Diagnostics Experts of European Light Sources Workshop [DEELS]

10 Jun 2024, 08:30 → 11 Jun 2024, 18:00 Europe/Paris

Principal/1-32 - Salle A2.1.32/Libra (Batiment Principal)

Synchrotron SOLEIL is honored to host the 11th "Diagnostics Experts of European Light Sources" (DEELS) workshop.

The goal of the workshop is to bring the diagnostics community together to discuss common problems, share new developments, and enhance synergies between different facilities.

There is no registration fee. Accomodation and transportation costs shall be covered for each participant by their home institute.

We look forward to an enjoyable and productive exchange between all participants. As usual for DEELS, we are expecting that all institutes participating in the workshop contribute to the scientific program.

DEELS will be organized as a live 'in-person' event, and there will be no remote participation.

Important information : Registration  is closed. Due to practical constraints, we have to limit the maximum number of attendees to 28 people.

Monday, 10 June

08:30 Welcome coffee

Session 1

1 Welcome

Speaker: Nicolas HUBERT (SOLEIL)

Welcome_Hubert.pptx

2 BPMs design for ALBA II

As many other synchrotron light sources, ALBA is also going through an upgrade phase. One of the challenge is the miniaturization of many components among which BPMs.
In this contribution the development of BPMs for ALBA II from the design to the prototyping will be presented.

Speaker: Laura Torino (ALBA-CELLS)

ALBAII_BPMs_DEELS_2024-1.pdf

3 Evaluation of Individual Feedthroughs and Fully Assembled BPMs

To ensure the optimal performance of BPMs in synchrotron rings, particularly in PETRA IV, it is important to fully understand the evaluation process of individual feedthroughs and fully assembled BPMs. This involves grouping feedthroughs into sets of four with similar electrical properties and then, after assembling them into a complete BPM device, checking the electrical and mechanical centers. This presentation aims to demonstrate the results of both electrical and mechanical measurements of feedthrough and BPM prototypes for PETRA IV, and how they correlate with data obtained from CST simulations.

Speaker: Sergey Strokov (DESY)

2024_06_10_BPM_Fedthroughs_Evaluation.pdf

4 Beam Position Monitor Simulations with CST Studio

In order to accommodate the ever increasing expectations of the users, several third-generation Synchrotron light source facilities are going to be upgraded to the fourth-generation.
To achieve the target performance of such new machines, the design and validation stages related to the beam position monitor detectors have to be deeply investigated through numerical tools such as CST Particle Studio.
Taking advantage of CST's various kind of solvers, the contribution to machine's critical parameters, wake impedance and thermal load just to mention a few, can be evaluated and mitigated to reduce as much as possible their undesired effects on the machine's performance.
This presentation outlines the methodology used and the difficulties encountered during the various stages

Speakers: Moussa ELAJJOURI (SOLEIL), Dr Stefano Cleva (Elettra)

DEELS2024_CST_simulation .pdf

5 Investigation on an unexpected resonant mode affecting BPM measurements

Since the beginning of the ESRF-EBS storage ring in 2020, 11 BPM are affected by a phenomenon which generates un-physical position measurements, which depends on some beam parameter (mostly filling pattern and total current).

This issue is probably arising from a RF resonance at the BPM measurement frequency (352 MHz) present in the vicinity of the BPM block, inside the vacuum chamber. Early simulations done to find a possible resonant mode in this area were unsuccessful, indicating that subtle details of the vacuum chambers should be taken into account to explain the presence of such a mode.

After a deeper investigation, various measurements, tests and more advanced simulations, we now believe that we understand the origin of this resonance. We will show in this presentation how a resonance can occur even if the section of the vacuum chamber is not supposed to allow for it, the various measurements and tests which agree with this theory, and possible solutions to this issue.

Speaker: Benoit Roche (ESRF)

DEELS2024_ROCHE_v4.pdf

10:55 Coffee Break

Session 2

6 first results with new Bunch-by-Bunch acquisition system (Digit-500)

Four units of Digit-500 device have been delivered and are now being tested and used in both SR and Booster. In addition to the more classical use of (Bunch-by-Bunch) beam position measurements we are also exploring the possibilities of high quality (B-b-B) beam charge and even purity measurements by implementing dedicated firmware in the device.
Results are very recent and highly encouraging that will be presented.

Speaker: Mr Kees SCHEIDT (ESRF)

ESRF-new-BbB-acquisition-DEELS-2024-full.pdf

7 Libera XBPM Electronics for Future Light Sources

The current Libera Photon has been widely used in the past 8 years as an X-ray Beam Position Monitor. To meet the performance requirements of the last-generation light sources, additional features are requested, such as the interfaces to support Fast Orbit Feedback integration. Based on the requirements we are collecting from the field, we conceptualized a new solution and instrument platform to address this application. The aim of this contribution is to provide an overview of the new concept and to seek feedback from the community of users.

Speaker: Danilo Bisiach (Instrumentation Technologies doo)

Libera XBPM Electronics for Future Light Sources.pdf

8 Elettra 2.0 eBPM system architecture and its implementation in a complete Elettra section

In this contribution, we present the global system design for Elettra 2.0 eBPM, including machine timing signals and integration with the Elettra control system, and in particular how the new Global Orbit Feedback 2 (GOF2) has greatly simplified the entire software architecture.
The different functionalities/modalities (first turn, TbT, ecc) will be discussed as well as their implementation. Nevertheless, data acquired during dedicated machine shifts will be presented.

Speaker: Raffaele De Monte (Elettra Sincrotrone Trieste)

DEELS2024-Elettra-eBPM-DeMonte-V13.pptx

9 Discussion Trigger: Noise contributions in eBPM systems

Noise evaluation in modern eBPM systems for accelerators can be a difficult task, since their complexity allows a plethora of noise sources of different types.
To simplify the calculations during the system design, we propose to split the analysis into two sections: the pickups (as passive devices) and the front-end electronics including the conversion section (as active devices). In the former, modelled as receiving antennas, concepts such as noise temperature and impedance mismatch have to be taken into account, while in the latter other types of contributions such as like 1/f and quantization noise have to be considered.
We will present our findings during the development of the eBPM system for Elettra 2.0, with the aim of starting a fruitful discussion with the participants thanks to their experience in this field.

Speakers: Gabriele Brajnik (Elettra-Sincrotrone Trieste), Stefano Cleva (Elettra)

DEELS2024_Brajnik_Cleva.pdf

12:55 Lunch

Accelerator Visit

Session 3

10 Fast Orbit Feedback System implementation at Solaris

I present the implementation of an enhanced Fast Orbit Feedback (FOFB) system at the SOLARIS synchrotron and the adaptation of the existing Slow Orbit Feedback (SOFB) system to work in tandem without causing saturation of the FOFB corrector magnets.

I also discuss the adjustment of PID parameters and other high-time-resolution measurements to optimize the performance of the feedback system. The first measurements and tests demonstrate the system's capabilities, highlighting its effectiveness in maintaining beam stability and quality, including compensation for the impact of undulators (insertion devices) on the electron beam.

Speaker: Dr Roman Panas (NSRC SOLARIS)

FOFB_SOFB_FINAL_10_06_2024.pptx

11 Recent progress in PETRA IV orbit feedback design

The simulations for the PETRA IV upgrade project of the fast orbit feedback system are underway. The latest modeling and simulation results will be shown and discussed.

Speaker: Sven Pfeiffer (DESY)

SPfeiffer_DEELS_WS_final.pdf

SPfeiffer_DEELS_WS_final.pptx

16:20 Coffee Break

Session 4

12 Status and future of SOLEIL Fast Orbit Feedback

SOLEIL Fast Orbit Feedback has been running on its new platform for user beam since last January.

In this presentation, we will present its integration to the control system and its commissioning.

We have been using this new platform for further identification of the FOFB loop. We will discuss both the method and the results.

The envisioned developments for the future fast archiver will also be outlayed.

Speaker: Romain BRONES (SOLEIL)

240610_DEELS_RBS.pdf

240610_DEELS_RBS.pdf

13 New Storage Ring Air Temperature Monitoring System at Diamond Light Source

Fourth generation synchrotron light sources require significant advancements in beam stabiltiy, typically on the sub-micron scale. Consequently the performance specification of beam position monitors must similarly advance. This has lead to compensation schemes, used to mitigate position disturbances and drift from the environment, being implemented near the beginning of the rf chain i.e. downstream of the button pick-ups. Given that electronics are likely to be located in the tunnel in close proximity to the girders it is important to understand the environmental variations in these locations. For this purpose a new storage ring air temperature monitoring system has been installed at Diamond Light Source. Here a description of the system is presented with recent results.

Speaker: Lorraine Bobb (Diamond Light Source)

SR_AirTemp_LB.pdf

SR_AirTemp_LB.pptx

19:00 Workshop Dinner

Tuesday, 11 June

Session 5

14 The cSTART project: A unique storage ring with challenging beam diagnostics requirements

The cSTART project aims to demonstrate the injection of electron beams like from a Laser Plasma Accelerator (LPA) and storage of very short bunches in a very large acceptance storage ring. It will use the linac-based test facility FLUTE as a main injector at early phase and Laser plasma injectors (LPA) later. The combination and range of special beam parameters like low bunch charge (down to 1 pC) and ultra-short bunches (about 10 fs), in addition to the compact design of the arc sections, make it challenging to find commercially off-the-shelf beam diagnostics. In this presentation, I will illustrate the main challenges of the project from the beam diagnostics point of view and elaborate on each system.

Speaker: Dr Dima El Khechen (Karlsruhe Institute for Technology)

DEELS24_ElKhechen_version2.pdf

15 Electron Beam Instrumentation for SLS2.0

As of September 30th, 2023, the upgrade to the SLS storage ring has commenced. Some of the SLS diagnostics will be integrated with modifications to satisfy the requirements of SLS 2.0, including changes to their quantity, specifications, and technical implementations. Additionally, new diagnostics systems will be installed that have been tested at the SLS. After providing an update on the progress of the SLS 2.0 project, a technical overview of the diagnostic systems and the current progress will be presented.
Beam position monitors and feedback systems will not be the focus of this presentation.

Speaker: Cigdem Ozkan Loch (Paul Scherrer Institut)

SLS2Diag_DEELS242.pdf

16 Initial Results of X-ray Fresnel Diffractometry for Small Beam Sizes at Diamond Light Source

The feasibility of using X-ray Fresnel Diffractometry to measure small beam sizes beyond the resolution of the X-ray pinhole cameras is studied. X-ray Fresnel diffractometry employs a single slit with optimised width that produces a double lobe diffraction pattern. The visibility of this double lobe intensity distribution relates to the beam size and promises micron-scale beam size measurement. To test this method at Diamond, a screen produced by LIGA (i.e. X-ray lithography, electroplating and molding) with different slit widths is used. Numerical studies and SRW simulations were conducted to select the optimal photon energy for the available slit widths, the expected diffraction pattern for different beam sizes, and the required distances between the source-to-slit and slit-to-scintillator for the case of Diamond. Results, challenges, and future plans are presented.

Speaker: Niki Vitoratou (Diamond Light Source)

Xray-Diffractometry_DEELS_NV.pdf

17 Towards emittance measurements for SOLEIL-II: unexpected issues

In the frame of SOLEIL-II, we have attempted preliminary tests on SOLEIL-I of low vertical emittance measurements based on the standard pinhole camera imaging system. However, we rapidly faced an unexpected issue: the perturbation of the measurement by some "filaments". It seems that those filaments are due to a parasitic phase contrast imaging induced by our UHV Aluminium window. We will report on the characterization of those filaments, also observed at DLS and ESRF-EBS, the first solutions tested and our strategy to avoid such perturbation on SOLEIL-II.

Speaker: Marie LABAT (SOLEIL)

main_labat_v02.pdf

18 Discussion Trigger: Vertical emittance control / beam blowup

Techniques to increase and/or control the vertical emittance are necessary in current and future machine. Different techniques are used in different machines (white noise, side band excitation, coupling resonant excitation) with different results.
I would like to open a discussion on the methods and the coupling strength and beam centroid stability obtained in each machine.

Speaker: Laura Torino (ALBA-CELLS)

RoundBeamsTechnique.pdf

11:00 Coffee Break

Session 6

19 New interferometric aperture masking technique for full transverse beam characterization using synchrotron radiation

Emittance measurements using synchrotron radiation are usually performed using x-rays to avoid diffraction limits. Interferometric techniques using visible light are also used to measure either the horizontal or the vertical beam projection. Several measurements rotating the interferometry axis are needed to obtain a full beam reconstruction.

We present a new interferometric aperture masking technique and data analysis, inspired by astronomical methods, that are able to provide a full 2-D transverse beam reconstruction in a single acquisition. Results of beam characterization obtained at ALBA synchrotron light source will also been shown.

Speaker: Laura Torino (ALBA-CELLS)

NRA_DEELS_2024-1.pdf

20 Discussion Trigger: Interferometry with a fast gated ICCD camera at BESSY II

As BESSY II uses complex filling patterns for standard operation as well as other modes of operation, it is necessary to have bunch-resolved diagnostic tools. While a streak camera has been successfully used for the longitudinal electron-beam diagnostics a fast-gated ICCD camera is being implemented on the neighbouring beamline to provide bunch-resolved diagnostics in the transverse directions. Both beamlines use visible light from a bending magnet, which severely limits transverse diagnostic resolution using direct imaging. However, the use of optical interferometry can significantly increase the spatial resolution. Implementing the interferometric method with the fast-gated ICCD camera resulted in an unexpected behaviour of the measured interference patterns that differ from the corresponding results obtained with a slow CCD camera. In my talk, I will try to explain the problem in more detail with the aim of allowing a fruitful discussion to take place.

Speaker: Irma Shmidt (Helmholtz-Zentrum Berlin)

DEELs_2024_discussion.pdf

21 Beam Size Measurment With Synchrotron Radiation Monitor Along the Booster Energy Ramp.

In the scope of SOLEIL II, the booster must also be upgraded to reduce from 130 to 5 nm.rad the emittance of the beam delivered to the ring.
Control of the emittance in the booster will become crucial to ensure the nominal performance of the storage ring injection.
The SOLEIL I booster is already equipped with a Visible Synchrotron Radiation Monitor (MRSV). This equipment, made of an extraction mirror and a simple optical system, was originally planned to be used only for beam presence verification but has not been used routinely for operation since the commissioning in 2005.
The control and acquisition systems had been refreshed to be usable again and allow the beam size measurement along the booster energy ramp. Those measurements have been compared to simulations and give promising results, still, the beam size measured is always larger than predictions. We attribute this effect to the minimum exposure time of the camera (24 µs, i.e. ~45 turns in the booster) and beam position fluctuations, but to properly validate this hypothesis, we decided to use a new camera with a minimum exposure time of 1 µs (i.e. 1 or 2 turns). The first results were surprising and led to a detailed study of camera properties (pixel size, ...) and their interaction with optical properties like depth of fields. This discussion resumes the main results of the study.

Speaker: Alexandre MOUTARDIER (SOLEIL)

Deels2024_MRSV_Boo_AM.pdf

22 Discussion Trigger: CHARACTERISING POLARISATION AT THE BESSY II BOOSTER BEAMLINE

A third branch at the booster optical beamline has recently installed for research and development studies. Topic should cover beam characterisation and the accelerator physics university seminar. A CMOS camera aided by programble lens and mirrors replicate the existing source point imaging diagnostics.
During the studies it has been found that the polarisation shows non-linear behaviour.
This talk open the discussion of the present results.

Speaker: Pauline Ahmels (Helmholtz-Zentrum-Berlin)

hzb-polarization-deels-ahmels.pdf

13:00 Lunch

Session 7

23 Discussion trigger: Network boot experience and code sharing use-cases

Over the last few years some institutes had been using network boot on Libera instruments successfully. Latest OS release of platform B Libera instruments can be boot over network but some issues have been identified. What are most common issues, bottlenecks or experience in general from the community?
Secondly; libera software and its interfaces is becoming available to more and more users. To provide reliable and traceable service, I-Tech has introduced code sharing over Gitlab platform. Has any laboratory from the community used this platform before? What is community opinion on this approach?

Speaker: Mr Peter Leban (Instrumentation Technologies d.o.o)

presentation_DEELS_2024_Peter_Leban.pdf

severni_sij_deels.mp4

24 measurement of the ESRF 6GeV energy fluctuations

The 6GeV electron beam shows since long tiny variations of its energy that can now be measured by a suitable use & treatment of the horizontal position from (128) dispersive BPMs, and also more recently by a simple X-ray detector installed on an available X-ray beam port equipped with a 3-pole wiggler. These 2 fully independent results are now recorded permanently and their analysis allows to distinguish fine details of these variations that are often induced by urban activity in the Grenoble area.
The principle, the characteristics and the main components of these measurement systems will be described, together with the obtained results.

Speaker: Mr Kees SCHEIDT (ESRF)

ESRF-6GeV-Energy-Fluctuations-DEELS-2024-V1.pdf

25 DCCT Noise and Beam Lifetime Measurement

Beam lifetime measurements are an important tool to characterize the key storage ring and machine performance parameters. They are usually derived from the dc current transformer (DCCT) data, and their accuracy depends on DCCT noise and data duration period. However, accurate dc current and fast lifetime determination are in contradiction and have to be balanced carefully. In this contribution, a model is presented which relates the relative accuracy in lifetime determination and the DCCT noise with the acquisition time. For the PETRA IV project which aims to upgrade the present PETRA III synchrotron into an ultra low-emittance source, according to this model a lifetime determination to the level of 1% should be possible within 5-6 s acquisition time.

Speaker: Gero Kube (Deutsches Elektronen-Synchrotron DESY)

DEELS_Kube.pptx

26 Optical charge measurements at PETRA III

This talk will cover the development of a bucket resolved charge measurement based on synchrotron radiation in the optical regime. The topics are the selection of an adequate detector for short light pulses, the optical setup and the digital readout system. As the measurement is planned as an upgrade of the actual online measurement an overview on tasks and challenges of building a long term reliable system is given.

Speaker: Kai Demmler (DESY (Deutsches Elektronen-Synchrotron))

Demmler_DEELS2024_Talk.pdf

15:35 Coffee Closure