala University, Sweden([email protected])

outline

part 1: magnetic bottle spectrometer• working principle• layout• features

part 2: synchrotron experiments• coincidences• ICD in water clusters

part 3: FEL experiments• covariance technique with neon• double core holes in hydrocarbons• pump-probe on thymine

part 1: magnetic bottle

Kruit and Read, J. Phys. E 16, 313 (1983): cylindrical poles of electromagnet around interaction region, drift tube with coild around for homogeneous guiding field,detector: MCP + phosphor screen

magnetic bottle – the beginning

e-

e-

strong magnetic field Bi weak magnetic field Bf

qi

vqf

v

z

magnetic bottle - principle

𝜔 𝑖=𝑒𝐵𝑖 /𝑚

𝑟 𝑖=𝑚𝑣 𝑖

𝑒𝐵𝑖

=𝑣 𝑠𝑖𝑛𝜃𝑖 /𝜔𝑖

angular frequency of motion

orbit (cyclotron radius)

angular momentum of circular motion

𝑙𝑖=𝑟 𝑖𝑚𝑣 𝑖=𝑚2𝑣2𝑠𝑖𝑛2𝜃 𝑖

𝑒 𝐵𝑖

Lorentz force

𝐿=𝑒𝑣×𝐵

Bi Bf

qi

vqf

v

magnetic bottle - principle

Bi Bf

qi

vqf

vadiabatic transition

sin𝜃 𝑓

sin 𝜃𝑖

=(𝐵 𝑓

𝐵𝑖

)12

𝑟 𝑓

𝑟 𝑖

=(𝐵𝑖

𝐵 𝑓

)12=𝑀

e.g. Bi = 1 T, Bf = 1 mT qf,max = 1.8°, M = 31.6

𝜔 𝑖=𝑒𝐵𝑖 /𝑚

𝑟 𝑖=𝑚𝑣 𝑖

𝑒𝐵𝑖

=𝑣 𝑠𝑖𝑛𝜃𝑖 /𝜔𝑖

angular frequency of motion

orbit (cyclotron radius)

angular momentum of circular motion

𝑙𝑖=𝑟 𝑖𝑚𝑣 𝑖=𝑚2𝑣2𝑠𝑖𝑛2𝜃 𝑖

𝑒 𝐵𝑖

Lorentz force

𝐿=𝑒𝑣×𝐵

permanent magnetinhomogeneous, strong field (0,4 T)

solenoidhomogeneous, weak field (0,5 mT)

e-

e-

magnetic bottle – as used

replace electromagnet by permanent magnet increase solid angle from 2p to 4p

• time-of-flight spectrometer – cover full kinetic energy range• high transmission over large kinetic energy range• high detection efficiency• capable of multi particle detection

ideally suited to investigate correlation between electrons

magnetic bottle – special features

time of flight spectra need pulsed light source need start signalneed to calibrate

part 2: experiments at BESSY

hn = IR … 10 kV

one electron bunchapprox. 20 mA

d = 76 m

BESSY IIrep. rate 1.25 MHz= 800.5 ns revolution time

synchrotron radiation

magnetic tipmesh

cluster beam flight tube (0.6 m) with homogeneousmagnetic field

detector flange with MCP stack &phosphor screen

joint project with AG Becker, FHI Berlin

experimental setup

B. Hartke, Angew. Chem. Int. Ed. 41, 1468 (2002).

... between molecule and liquid

water clusters

monomer

energies for water follow I. Müller and L. Cederbaum, JCP 125, 204305 (2006).

inner valence

outer valence

core level

continuum

binding energy (eV)

12,85- 19,11

33,37

Intermolecular Coulombic Decay

monomer dimer

12,85- 19,11

33,37

11,91- 19,74

32,59- 34,10inner valence

outer valence

core level

continuum


binding energy (eV)


monomer dimer

12,85- 19,11

33,37

11,91- 19,74

32,59- 34,10

double ionisation potential

„one-site“ 38,63 eV double ionisation potential

„two-site“ 2

7,97 eV

inner valence

outer valence

core level

continuum


binding energy (eV)


I. Müller and L. S. Cederbaum, JCP 125, 204305 (2006).

energy spectrum of the ICD-electron:

calculation for water tetramer

ICD in water clusters

S. Barth et al., JPC A 113, 13519 (2009).

cluster contribution

outer valenceinner valence

photoelectron spectrum of water

outer valenceinner valence

This state can decay via ICD.

+ ICD electrons

S. Barth et al., JPC A 113, 13519 (2009).

cluster contribution

photoelectron spectrum of water

investigate coincident electron pairs

electrons undistinguishable sort by flighttime

slow

fast

flight time electron 2


electron-electron coincidence measurement

neon tof-map





0

2

0

Ett

DE

time-to-energy conversion

tof map energy map

flight time e2

flig

ht ti

me

e1

kinetic energy e2

kin

etic

en

ergy

e1

hn = 45 eV

coincidence maps of water

expected range for water ICD

energy spectrum shows ICD

qualitative agreement with theoretical spectrum0

hn = 45 eV<N> = 40

ICD spectrum

energy spectrum of the primary electrons vs. kinetic energy

0

spectrum of the intermediate state

hn = 45 eV<N> = 40

coincident intensity vs. binding energy of the final state

DIP H2O monomer

0

spectrum of the final state

hn = 45 eV<N> = 40

• ICD feature shifts with photon energy

• energy of the ICD electron follows the theoretical predictions

M. Mucke et al., Nature Phys. 6, 143 (2010)

variation of the excitation energy

hn = 60 eV<N> = 200

monomercluster

no ICD in the monomer

M. Mucke et al., Nature Phys. 6, 143 (2010)

LCLS startinjector

Experiment and UV laser

~1500 m

part 3: experiments at the LCLS

large collaborations at LCLS

Uppsala UniversityM. MuckeV. ZhaunerchykM. KaminskaM.N. PiancastelliJ.H.D. Eland (also Oxford University)R. Feifel

Stockholm UniversityP. SalénP. v.d.MeulenP. LinussonR.D. ThomasM. Larsson

Imperial College LondonR.J. Squibb (now Uppsala University)M. SianoL.J. Frasinski

ELETTRA TriesteR. RichterK.C. Prince

SLACR. CoffeeM. GlowniaJ. CryanM. MesserschmidtS. SchorbC. BostedtJ. Bozek

Michigan UniversityT. OsipovL. FangB. MurphyN. Berrah

Hiroshima UniversityO. TakahashiS. Wada

Tohoku University, SendaiK. MotomuraS. MondalK. Ueda

MPI, HeidelbergL. FoucarJ. Ullrich

a new bottle...

experiments at the LCLS

AMO hutchHigh Field Physics chamberAug/Sep 2011

FEL beamspectrometer axis

sample beam

rep. rate 120 Hz

magnet

solenoid

FEL sample MCP

e-

e-

pulse parameters

trigger

from FEL

digitiser

online display

experimental set-up

covariance analysis

• difference in correlated and uncorrelated products of electron signals X and Y at two kinetic energies:

C(X,Y) = <XY> - <X><Y>

• jitter corretion (photon energy fluctuation)• partial covariance corrects for intensity fluctuations

of FEL: Cp(X,Y;I) = C(X,Y) - C(X,I)C(I,Y)/C(I,I)

• conditional covariance: groupwise analysis of data from shots of similar intensity

L.F. Frasinski et al., J. El. Spec. Rel. Phenom. 79, 367 (1996).

V. Zhaunerchuk et al., Phys. Rev. A 89, 053418 (2014).

L.F. Frasinski et al., Science 246, 1029 (1989).

Double Core Holes

at the same atomss DCH

at different atomsts DCH

creation of two core holes in a molecule by photon impact

high sensitivity to chemical environment

increased orbital relaxation effect

from L.S. Cederbaum et al., Chem. Phys. 85, 6513 (1986).

recent studies on DCHs

J.H.D. Eland et al., Phys. Rev. Lett. 105, 213005 (2010),P. Lablanquie et al., Phys. Rev. Lett. 106, 063003 (2011),P. Linusson et al., Phys. Rev. A 83, 022506 (2011),P. Lablanquie et al., Phys. Rev. Lett. 107, 193004 (2011),M. Nakano et al., Phys. Rev. Lett. 110, 163001 (2013),L. Hedin et al., J. Chem. Phys., submitted (2013).

synchrotron radiation + multi-particle coincidence

CH4

NH3

C 1s-2

N 1s-2

FEL + single-electron detection

L. Fang et al., Phys. Rev. Lett. 105, 083005 (2010),J. Cryan et al., Phys. Rev. Lett 105, 083004 (2010),N. Berrah et al., PNAS 108, 16912 (2011),P. Salén et al., Phys. Rev. Lett. 108, 153003 (2012),M. Larsson et al., J. Phys. B 46, 164034 (2013).

study of DCHs at FELs

use efficient electron spectrometer, employ covariance technique make up for low repetition rate of FEL pulses by • allowing for multiple ionisation events per light pulse • using a spectrometer of high detection efficiency • being able to handle multiple electrons per ionisation

event

study of DCHs at FELs

”core hole clock”: FEL pulse length vs. core hole lifetime get information on ionisation dynamics

use efficient electron spectrometer, employ covariance technique make up for low repetition rate of FEL pulses by • allowing for multiple ionisation events per light pulse • using a spectrometer of high detection efficiency • being able to handle multiple electrons per ionisation

event

neon: ionisation processes

photon energy 1062 eV

neon: covariance map core-region

FEL parameters40 pC charge mode0.35 mJ pulse energy≤ 10 fs pulse length1062 eV photon energy

neon: covariance map correctiondi

scim

inat

ed d

ata

jitter

cor

rect

ed

raw

dat

a

V. Z

haun

erch

yk, M

. Muc

ke,…

, and

R. F

eife

l, J.

Phys

. B 4

6, 1

6403

4 (2

013)

.

Four

ier d

econ

volu

tion

neon: coincidence vs. covariance

coincidence

V. Zhaunerchyk, M. Mucke, et al., J. Phys. B 46, 164034 (2013).

covariance


1

3

24

6au

toco

rrela

tion li

ne

5


1 PAP2 PP or PAPAP3 PAPVP, PPVAP or PAPsat

4 PAPAP5 DKV

6 DKVAP

neon: covariance maps

1

3

24

6au

toco

rrelat

ion lin

e

5

7

8

7 PVP8 PAPVP or PPVAP

L.J. Frasinski et al., Phys. Rev. Lett. 111, 073002 (2013), V. Zhaunerchyk et al., J. Phys. B 46, 164034 (2013).

first time distinguish PPV from PVP

1

3

24

6au

toco

rrela

tion li

ne

5

1 PAP2 PP or PAPAP3 PAPVP, PPVAP or PAPsat

4 PAPAP5 DKV

6 DKVAP

core-core region core-valence region

Double Core Holes in hydrocarbons

These slides have been deleted since the results are not yet published.If you want information on the outcomes of our investigation of double core hole states in hydrocarbons (C2H2 and C2H6) at the LCLS, please contact me ([email protected]).

summary on Double Core Holes

• 2dim covariance well suited for analysis of data from low repetition-rate light sources (handling of multiple ionisation events per light shot possible)

• identification of new few-photon processes by electron kinetic energies and comparison of intensity dependency of electron-pair features

• clear signatures for DCHs

Dt

ultrafast processes in thymine

... investigated by pump-probe spectroscopy

UV pump + XFEL probemagnetic bottleAuger difference spectra

Nora Berrah, WMUChristoph Bostedt, LCLS SLACJohn Bozek, LCLS SLACPhil Bucksbaum, PULSE SLACRyan Coffee, LCLSJames Cryan, PULSE SLAC Li Fang, WMUJoe Farrell, PULSE SLACRaimund Feifel, Uppsala UniversityKelly Gaffney, PULSE SLACMike Glownia, PULSE SLACMarkus Guehr, PULSE SLAC, SpokespersonTodd Martinez, PULSE SLAC,Brian McFarland, PULSE SLAC

Shungo Miyabe, PULSE SLACMelanie Mucke, Uppsala UniversityBrendan Murphy, WMU Adi Natan, PULSE SLACTimur Osipov, WMUVladimir Petrovic, PULSE SLACSebastian Schorb, LCLS SLAC Thomas Schultz, MBI, BerlinLimor Spector, PULSE SLACFrancesco Tarantelli, Univ. PerugiaIan Tenney, PULSE SLAC Song Wang, PULSE SLACBill White, LCLS SLACJames White, PULSE SLAC

Early Career GrantReference: McFarland et al. Nature Comm. 5, 4235 (2014)

thymine collaboration

pp*np*

Reaction coordinate

UV

pum

p

Groundstate

Pote

ntial

ene

rgy

np*

n

p

*pGS->pp*

4.5

eV Barrier?

Asturiol et al., J. Phys. Chem. A,113, 10211 (2009)Hudock et al., J. Phys. Chem. A,111, 85 (2007)

competing processes

pp*

np*

Reaction coordinate

Pote

ntial

ene

rgy

CICI

Neutralstates

UV

pum

p

Core ionizedstates

Dicationicstates

SXR

prob

e

Auge

r dec

ayE ki

n

Barrier?

Groundstate

GS

n

p

*pIP

Oxygen 1s

GS->pp*

UV

pum

pX-ray probe Auger decayUV pump

SXR

prob

e

Delay

Electr. Relax.

E kin

np*

Electr. R

elax.

O

O

pump-probe scheme

UV Pump Off UV Pump On

p* Auger Electrons

Difference signal: UV On-UV Off

Auger difference spectra

UV pump: 266 nmXFEL probe: 570 eVretardation 470 V

kinetic energy [eV]

Auger difference spectra

UV Pump Off UV Pump On

p* Auger Electrons

Difference signal: UV On-UV Off

III

III

kinetic energy [eV]

dela

y [p

s]

min

III

dela

y [p

s]de

lay

[ps]

McFarland et al, Nature Comm. 5, 4235 (2014)

IIII II

blue-shift of Auger lines

III

III

kinetic energy [eV]

dela

y [p

s]

min

III

dela

y [p

s]de

lay

[ps]

pp*np*

Reaction coordinate

UV

pum

p

Groundstate

Pote

ntial

ene

rgy


IIII II

min

blue-shift of Auger lines

54

III

III

kinetic energy [eV]

dela

y [p

s]

III

dela

y [p

s]de

lay

[ps]

pp*np*

Reaction coordinate

UV

pum

p

Groundstate

Pote

ntial

ene

rgy

min


IIII II

no barrier observed

the end

magnetic bottle spectrometer –versatile tool for detection of electrons,especially suitable for correlation studies

Experiments with magnetic bottles

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Transcript of Experiments with magnetic bottles