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12 years INRNE Hi-Tech HEP Group in the Accelerator Physics

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12 years INRNE Hi-Tech HEP Group in the Accelerator Physics

G. Asova, I. Tsakov, I. Bonev

Institute of Nuclear Research and Nuclear Energy

Bulgarian Academy of Science

- Hi-Tech group in INRNE
- Activities
- Activities in DESY
- Results

- Photo-Injector Test Facility at DESY in Zeuthen
- Transverse phase space diagnostics
- Single slit scan with EMSY
- Tomographic reconstruction
- Examples with experimental data

- Transverse phase space diagnostics
- Summary

Asova, Tsakov, Bonev

- A small but active group was created around the INRNE Innovation Bureau “INRNE Hi-Tech High Energy Physics Group”.
- Found in the mid 1990-s by Assoc. Prof. Dr. Ivan Tsakov
- Specialized on design and mass production of specific unique scientific apparata for experiments and application in the field of HEP experiments and accelerator physics for JINR, CERN and DESY

Asova, Tsakov, Bonev

DESY Zeuthen

DESY Hamburg

- Members working on hardware, software, mechanics, theoretical and experimental physics
- ‘Sphere’ and ‘Becquerel’ in JINR
- CMS, ATLAS, CLOUD in CERN – core software, design and construction
- HERA-B, H1, FLASH and PITZ in DESY – design and operation of measurement devices, data analysis

- Co-authors of more than 70 papers and conferences proceedings
- 3 PhD theses defended, 2 are in final stage of preparation
- 5 bachelors and 5 masters theses finisheduntil now

Asova, Tsakov, Bonev

- Good international reputation -due to achieved results and group activity and under the invitation by the INRNE Director Prof.J. Stamenov, CoresspondingMember of BAS, our group has been visited by a lot of wellknownphysicists as Prof. Malakhov, Prof. Krasavin, Prof. Rusakovich, Prof. Shelkov, Prof.Golutvin, Prof.Kadyshevski, Dr.Klein, Dr.Pitzl,Dr.Jenni, Dr. Walter, Prof.Wagner,
Dr.Kirkby, Dr. Stephan, etc.

- Dr.U.Gensch, DESY Zeuthen director representative, visit in 2003 Sofia →the INRNE became a member of thePhoto-InjectorTest Facility at DESY in Zeuthencollaboration
- financial support by the VI-th Framework Program
- further activity endeavored by F. Stephan,
PITZ spokes person, Sofia 2009

- Dr.Trinesand Dr. Brinkmann, DESY
directorate representatives, visit → INRNE

involved in the DESY FLASHproject

- 2007 visit of the current BAS President
Acad. N. Sabotinov in DESY

→ involving BAS in the European XFEL

Asova, Tsakov, Bonev

- DESY director Prof. A. Wagner – talk on the XFEL purposes and possibilities
- Mrs. Ekaterina Vitkova, Science
and Education Minister → General Agreement,

BAS involved in the XFEL, 2008

- Mrs. Ekaterina Vitkova, Science
- 14 devices developed and finalized under contracts with Dubna JINR, CERN, DESY on the base of signed protocols with
- JINR Laboratories of HEP, Radiobiology, Nuclear Problems
- DESY HERA-B and H1 gas systems, PITZ, FLASH, XFEL

Minister Vitkova, Prof. Stamenov,

Acad. Sabotinov, Prof. Wagner, Dr. Tsakov

Asova, Tsakov, Bonev

RF waveguide dry air system, XFEL

4 Emittance Measurement Systems EMSY, PITZ

→ 2 PhDs defended

Prof. Stamenov, I. Tsakov, F. Stephan, G. Trowitzsch

Dipl. Eng, I. Bonev

Asova, Tsakov, Bonev

Booster

p ~ 30 MeV/c

Gun & solenoids

60 MV/m

p ~ 7 MeV/c

Cs2Te photocathode

Transverse emittance (EMSYs, quadrupoles)

Characterization and optimization of high brightness sources for linac based FELs like FLASH and the XFEL

Asova, Tsakov, Bonev

emittance dominated beamlets → linear transport is valid

Image courtesy L. Staykov

- direct measurement for space-charge dominated beams
- sensitive to signal to noise, especially for lateral beamlets → low-charge limited
- applicable to relatively low energies (due to divergence)
- not 2D simultaneously

Asova, Tsakov, Bonev

10

preliminary results

- Laser temporal profile: 2.1/23.1/2.4 ps
- Laser spot size = 0.36 mm

3.0

x’ [mrad]

2.5

y=1.26 um

ey=1.26 mm mrad

2.0

e mm mrad

1.5

y’ [mrad]

1.0

Xemit

Yemit

0.5

x=0.76 um

ex=0.76 mm mrad

XYemit

0.0

378

380

382

384

386

388

390

392

394

Imain, A

min. exy = 0.98 mm mrad 100% RMS emittance

- F. Stephan, High Brightness Beam Measurements @ PITZ, Maui 2009
- Major part of the analysis L. Staykov, beforehand V. Miltchev

Asova, Tsakov, Bonev

Asova, Tsakov, Bonev

- J. Radon (1917) – reconstruction of an N-dimensional object from an infinite set of its (N-1)-dimensional projections◊
- Full 2p rotation of the object in small equidistant angular steps

- [Math. Phys, Klasse 69: 262-277]
- IEEE transactions 1986

Asova, Tsakov, Bonev

FODO cell

(focusing – drift – defocusing – drift)

- equidistant angular steps between the screens for both planes → 2D
- rms spot size is uncharged
- the beam parameters at the entrance of the lattice are adjusted
- the data treatment assumeslinear transport between the screens

Asova, Tsakov, Bonev

z

Position of reconstruction

Identical cell

cell length 0.76 m

quadrupole: max g = |6 T/m|, Leff = 0.043 m

phase advance f = 45°

p = 15 – 40 MeV/c

Q = 1 nC

e = 1 mm mrad → The beam is space-charge dominated in the full energy range. Still, linear transport is needed.

Asova, Tsakov, Bonev

Applicability of different algorithms to limited data sets

- N rotations → N projections of the (x, y)
- Which algorithms are applicable to small N? → N = 4

Backprojection

Filtered backprojection

Algebraic reconstruction

Maximum entropy

@ UMER, PITZ?

@ FLASH, PITZ

C++ & ROOT code developed for PITZ

Asova, Tsakov, Bonev

MAD* by

ASTRA** bx

Quadrupole strength k should be defined so that it guarantees periodicity along the FODO lattice.

Δx,y < 1 %

→

Δex = 0.07 %

e = 1.2 mm mrad , p = 32 MeV/c, dE/E << 1%

Asova, Tsakov, Bonev

* Methodical Accelerator Design

** A Space charge Tracking Algorithm

MAD by

ASTRA bx`

Δx = 6 %

Δy = 3 %

→

Δex = 2.5 %

e = 1.2 mm mrad , p = 32 MeV/c, dE/E << 1%

Asova, Tsakov, Bonev

2 magnets needed

booster

Quad Q1

Quad Q3

screen

EMSY1

varied

fixed

Measure emittance

5.15 m – position of reconstruction and then transport to EMSY1

Observation screen has to be the closest to the position of reconstruction

Asova, Tsakov, Bonev

13 projections

ex, N = 1.885 mm mrad

ex, N = 1.823 mm mrad

19 projections

Asova, Tsakov, Bonev

23 ps FWHM, RT/FT = 2.3ps

0.5

0

-0.5

-2

0

2

Solenoid current corresponding to the measured minimum emittance

Slit scan

Tomography

ex, N = 1.07 mm mrad

ex, N = 1.39 mm mrad

- Common features in both distributions
- the reconstruction shows bigger area where charge can be distributed

Asova, Tsakov, Bonev

385 A, EMSY, 0.5 % intensity cut

0.5 % intensity cut → 5 pC

Slit scan

Tomography

0.5

0

-0.5

-2

0

2

ex, N = 1.07 mm mrad

ex, N = 1.37 mm mrad

- Common features in both distributions
- elongated non-symmetric tales
- non-symmetric density of the core

Asova, Tsakov, Bonev

sxx' = 0.08 mm mrad

ex, N = 0.99 mm mrad

sxx' = 0.04 mm mrad

ex, N = 1.18 mm mrad

sxx' = 0.1 mm mrad

ex, N = 1.13 mm mrad

sxx' = 0.17 mm mrad

ex, N = 1.33 mm mrad

Asova, Tsakov, Bonev

Colleagues actively participating in measurements / new design:

- LAL Orsay:M. Jore, A. Variola
- LASA Milano:P. Michelato, L. Monaco, D. Sertore
- LNF Frascati:D. Alesini, L. Ficcadenti
- MBI Berlin:G. Klemz, I. Will
- TU Darmstadt:E. Arevalo, W. Müller
- Uni Hamburg:J. Rönsch
- YERPHI Yerevan:L. Hakobyan, M. Khojoyan

- DESY, Zeuthen site:J. Bähr, A. Barnyakov*, H.J. Grabosch,
Y. Ivanisenko, M. Hänel, M. Krasilnikov,

M. Nozdrin**, M. Mahgoub, B. O’Shea***, M. Otevrel, B. Petrosyan, S. Riemann,

S. Rimjaem, A. Shapovalov****, F. Stephan, G. Vashchenko

- DESY, Hamburg site:A. Brinkmann, K. Flöttmann, S. Lederer,
D. Reschke, S. Schreiber

- BESSY Berlin:R. Ovsyannikov, D. Richter, A. Vollmer
- CCLRC Daresbury:B. Militsyn
- INRNE Sofia:G. Asova, I. Bonev, K. Boyanov, L. Staykov, I. Tsakov
- INR Troitsk:A.N. Naboka, V. Paramonov, A.K. Skassyrskaia, A. Zavadtsev

* on leave from BINP, Novosibirsk, Russia** on leave from INR, Dubna, Russia*** on leave from UCLA, USA**** on leave from MEPHI, Moscow, Russia

- Acknowledgements: R. Brinkmann, U. Gensch, J. Knobloch, L. Kravchuk, V. Nikoghosyan, C. Pagani, L. Palumbo, J. Rossbach, W. Sandner, S. Smith, T. Weiland, G. Wormser

The work had partly been supported by the European Community, contract numbers RII3-CT-2004-506008 and 011935, and by the 'Impuls- und Vernetzungsfonds' of the Helmholtz Association, contract number VH-FZ-005.

Asova, Tsakov, Bonev

Zlatka Staykova, preparing PhD

Galina Asova, preparing PhD

Vladimir Arsov

Dimitar Mladenov

Anton Stoichev

Rositsa Gergova

Nikolai Evtimov

Lachezar Yotov

Hristo Yotov

Tihomir Plachkov

Konstantin Boyanov

Ivan Tsakov

Ivan Bonev

Filip Mladjov

Ivan Vlaev

Plamen Manchev

Velizar Miltchev, PhD defended

Kaloyan Krastev, PhD defended

Alexander Aleksandov

Gancho Dimitrov

Kalin Nankov

Lazar Staykov, PhD defended

Asova, Tsakov, Bonev

- Main Hi-Tech Group activity in development and production of unique scientific apparata
- Knowledge on beam dynamics and measurement techniques

- Tomography module being installed @ PITZ
- Different reconstruction algorithms tested
- 2 different sets of measurements used for reconstruction
- 0.5 nC, Gaussian pulse
- 1 nC, flat-top temporal profile compared to the standard slit scan
- specific features of the phase spaces can be seen with both methods

Asova, Tsakov, Bonev

MAD by

ASTRA bx

Quadrupole strength k should be defined so that it guarantees periodicity along the FODO lattice.

Matching deals easier with the Twiss parameters since the phase advance is a function of the Twiss b.

- Assume only linear external focusing:
- do the matching with Methodical Accelerator Design (linear transport)
- track with A Space-charge Tracking Algorithm

Asova, Tsakov, Bonev

For which f the calculated emittance has the smallest relative error with respect to a simulated one?

- 4 screens → f = p/4

De depends systematically on:

- Beam size errors – for which phase advance the deviation of the calculated emittance from a predefined one is the smallest, assuming different beam size errors are possible

f = 45° => fixed Twiss on screens:

e = 0.9 mm mrad , p = 32 MeV/c

Asova, Tsakov, Bonev

Original

MAD by

ASTRA bx

Including particles’ repulsion.

Δex = 8 %

Asova, Tsakov, Bonev

ex, N = 1.515 mm mrad

ex, N = 1.823 mm mrad

ex, N = 1.65 mm mrad

Measured

Reco from ASTRA projections

Original ASTRA

Asova, Tsakov, Bonev

Measured

Reco from ASTRA projections

Original ASTRA

ex, N = 1.77 mm mrad

ex, N = 1.823 mm mrad w.o. cut

(3 %)

ex, N = 1.115 mm mrad

ex, N = 1.515 mm mrad w.o. cut

(26 %)

ex, N = 1.65 mm mrad

Asova, Tsakov, Bonev

Smaller emittance

Asova, Tsakov, Bonev

1

0

-1

-1

0

1

The second RED axes are scaled to the ASTRA and quad scan axes

sx = 0.615 mm

sx' = 0.119 mrad

sxx' = -0.034 mm mrad

ex, N = 1.823 mm mrad

sx = 0.49 +/- 0.01 mm

sx' = 0.03 +/- 0.001 mrad

sxx' = 0.01 +/- 0.005 mm mrad

ex, N = 0.913 +/- 0.025 mm mrad

Such a discrepancy is still not conclusive since there is a single complete measurement.

Asova, Tsakov, Bonev

- Slide 7 celiq, 8, 9, 10, 11, 12, 13, 14, 23, 24, 27 celite
- Sledwa Velizar i Lazar za EMSYtata – napraweno, 1-2 slaida
- Tomographiq – predimstwa w srawnenie s emsy, design, ochakwani rezultati, s/w

Asova, Tsakov, Bonev