A Snapshot of CERN Beam Instrumentation R&D Activities
D. Alves louro, A. Boccardi, S. Jackson, T. Lefevre, F. Roncarolo, J. Storey, R. Veness, C. Zamantzas, CERN, Geneva, Switzerland

Abstract
The CERN accelerator complex stands out as unique scientific tool, distinguished by its scale and remarkable diversity. Its capacity to explore a vast range of beam
parameters is truly unparalleled, spanning from the minute energies of around a few keV and microampere antiproton beams, decelerated within the CERN antimatter
factory, to the 6.8 TeV high-intensity proton beams that race through the Large Hadron Collider (LHC). The Super Proton Synchrotron (SPS) ring plays also a crucial role by
Phase-II
EOvarious
beam-test
outlookslowly extracting protons at 400 GeV. These proton currents are then directed
towardtargets,
generating all sorts of secondary particle beams. These beams, inturn, become the foundation of a diverse fixed-target research program, enabling
scientificacross a wide spectrum. Moreover, as CERN looks ahead to future§ Opposing
pickupexploration
EO-BPM
being prepared for HiRadMat
studies involving electron-positron colliders, the development of cutting-edge diagnostics
tests in August for2021.low emittance and short electron pulses is also underway. This contribution§ Furtherplannedinatthe field of beam instrumentation.
serves as a snapshot, shedding light on the main R&D initiatives currently underway
at tests
CERN
CLEAR in winter 2021/22

Complex design of electromagnetic Pick-ups
High directivity cryogenic stripline BPM for HL-LHC

High bandwidth BPM using electro-optical pick-up

High frequencies BPM using dielectric pick-up

In-air pickup design
450GeV protons @ HIRADMAT
RF coax feedthroughthermal link

200MeV, ps long electron bunch @ CLEAR

aperturetransition

10

Stephen Gibson et altungsten
blockbodystripline
antennacooling capillary

High resolution beam size monitor using OTR PSF
Forward OTR

Simulations

15000
14000

0.250000
3.000000
5.750000
8.250000
11.500000
13.750000

12000

Intensity, arb. units

11000

Screen

10000
9000
8000

• Wire Breakage – why?
– Brittle or Plastic failure (error in motor control)– Melting/Sublimation (main intensity limit)

100 µm

Wire100 µm• Due to energy deposition in wire by particle beam7000

• Temperature evolution depends on

6000– Heat capacity, which increases with temperature!
– Cooling (radiative, conductive, thermionic, sublimation)

5000
4000
3000

• Negligible during measurements (Typical scan 1 ms & cooling time constant ~10-15 ms)

2000• Wire Choice1000

PSF @ 500nm

Low density materials foradvanced wires and screens

Limitation of Wire-Scanners

sconvoluted

13000

Backward OTR

State-of -the art in interceptive diagnostics-60-40-200204060

OTR vertical projection, umBeam~ 0,5 µm20m/s rotational Wire Scanner

600nm beam size measured @ ATF2-KEK in VUV range
Rhodri Jones – CERN Beam Instrumentation GroupCNT yarn before irradiation

Strips– Good mechanical properties, high heat capacity, high melting/sublimation point– E.g. Carbon which sublimates at 3915K

0CNT~ 20 nm

CNT yarn after irradiation @ HIRADMATCNTW multi-scale

Beam Instrumentation and Diagnostics - CAS 2019

Non-invasive beam size monitoring
Gas ionization monitor using hybrid pixel detector

Imaging system using fluorescence of supersonic gas curtainGas Jet

Hor. beam size/position evolution
during 1.2s long cycle @ PS

Diffraction radiation from high precision slits

LHC@6.8TeV

Diffraction Cherenkov radiation imaging system
mm hor. beam size @ CESRTAKEK-ATF2 target
220um 105um 80um 50um OTR

1.2GeVelectrons

5um beam size measured@ ATF2-KEK in VUV

1.2GeV electrons

5GeV
positronshor. beam size @ ATF2-KEK

Visible light SR interferometer @ LHC interferogramnanospheres

lens

light source

SRe- beam

𝑉𝑖𝑠𝑖𝑏𝑖𝑙𝑖𝑡𝑦𝑉𝑆𝑖𝑧𝑒𝜎speckles

λdetector𝑒"
𝑒!
𝑒!

𝐷𝑅𝑅!

𝑧slits••@Alba

Fully 2D, high-resolution
Suitable for X-rays

The probe: silica (SiO2) spheres,
500 nm, in water

SR X-ray interferometry using near field speckles

Measuring the longitudinal profile of short bunches
Streak Camera

Electro-optical sampling for sub-ps time domain measurement

Bunch spectrum measurement using Coherent Cherenkov
Diffraction Radiation

666ps bunch spacing

Measuring in 3 bands (60-84-113.5GHz)

6ps FWHM longbunch @ CLEAR

OTR@ linacs = 4.5ps (1.4 mm)

Prism

Measured at CLEAR/CERN. – 200Mev e-GaP

Bandwidth > 1GHzWinglet

Developing particle detectors for beam loss monitoringHigh sensitvity Ionisation chamber

Cherenkov in optical fiber as continuous BLM
SiPM

SiPM

Optical fibre (silica)
lerticaP

Beamoshr
we Cherenkov photons to the photo-sensor

Beam pipe and accelerator components

Dependence withfibre distance

Setup with two fibres @ CLEAR

Semiconductor as fast BLM

Capture angle

State-of-the art electronic development

16
System-on-Chip as
fast DAQ in the multi
Front-EndConversion Characteristic RFlow currents
Front-End Conversion Characteristic
mid-high currents

Rad-tol / Rad-hard Front-Ends

150.001

10-8100

5s integration

Measurement Relative Error [%]1

Measured Current [A]

1010 -5
10 -6
10 -7
10 -8-9

Measurement Relative Error [%]1s integration

10 -4

Measured Current [A]

0.100

10-10

10-11

0.010

10-12
10 -9

GSa/s

10

1

0.10

0.01

0.001
10 -9

10 -8

10 -7

10 -6
Injected Current [A]

10 -5

10 -4

0.001

10 -9

1. × 10-11

10 -8

10 -7

10 -6 -1010 -5
5. × 10 1. × 10-9
Injected Current [A]Injected Current [A]

0.001
10 -4
5. × 10-9 1. × 10-8

5. × 10-11 1. × 10-10

1. × 10-11

5. × 10-11 1. × 10-10

5. × 10-10 1. × 10-9

Next-Time stretch EO techniques for >100GSa/s

Moving Average vs. Equivalent Loss 2nd Order IIR filtering over the CFC counter data.
Averaging Window With = 5 s
Averaging Window With = 1 s
IIR Filter Resonance Frequency = 0.127 Hz (Eq. Loss Charge), Damping Factor = 1
IIR Filter Resonance Frequency = 0.637 Hz, Damping Factor = 1IIR Filter Resonance Frequency = 0.159 Hz (Eq. Rise 0-95%), Damping Factor = 10.8
0.6
0.4
0.2

1.00.8Output Signal

1.0

New BPM system @ SPS

5. × 10-9 1. × 10-8

Injected Current [A]Movingvs. range
Equivalent Loss 2nd Order IIR filtering over the CFC counter data.
BLM ASIC performance– 109Average
dynamicOutput Signal

Standardising
read-out platform

0.6
0.4
0.2

0.0

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time [s]Francesco Martina - 4th SY-BI Student and R&D Meeting

Francesco Martina - 4th SY-BI Student and R&D Meeting

0.0025/03/22

246810Time [s]25/03/22