BEAM DIAGNOSTICS AND RADIATION DETECTION SYSTEM

BEAM DIAGNOSTICS AND

RADIATION DETECTION

SYSTEM

Alexander S. Aryshev, Ph.D.

Assistant Professor

KEK: High Energy Accelerator Research Organization,

1-1 Oho, Tsukuba 305-0801, Ibaraki-ken, Japan.

TEL: +81-298-64-5715, FAX: +81-298-64-0321.

e-mail: [email protected]

3rd international school on Beam Dynamics and Accelerator technology, 25 Feb. – 3 Mar. 2021

Outline • Introduction

• Transverse Parameters Measurements – Monitor beam position (BPMs)

– Monitor beam charge (CTs)

– Wire scanners

– Laser-wires

– Monitor beam profile (Screens)

– EM radiation review

– OTR/ODR

• Longitudinal Parameters Measurements – RF deflector

– Coherent radiation theory

– CTR/CSPR

– GHz/THz detectors

– GHz/THz interferometers

– Bunch shape reconstruction

• Additional references

• Summary

02 March 2021 3rd international school on Beam Dynamics

and Accelerator technology

General review • Accelerator performance depends critically on the ability to

carefully measure and control the properties of the accelerated

particle beams.

• This reflects in part the increasingly difficult demands for high

beam currents, smaller beam emittances, and the tighter

tolerances placed on these parameters (e.g. position stability) in

modern accelerators.

• A good understanding of diagnostics (in present and future

accelerators) is therefore essential for achieving the required

performance.

• A beam diagnostic consists of the measurement device

associated electronics and processing hardware.

• “Beam Diagnostics and Applications”, A. Hofmann (BIW 98)



Why it is a big deal?

• Good knowledge of accelerators, general physics and technologies needed.

• Quite different technologies are used, based on various physics processes.

• Each task and each technology calls for an expert.

• Applicability (in term of a reliable results) of various diagnostics types greatly depends on machine type, particles types and beam parameters.

• Well established techniques are not always applied.

• Quick, remotely controlled, on-line, non-destructive, multifunction and possibly single-shot measurements needed.

• Accelerator development goes parallel to diagnostics development.



Typical linear accelerator beamline





Diagnostic devices and beam properties

measured



Effect on beam: • “N” – none • “-” – negligible • “+” – perturbing • “D” – destructive

• “” – primary purpose

• “” – indirect use

Diagnostic of High Brightness Electron

Beams HB E-beam diagnostic

General: •bunch charge

FC, ICT, Toroids

•transverse position

BPM: button, stripline,

cavity

•arrival time (phase)

BAM, RF pickups

Projected Slice

Longitudinal

(temporal)

Transverse

Current

profile

Energy

distribution

Long.

phase

space

Slice

energy

spread

Slice

emittance

Proj.emittance,

transv. phase

space

Transverse

profile

ynxn

n

IB

Challenges • high charge / charge

density

• small beam dimensions

(100…50um nm!)

• high repetition rate

• all the intercepting devices

are damaged by measured

beams

• beam halo measurements



Transverse Parameters Measurements

• OTR monitors (~um Al foil)

– High energy (>tens of MeV)

– No saturation

– Resolution limit closed to optical diffraction limit (~10um)

– COTR effects (especially for compressed bunches)

• Scintillator screens (e.g. YAG:CE, 100um)

– High photon yield

– Resolution grain dimensions (~50um?) (powder / thin crystal)

– Saturation (0.04pC/um^2?)

• Wire Scanner (good agreement with YAG measurements!)

– Almost non-invasive

– Higher beam power

– Multi-shot measurements

– 1D

– Rather complicated setup, long measurement time

• Diamond screen long pulse train

• “Indirect” (SR – Optical Synchrotron Interferometry, Scattering, ODR, etc)

Usually the largest error in transverse parameters measurements is coming from transverse

profile and rms size determination.

Readout:

•Zoom optics

•CCD camera

• 12bit

• l~ 1um..400nm

• controllable iris

•Insertable filters



Transverse Phase Space (Emittance)

Measurements

Space charge

dominated

Emittance dominated

Slit mask techniques:

• based on

conversion of a

space charge

dominated beam into

emittance dominated

beamlets

•Multi screen:

•Based on linear beam matrix

approach

•3 beam size measurements (at

3 positions) are needed for the

known elements of the transport

matrix (phase advance)

•Quad(s) scan

•Beam size measurements as a

function of varied transport

matrix

•Tomography

•Related to Radon theorem: N-

dim object reconstruction from M

projections in (N-1) dim space

• Systematic error from quad

strength determination

(e.g hysteresis)

• Thin lens model is not

adequate

• Large energy spread

chromatic effects

• Phase space distribution

assumed to be homogeneous



Slit technique - general

-2 -1 0 1 2-30

-20

-10

0

10

20

30

x

px

Transverse phase space reconstruction

L

Space charge

dominated beam

Emittance

dominated

beamlets

222 xxxxnx

•Slit mask:

• Opening: small enough

• Thickness: thick enough to scatter beam, but

alignment / angle acceptance

•Distance L:

•Long enough divergence resolution

•Not too long signal-to-noise

Multi slit mask = single shot measurement, but:

•Overlapping of beamlets when optimized for high resolution

•Low sampling of the phase space



Transverse projected emittance measurements at PITZ

EMSY1 (z = 5.74 m) Observation

screen

2.64 m

Single slit scan technique

> Emittance Measurement SYstem (EMSY) consists of horizontal / vertical actuators with

YAG / OTR screens

10 / 50 m slits

> Beam size is measured @ slit position using screen

> Beam local divergence is estimated from beamlet sizes @ observation screen

> 12-bit camera, quality criteria: max bit>3000 (from 4095=2^12-1); adjustment = gain X NoP

> Image filtering (3sigma, bkg, x-ray, MOI) 2D scaled normalized RMS emittance

222

2xxxx

x

xn

x - RMS beam size measured with YAG screen at

slit location

SQRT(<x2>) - RMS beam size at slit location

estimated from slit positions and beamlet intensities

“100% RMS emittance”

scale factor ( >1 ) introduced to correct for low

intensity losses from beamlet measurements

pixel intensity

transverse phase space beam at EMSY screen



Beam Position Monitors (BPMs)

• Used in high intensity machines with short bunches and Synchrotron light sources.

• The BPM consists of four metal buttons on the inside of the accelerator structure, connected to wires that extend outside the structure and are grounded.

• The entire apparatus is electrically isolated from the accelerator structure itself.

• The information from the four buttons can be used to measure the number of electrons in the bunch and determine the position of the bunch.

• Buttons are used frequently in synchrotron light sources are a variant of the capacitive monitor.

• Picks up the wall currents at several positions

• Huge dynamic range but poor resolution ~10um (typ.)



Beam Position Monitors (BPMs)



Stripline BPM

• Stripline has 4 strips running along the axes of beam, parallel to the vacuum chamber wall.

• The length of the strip is usually longer than the characteristic bunch length and equal to quarter wavelength of fundamental RF.

• The electromagnetic field of the beam induces signal on the strip line.

• The amplitude of signal is a function of its solid angle subtended on the beam and distance of the conductor from the beam.

• Two ends of the stripline are taken out of the chamber. These are called upstream and downstream ports respectively with reference to the beam direction.

• Better resolution <10um



Much better for a short bunches

LUCX BPMs



Current transformers

• Simple design

• Of-the-shelf availability

• Fast response

• Femtosecond bunch

generates good signal



WIRE SCANNER

• Device with a thin fiber (tungsten or carbon) moving across the transverse section of the beam.

• Interception of the beam produces bremsstrahlung photons and secondary emission electrons. Either rays or secondary e- can be used for the information on beam profiles (Hor. & Ver.).

• The W.S. is attached to a precision stepped device moving with m steps.

• The rms resolution of a W.S. is d/4, where d, is the wire diameter.

• For example, a 5 m rms beam measurement would be widened by only 6% , with a 7 m diameter W.S.



Some details on Wire Scanners

• Usually, two wires (H&V) are

mounted on a fork which is

displaced at 45 degrees to the

horizontal plane.

• In some cases, the rays are

converted into pairs which create

Cherenkov Radiation in a

medium (ex. SLAC/FFTB).

• Minimum diameter size actually

realized is of 4 m, leading to a

minimum resolution of 1 m.



LASER WIRE MONITOR

• Principle : Compton scattering of the electron beam by a laser

light sent at right angle to the beam. The emitted (hard)

photons are measured in the forward direction.

• The laser beam waist is realized in the center of a Fabry-Perot

cavity (low power laser) or without the cavity (high laser energy

per pulse)

• The counting rates of scattered photons are measured as a

function of the laser-wire position

• The actual electron beam profile is obtained after

deconvolution with the known laser distribution



Laser Interferometer Technique

• This technique, used by T.Shintake at FFTB, uses

interferometry technique with a YAG-laser beam split into two

beams which collide, perpendicularly, with an electron beam.

The Compton back scattered , in the forward direction (e-) are

directed to a -detector (Conv. + gas Cerenkov). As the laser

light is producing a fringe pattern, the ’s present periodic

variations with llaser along laser axis, when scanning the beam.

Modulation depth=> size

• This technique allows high accuracy;

– a 60 nm spot (V) was measured at FFTB.

– a 40 nm (V) was measured at KEK ATF



Screen monitors

• Incoherent light monitors

– Luminescent screens

– Optical Transition Radiation (OTR) monitor

– Optical Diffraction Radiation (ODR) monitor

– Cherenkov radiation monitors

• Coherent light monitors

– Coherent Transition Radiation (CTR)

– Coherent Diffraction Radiation (CDR)

– Coherent Cherenkov Radiation (CChR)

– Coherent Resonant Diffraction Radiation (so-called Smith-Purcell radiation, CSPR)



KEK LUCX Screens



LUCX Screens



UV

e-beam

Luminescent screens

• When a beam passes through a luminescent screen, part of the deposited energy results in excited electrostatic states in the material from which a light emission at a defined wavelength will follow.

• The light emission originates in impurity inclusions, the so-called activators, in most of the used materials.

• They allow a direct observation of the beam position and shape on a TV monitor.

• They are necessarily single-pass monitors.

• Not very accurate



courtesy: Gérard Burtin (CERN).

Beam Profile Monitors (Screens)



courtesy: H. Koziol (CERN).

• Profile, roll • Position • Charge • Energy • Energy spread

For Bunch length or Bunch profile one have to take into account transverse beam size.

V.L. Ginzburg and I.M. Frank, Zh. Eksp. Teor. Fiz. 16 (1946) 15.

Types of radiation

Electromagnetic radiation generated by charged

particles can be divided into two categories:

– Bremsstrahlung (gas, plasma); radiation of hard

photons due to acceleration (synchrotron radiation,

undulator rad., channeling rad., etc.)

– Polarization radiation (radiation of soft photons;

acceleration is not required (Vavilov-Cherenkov

rad., Transition rad., etc.);)



Polarization Radiation (PR)

• Macroscopic treatment of PR began from works on

– Vavilov-Cherenkov radiation, VChR (Cherenkov, 1934; Tamm, Frank, 1937),

– Transition radiation, TR (Ginzburg, Frank, 1945),

– Difraction radiation, DR (Bobrinev, Braginsky, 1958; Dnestrovsky, Kostomarov, 1959),

– Smith-Purcell radiation, SPR (Smith, Purcell, 1953),

– and this is not the end of the list...



Transition Radiation

• Transition radiation is created

when a charged particle crosses the

interface between two media of

different optical properties.

• The radiation is emitted in two

directions:

• Forward: in direction of beam

propagation

• Backward: in direction of specular

reflection.

• Wide wavelength range OTR can be used for transverse beam profile measurements.

• Silicon screens + Ag or Al coating.

• Often beams are far from Gaussian especially in LINACs.

• Camera must be protected from radiation requiring a complex optical lines.

• Filters are needed to avoid saturating the camera.



Transition Radiation: possible measurements

• Bunch length: due to the rapid formation of the radiation (~10E-13 s), it is possible to measure very short bunches:

– With a Streak-Camera (SC): the limitation is brought by the SC resolution (~ps)

• With coherent TR using wavelengths comparable to the bunch size:

– resolution < ps

• Transverse phase space:

– transverse dimensions are measured with CCD cameras at the image plane of the lens

– angular distributions are measured with a CCD camera at the focal plane of the lens.

• Beam energy:

– determined by the angular position of the maxima (1/)

– … or just a transverse size in the dispersion section.



Backward TR (horizontal polarization)

3rd international school on Beam Dynamics


22 22

2 2 2 2 2

sin cos sincos

(1 sin cos sin ) cos cos

dW e

d d c

16

02 March 2021

Backward TR (vertical polarization)



22 22

2 2 2 2 2

cos sin sincos


dW e

d d c

16

02 March 2021

Backward TR



dW dW dW

d d d d d d

16

02 March 2021

1. D.V. Karlovets and A.P. Potylitsyn, JETP Lett. 2009, Volume 90, Number 5, Pages 326-331

2. D. V. Karlovets, JETP, 2011, Volume 113, Number 1, Pages 27-45

Transition Radiation: some activities at LAL-Orsay

• The more “recent” activities with OTR in LAL, concerned:

– a test on the OTR resolution on the 2 GeV Orsay e- linac

On figure H profile, =0.3 mm

– a series of measurements on the Tesla Test Facility (TTF) at DESY. In that case, beam emittance has been determined and observations on beam behavior inside the pulse, also.

-> PhD report of A.Variola

M. Castellano and V. A. Verzilov, PRST-AB 1, 062801 (1998)



Study of OTR resolution

• Theoretical & Experimental studies to determine resolution

• Theoretical: Rule&Fiorito, X.Artru et al, M.Castellano

PhD thesis (K.Honkavaara: Orsay)

{Figure from PhD report of KH}

• Experiments at LAL-Orsay (2 GeV), CEBAF (4 GeV) and CERN (22 GeV), showed an OTR resolution << l

• => practical resolution: FWHM

• of the diffraction function

• => OTR measurements of small beams at high energy: possible



Beam size effect on OTR

“Usual” OTR image

OTR vertical polarization

component,

for sigma < ~15* um



OTR image and Quadrupole scan.



100um

Pavel Karataev, Alexander Aryshev, Stewart Boogert, David Howell, Nobuhiro Terunuma, and Junji Urakawa Phys. Rev. Lett. 107, 174801 – Published 17 October 2011

FFTB Single Pulse Damage Coupon Test - front and back side - same scale

Front

Front

Front

Front

Back

Back

Back

Back

2 1010 8 x 6 m

2 1010 8 x 6 m

2 1010 9 x 8 m

2 1010 9 x 11 m

Four pairs of single pulse damage holes front and back



Diffraction Radiation

• Small recall:

As for Cherenkov Radiation and Transition Radiation, the

Diffraction Radiation was studied by Russian theoreticians

Papers from 1958 (Y.Dnestrovskii and D.Kostomarov), analysed

the radiation of a beam of particles passing through a circular

aperture. Later, in 1962, A.Kazantsev and G.Surdovich studied

the radiation of a particle beam, close to a metal screen. They

considered this radiation as resulting from the diffraction of the

electromagnetic field of the particle by the metal screen.



Diffraction Radiation: a simple approach

• We can consider the DR as

resulting from the diffraction of

the virtual photon flux by the

aperture (hole, slit, edge).

[Figure from Moran in NIMB]

• The source of DR is a “disk” of

diameter l/2. Consider a slit of

aperture a:

* l<<2a =>DR radiation ~0

* l>>2a =>DR similar to TR

* l ~ 2a =>DR intensity<TR,

but enough for measurement



Principle:

1. Electron bunch moves through a high precision co-planar slit in a conducting screen (Si + Al coating).

2. Electric field of the electron bunch polarizes atoms of the screen surface.

3. DR is emitted in two directions: – along the particle trajectory “Forward Diffraction

Radiation” (FDR)

– In the direction of specular reflection “Backward Diffraction Radiation” (BDR)

Diffraction Radiation

θ0

θy

e-

DR Angular distribution

Impact parameter:

ℎ ≤𝛾𝜆

2𝜋

Generally: DR intensity ⇧ as slit size ⇩

h



Diffraction Radiation: status

• Theoretical works made a while ago (Ter-Mikaelian,..)

– More recent calculations by Moran, Rule and Fiorito, Castellano, Potylitsin, Artru

• Measurements (few) are concerning :

– bunch length measurements (coherent DR; l~mm); Y.Shibata et al

– transverse beam characteristics (slit 1mm, l=1.6 m) at ELETTRA

(team M. Castellano) and DESY (A.Cianchi, M.Castellano, G.Kube et.al)

• At KEK ATF (P. Karataev, et.al.), with an inclined edge at some

tens of m of beam axis. Detection of optical l for 1.28 GeV

e- beam (angular distribution).

Note: as for TR, the DR resolution depends on the optical acceptance

Due to its non-invasive character, DR will have large developments



Pavel Karataev, Sakae Araki, Ryosuke Hamatsu, Hitoshi Hayano, Toshiya Muto, Gennady Naumenko, Alexander Potylitsyn, Nobuhiro Terunuma, and Junji Urakawa Phys. Rev. Lett. 93, 244802 – Published 8 December 2004

Vertical polarisation component of 3-dimensional (θx, θy, Intensity) DR angular distribution.

PVPC is obtained by integrating over θx to collect more photons.

Visibility (Imin/Imax) of the PVPC is sensitive to vertical beam size σy.



Source of background Contribution

SR from beamline optics High

Camera noise Low

Residual background

SR + DR interference

SR suppression

P. Karataev et al., Proc. of EPAC 2004, THPLT067

θ0

θy

e-

Use a mask upstream of target to suppress SR contribution.

E = 2.1 GeV λ = 400 nm a = 0.5 mm

Mask Target

OTR ODR

Diffraction Radiation measurements background



Summary: comparison of different methods

Methods Invasive ? Limit (m) Defined by Intense beam

OTR (rms) yes ~ 5 CCD pixel size

+optics

no

OTR (PSF) yes < 1 CCD sensitivity +

Optical background

no

ODR no ~ 9 CCD pixel size

+optics

yes

Wire scanner yes ~ 4 Wire diameter no

Laser wire

(cavity)

no < 1 Laser (l) +

Cavity mode

yes

Laser-wire

(high E)

no < 1 Laser (l) +

transverse beam

quality, FF lens

yes



Bunch length measurements

• Direct time-of-flight measurements – Streak camera (Profile reconstruction, Single Shot, Expensive, Space-

charge limited)

– Deflecting cavity (Same as above)

– Cavity-BPM (preliminary) (RMS relative length change, Calibration?)

• Electro-optical methods – Profile reconstruction, Single shot

– http://www-library.desy.de/preparch/desy/thesis/desy-thesis-11-017.pdf

• Methods based on coherent spectrum – Spectral measurements

• Longer wavelengths

• Lack of broadband detectors

• Care is needed (absolute calibrations, linearity, spectral response)

– Bunch profile reconstruction • Complicated mathematics

• Dependence on radiation generation mechanism



Longitudinal Parameters Measurements

Temporal beam profile (bunch length) r(t)

Time Domain Frequency Domain Optical and laser techniques

Radiator +

Streak-

camera

RF

deflector

Coherent radiations +

Interferometer

Cherenkov

Laser Wire

•Non intercepting and not disturbing

•Multi shot

•Complicated setup

•Interferometers (Michelson; Martin-Puplett)

•Spectrum acceptance is restricted can

impact the reconstructed beam profile

•Guess distribution is needed

Intercepting diagnostic

•Radiators

•OTR (Al foil)

•Cherenkov (aerogel)

•Streak camera

•T-resolution limited to 200...300 fs

•Rather expensive

•Light collection \transport

dispersion free beam line is

needed (reflective optic instead of

lens)

Transition = CTR

Synchrotron CSR

Smith-Parcell

Diffraction = CDR

Electro Optical Sampling = EOS

•Non intercepting and not disturbing

•Based on optical properties of a

non-linear crystal interacting with

Coulomb field of e-beam



Longitudinal Parameters Measurements: RF deflector

RF Deflector:

•Self calibration (cavity phasing)

•Single shot

•Intercepting diagnostic

•Resolution down to tens of fs (f, V, tr)

•small transverse beam size and large beta function

•uncorrelated transverse energy spread

•induced slice energy spread

•phase jitter of the beam w.r.t. RFD

Map time (longitudinal) axis onto transverse coordinate

OTR beam images in the LCLS injector at 135MeV

for a 800um long bunch with the deflecting cavity off

(left) and on at 1MV (right).

H. Loos, “Longitudinal diagnostics for short electron

beam bunches”, SLAC-PUB-14120

RFD off RFD on



Longitudinal phase space measurements Spectrometer dipole RFD (Energy scale from beam in spectrometer, time scale with

transverse deflector)

Fast single shot measurements

LCLS: 135 MeV SPARC: 145MeV

Imaging of longitudinal phase space with RF deflector

E

t



Screen monitors

• Incoherent light monitors

– Luminescent screens

– Optical Transition Radiation (OTR) monitor

– Optical Diffraction Radiation (ODR) monitor

– Cherenkov radiation monitors

• Coherent light monitors

– Coherent Transition Radiation (CTR)

– Coherent Diffraction Radiation (CDR)

– Coherent Cherenkov Radiation (CChR)

– Coherent Resonant Diffraction Radiation (so-called Smith-Purcell radiation, CSPR)



x

y

z

L

rx

e-

y

n

e1

b1

e2

o

Theory of Coherent radiation

l

,1 zFNNNd

dPP

Radiative power of CSR emitted by a bunch of electrons

])/(4exp[2exp2

exp2

1, 2

2

2

2

2l

l

l z

zz

z dzz

iz

F

L

dtc

Rti

n

nne

E 0 2

0

exp

124

Fourier transform of the electric field of a moving charge (so-called Lienard-Wiechert potentials for a moving charge)

yxyyxn coscos,sin,cossin

rr

LL cos,0,sin

r

l

l

L

xy

Ln

L

c

Rt

coscos12

12

0,0,11 b

nbe

12nee

21

1

eEEHor 2

eEEVer

sincosexp1exp

ii

t

Ri

J.S. Nodvick and D.S. Saxon, Phys. Rev., 96, (1954), 180



yxVerVer

dddd

Pd

d

dPx

x

y

y

2

2

2

2

2

l

,1 zHor

Coh

Hor FNNNd

dP

d

dP

ll

l

l

l

dFNNNd

dPP z

Horz

Coh

Hor 2

2,1

2

1

22

4 Hor

Hor Edd

Pd

22

4 Ver

Ver Edd

Pd

yxHorHor

dddd

Pd

d

dPx

x

y

y

2

2

2

2

2

l

,1 zVer

Coh

Ver FNNNd

dP

d

dP

ll

l

l

l

dFNNNd

dPP z

Verz

Coh

Ver 2

2,1

2

1

Theory of Coherent radiation



TR 3D Form-Factor

the form factor for TR has view:

22

( ) exp sin zkf k k r

where – wave number, - observed angle, -the velocity of

electron in the units of speed of light k

2 2

2 2

1 ( )( , ) exp

2 2

x yg x y

r r

2

2

1( ) exp

22 zz

zh z

For a Gaussian bunch with transverse distribution

and the longitudinal distribution



Coherent radiation Spectrum

22 2|| 2

2 2 2 2 2

sin cos sin( ) cos


edW d d

c



Propagation of power Interference factor of the grating Structural factor of the grating

Smith – Purcell radiation



ve

h

d a

0

k k

q = 2q0ln =

d

n

1

b- cosq

æ

èç

ö

ø÷

ratio = da

22semiplaneRDR

cell N

d Wd WF F

d d d d

Radiation distribution from a semiplane

Strip (cell) geometry factor

Interference factor

2 24 sinh se ixp n22

cellF

0 0 2 2sins

1/ co

x

a

l

0

0

0/ cos2 coscos y

a

l

00

new

00; 2x y

Direction of the mirror reflection from a strip.



Smith – Purcell effect as resonant diffraction radiation, A.P. Potylitsyn, NIM B 145 (1998) 60 – 66.

x

y

θ =0 deg;

θ =90 deg;

γ=20;

h=0.15 mm;

a=d=12 mm;

N=20

Optimization of the strip tilt angle



Pyroelectric detector

Bolometer

Golay cell detector

Rectifier-type detector

Time Constant (Not measured for each detector) ~ 1 microsecond (depending on conditions of measurement) 02 March 2021



Bolometer and Pyroelectric detectors



Golay cell and Diode detectors



Injection 1-st turn 2-nd turn

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

SB

D, V

0.00 460 920 1380

Time, s n

a

-2 0

Time, s n

-0.005

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

SB

D, V

-1 21

Figure 5a. Typical Oscilloscope traces of

the SBD signal for the ATF DR injection.

Typical SBD oscilloscope trace

1 ns

Radiation pulse duration is ~ 10 ps !!!



0.00 1.20x10-7

2.40x10-7

3.60x10-7

4.80x10-7

6.00x10-7

-0.002

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

0.018S

BD

, V

Time, sFigure 38.

Figure 39. -11.2

0n

-5.6

0n

0.0

0

5.6

0n

11.2

0n

16.8

0n

22.4

0n

28.0

0n

33.6

0n

39.2

0n

44.8

0n

50.4

0n

56.0

0n

61.6

0n

67.2

0n

0.000

0.007

0.014

SB

D, V

Time, s

Figure 40.

453.6

0n

459.2

0n

464.8

0n

470.4

0n

476.0

0n

481.6

0n

487.2

0n

492.8

0n

498.4

0n

504.0

0n

509.6

0n

515.2

0n

520.8

0n

526.4

0n

0.000

0.006

0.012

SB

D,

V

Time, s

20 bunch/train ATF DR injection The time separation between bunches in this case - 2.8 ns.

Small build-up

SBD speed performance measurements





to detector

movable

4(1 cos[ ])

total

sI I

l

For 1THz =0.3 mm l

2 ST

l

- period of cosines;

For good approximation ~20 experimental data point per autocorrelation period

will be needed, so for 1THz the mirror M5 should be moved with the step of

7.5m.

Michelson Interferometer

02 March 2021

The Michelson Interferometer is a

Fourier Transform Spectrometer



Fourier Transform Spectrometer Interferogram





Martin Puplett interferometer



Bunch shape reconstruction Comparison of M-P-I and M-I

• Differential detection of two

polarizations gives better S/N

• Detected intensity is equal to input

intensity (past first polarizer) and

provides good input signal normalization



Additional references General measurements of brightness and emittance

C. Lejeune and J. Aubert, “Emittance and Brightness, definitions and measurements”, Adv. Electron. Electron Phys.,Suppl. A 13, 159 (1980).

O. R. Sander, “Transverse Emiitance: Its Definition, Applications, and Measurements” in “Accelerator Instrumentation”, E. R. Beadle and V. J. Castillo, edts., (AIP CP212, 1991) pp. 127-155.

R. Becker and W. B. Herrmannsfeldt, “Why pi and why mrad”, Rev. Sci. Instrum. 77(2006).

A. Wu Chao, M. Tigner “Handbook of Accelerator Handbook of Accelerator Physics and Engineering Physics and Engineering” World Scientific

C. A. Brau “What Brightness means” in The Physics and Applications of High Brightness Electron Beam”, World Scientific, p.20

M. Reiser, “Theory and design of charged particle beams”, Wiley‐VCH

Shyh‐Yuan Lee, “Accelerator Physics”, World Scientific

J. Clarke “The Science and Technology of Undulators and Wiggles” Oxford Science Publications

H. Loos, “Diagnostic Systems for High Brightness Electron Injectors”, talk at 48thICFA Advanced Beam Dynamics Workshop on Future Light Sources, SLAC 2010

B.E.Carsten et al., ” Measuring emittance of nonthermalized electron beams

from photoinjectors” Nuclear Instruments and Methods in Physics Research A 331 (1993) 791-796

K.T. McDonald and D.P.Russel “Methods of emittance measurememnts”, Frontiers of Particle Beams Observation Diagnosis and Correction (1988), Volume: 08544, pp.1-12

M.P. Stockli “Measuring and Analyzing Transverse Emittances of Charged Particle Beams”, talk at BIW’06, Fermi National Accelerator Laboratory, Batavia, IL, May 1, 2006

C.P. Welsch “Low energy beam diagnostics developments within DITANET”, Proceedings of 2011 Particle Accelerator Conference, New York, NY, USA, MOP186

M. Minty, F. Zimmermann, “Measurement and control of charged particle beams”, Springer (2003)

Facilities:

P. Emma, A. Brachmann, D. Dowell, et al., “Beam brightness measurements in the LCLS Injector”, Compact X-RAY FELs using High-Brightness Beams, Aug.5-6, 2010, LBNL

A. H. Lumpkin et al. “High-brightness beam diagnostics for the APS linac”, Proceedings of the 1999 Particle Accelerator Conference, New York, 1999, pp.2134-2136

N.Terunuma “KEK ATF beam instrumentation program”, Proceedings of 2011 Particle Accelerator Conference, New York, NY, USA, WEODN2

J. Frisch et al.,“Beam measurements at LCLS”, BIW08, MOIOTIO02

R. Boni et al., “Activities on high brightness photo-injectors at the Frascati laboratories, Italy”, Proceedings of LINAC08, Victoria, BC, Canada, pp.618-620

X.J. Wang and I. Ben-Zvi, “High-Brightness Electron Beam Diagnostics at the ATF”,

Proceeding of BIW’96, AIP Conference Proceeding 390 (1996) 232-239.

Slit technique

A.Cianchi et al., “High brightness electron beam emittance evolution measurements in an rf photoinjector”, Physical Review Special Topics Accelerator and Beams 11, 032801, 2008

M.Ferrario et al., “Direct Measurement of the Double Emittance Minimum in the Beam Dynamics of the SPARC High-Brightness Photoinjector”, PRL 99, 234801 (2007)

D. Filippetto, “A robust algorithm for beam emittance and trace space evolution reconstruction” SPARC Note SPARC/EBD-07/002.

S. G. Anderson et al., ” Space-charge effects in high brightness electron beam emittance measurements”, PRST-AB, v 5, 014201 (2002)

R. Thurman-Keup et al., ” Transverse emittance and phase space program developed for use at the Fermilab A0 photoinjector”, Proceedings of 2011 Particle Accelerator Conference, New York, NY, USA, MOP226

S. Wojcicki, K.Friedel, „Systematical error of the measurement of electron beam emittance“,Vacuum, vol.51, Nr. 2, pp 113-118, 1998

M.P. Stockli et al., ”Self-consistent, unbiased exclusion methods of emittance analysis”, Proceedings of the 2003 Particle Accelerator Conference, pp.527-529

Multi –screen, quad technique

P. Castro, “Monte Carlo simulation of emittance measurements at TTF2”, DESY Technical Note 03‐03 , 2003 (21 pages)

C. Limborg et al., “A modified quadscan technique for emittance measurement of space charge dominated beams”, Proceedings of. PAC 2003, pp 2667 - 2669

Beam size measurements, screens, cameras

Mini Workshop on "Characterization of High Brightness Beams“, DESY Zeuthen 2008, (https://indico.desy.de/conferenceDisplay.py?confId=806)

A. Murokh et al., “Limitations on measuring a transverse profile of ultradense electron beams with scintillators”, Proceedings of the 2001 Particle Accelerator Conference, Chicago, pp.1333-1335

A. Murokh et al., Proceedings of the 2nd ICFA Advanced Accelerator Workshop, 564-580 (2000)

A.H. Lumpkin et al., Nucl. Instr. and Meth. A 429, 336-340 (1999)

S.Rimjaem et al., “Comparison of different radiators used to measure the transverse characteristics of low energy electron beams at PITZ”, DIPAC2011, TUPD54



Additional references Tomography

A. C. Kak and Malcolm Slaney, Principles of Computerized Tomographic Imaging, IEEE Press, 1988.

D. Stratakis et al, “Tomography as a diagnostic tool for phase space mapping of intense particle beam”, PRSTAB, 9, 112801 (2006)

C. B. McKee, P. G. O'Shea, J. M. J. Madey, “Phase space tomography of relativistic electron beams”, NIM A, Volume 358, pp 264-267,

V. Yakimenko et al., “Electron beam phase-space measurement using a high-precision tomography technique”, PRSTAB, vol.6, 122801 (2003)

J. G. Power “SLIT SCATTERING EFFECTS IN A WELL ALIGNED PEPPER POT”, Proceedings of the 2003 Particle Accelerator Conference, pp.2432-2435

H. Zen et al., “Quantitative evaluation of transverse phase space tomography”, Proceedings of the 27th International Free Electron Laser Conference, pp. 592-594

Longitudinal diagnostic, RFD

T. Watanabe et al, “Overall comparison of subpicosecond electron beam diagnostics by the polychromator, the interferometer and the femtosecond streak camera”, NIMA, 480 (2002) 315–327

P. Emma, J. Frisch, P. Krejcik,”A Transverse RF Deflecting Structure for Bunch Length and Phase Space Diagnostics “, LCLS TN 00 12, 2000

D. Alesini, “RF deflector based sub ps beam diagnostics: application to FEL and advanced accelerators”, International Journal of Modern Physics A, 22, 3693 (2007)

C.P. Welsch “Development of longitudinal beam profile diagnostics within DITANET”, Proceedings of 2011 Particle Accelerator Conference, New York, NY, USA, MOP185

M. Hüning et al., “Observation of femtosecond bunch length using a transverse deflecting structure”, Proceedings of the 27th International Free Electron Laser Conference, pp.538-541

S. Zhang et al., “Temporal characterization of electron beam bunches with a fast streak camera at JLAB FEL facility”, Proceedings of the 27th International Free Electron Laser Conference, pp.640-642.

H.Loos et al., “Experimental studies of temporal electron beam shaping at the DUV-FEL accelerator”, Proceedings of the 27th International Free Electron Laser Conference, pp.632-634.

H.Loos, “Longitudinal diagnostics for short electron beam bunches”, SLAC-PUB-14120

S.J. Russel et al., ” Subpicosecond Electron Bunch Diagnostic”, LA-UR-2000-2135

Slice emittance

D. H. Dowell et al., ” Slice Emittance Measurements at the SLAC Gun Test Facility”, SLAC-PUB-9540, September 2002

M. Roehrs, et al., “Measurement of slice-emittance using transverse deflecting structure”, Proceedings of the 27th International Free Electron Laser Conference, pp.541-543.

I. Ben-Zvi et al. Picosecond-resolution slice emittance measurement of electron-bunches. In Proceedings of PAC1997, pp.1971-1973

1997.

Optical, laser techniques, EOS, laser wire

I.Wilke et al., “Single‐Shot electron beam bunch length measurements” PRL, v.88, 12 (2002)

G. Berden et al., “Electo‐Optic Technique with improved time resolution for real time, non destructive, single shot measurements of femtosecond electron bunch profiles, PRL v93, 11 (2004)

B. Steffen, “Electro‐optic time profile monitors for femtosecond electron bunches at the soft x-ray free electron laser FLASH“, PRSTAB, 12, 032802 (2009)

I. Agapov, G. A. Blair, M. Woodley, “Beam emittance measurement with laser wire scanners in the International Linear Collider beam delivery system”, PRSTAB, 10, 112801 (2007)

T. Shintake, “ Proposal of a nanometer beam size monitor for e+e linear collider”, NIM A311, (1992) p.453

M. Castellano, “A New Non Intercepting Beam size Diagnostics Using Diffraction Radiation from a Slit”, NIM A394, 275, (1997)

P. Karataev et al., “Beam-Size Measurement with Optical Diffraction Radiation at KEK Accelerator Test Facility”, Phys. Rev. Lett. 93, 244802 (2004)

E. Chiadroni, M. Castellano, A. Cianchi, K. Honkavaara, G. Kube, V. Merlo, F. Stella, “Non-intercepting electron beam transverse diagnostics with optical diffraction radiation at the DESY FLASH facility”, NIMB 266 (2008), pp.3789–3796

B.Steffen et al., “Spectral decoding electro-optic measurements for longitudinal bunch diagnostics at the DESY VUV-FEL”, Proceedings of the 27th International Free Electron Laser Conference, pp.549-551

N. H. Matlis et al., ” Electron bunch characterization using temporal electric-field cross-correlation”, Proceedings of 2011 Particle Accelerator Conference, New York, NY, USA, MOP229

D. Sütterlin, “Single-shot electron bunch length measurements using a spatial auto-correlation interferometer”, Proceedings of the 27th International Free Electron Laser Conference, pp.648-650

R. B. Fiorito, “Recent Advances in Beam Diagnostic Techniques”, Advanced Accelerator Concepts: Tenth Workshop. AIP Conference Proceedings, Volume 647, pp. 96-105 (2002).

J. Yang et al., “Spatial and temporal diagnostics of a high-brightness electron beam by technique of laser Thomson scattering”, Review Of Scientific Instruments, vol.73, Nr.4, April 2002

B. X. Yang and A. H. Lumpkin, “Simultaneous measurement of electron beam size and divergence with an undulator”, Proceedings of the 1999 Particle Accelerator Conference, New York, 1999, pp.2161-2163



Summary

• High brightness electron beams require particular diagnostic for longitudinal and

transverse phase space characterization:

– Strong energy dependency (YAG for low energies, OTR – for high energies)

– Non-invasive techniques are highly desirable

– Slice parameters measurements are important

• Any accelerator (linear or circular) also requires core diagnostics:

– Monitor beam position (BPMs)

– Monitor beam charge (CTs)

– Monitor beam profile (Screens)

• Nowadays many Labs extensively using Coherent radiation, in this case they are:

– Choosing the most appropriate generation way (Radiation type).

– Measuring radiation intensity distribution (Detectors)

– … or even a bunch length (a few possibilities), which is usually related to the

radiation power spectrum (Interferometer , …)



Materials

• In this presentation I used materials from:

– Xavier Artru (LAL)

– John Byrd (ANL)

– M. Shevelev (TPU)

– A. Konkov (TPU)

– P. Karataev (RHUL)

– L. Bobb (RHUL, Diamond)

– U.S. Particle Accelerator School



THANK YOU FOR YOUR

ATTENTION



Documents

BEAM DIAGNOSTICS AND RADIATION DETECTION SYSTEM