BIW `06, May 1st 2006 Beam Diagnostics Challenges in the FAIR project at GSI The FAIR project - a Facility for Antiproton and Ion Research Planning of

BIW `06, May 1st 2006

Beam Diagnostics Challenges in the FAIR project at GSI

Beam Diagnostics Challenges in the FAIR project at GSI

The FAIR project - a Facility for Antiproton and Ion Research

Planning of FAIR beam diagnostics done by Peter Forck and Andreas Peters togetherwith the GSI BD group and collaborators

Beam Diagnostic Challenges in the FAIR Project 2Andreas Peters, Peter Forck

BIW `06, May 1st 2006

OutlineOutline

The FAIR project – a short introduction to the accelerator

parameters and the facility layout and operation modes as well

as the research aims

Challenges in the accelerator parameters

Linked general challenges for the beam diagnostic equipment

(diversity and dynamics)

Examples of beam diagnostic challenges in detail and R&D for

possible solutions:

Current measurement in SIS100 from dc to short single bunch

operation

BPM systems for the cryogenic synchrotrons with varying

acceleration frequencies

Turn-by-turn profile measurement (RGM) in synchrotrons and

storage rings with high repetition rates (MHz) under UHV

conditions

Summary and outlook


BIW `06, May 1st 2006

FAIR – Basic Layout and Parameters (1)FAIR – Basic Layout and Parameters (1)

Beams now:Z = 1 – 92(protons to uranium)up to 2 GeV/nucleonSome beam cooling

Beams now:Z = 1 – 92(protons to uranium)up to 2 GeV/nucleonSome beam cooling 100 m

TodayToday Future ProjectFuture Project

Beams in the future:Intensity: 100 – 1000 fold Species: Z = -1 – 92(anti-protons to uranium) Energies: up to 35 - 45 GeV/uPrecision: full beam cooling

Beams in the future:Intensity: 100 – 1000 fold Species: Z = -1 – 92(anti-protons to uranium) Energies: up to 35 - 45 GeV/uPrecision: full beam cooling


BIW `06, May 1st 2006


Final facility layout with all planned buildings

Tunnel for SIS100/300 at a depth of about 17m to comply with the requirements of radiation safety


BIW `06, May 1st 2006


Injector chainInjector chain

100 m

Main synchrotrons of FAIR:SIS100, 2T, pulsed sc. magnets,29 GeV, 4·1013 protons, 25 ns2.7 GeV/u, 1012 U28+-ions, 60 nsSIS300, 6T, pulsed sc. magnets,34 GeV/u, 4·1011 U92+-ions,slow extraction (1 – 100 s)

Main synchrotrons of FAIR:SIS100, 2T, pulsed sc. magnets,29 GeV, 4·1013 protons, 25 ns2.7 GeV/u, 1012 U28+-ions, 60 nsSIS300, 6T, pulsed sc. magnets,34 GeV/u, 4·1011 U92+-ions,slow extraction (1 – 100 s)

Booster synchrotron SIS18:2.7·1011 U28+-ions, 2.7 Hz5.4·1012 protons, 4 Hz

Booster synchrotron SIS18:2.7·1011 U28+-ions, 2.7 Hz5.4·1012 protons, 4 Hz

UNILAC (upgraded):15 emA U28+, 11.4 Mev/u

UNILAC (upgraded):15 emA U28+, 11.4 Mev/u

p-Linac (new):70 mA, 70 MeV

p-Linac (new):70 mA, 70 MeV


BIW `06, May 1st 2006


100 m

HESR: stoch. cooling up to14 GeV antiprotons, e-coolingup to 9 GeV, internal target

HESR: stoch. cooling up to14 GeV antiprotons, e-coolingup to 9 GeV, internal target

Targets and storage rings of FAIR:Targets and storage rings of FAIR:

SFRS TargetSFRS Target

CR: stochastic cooling of RIBs,and antiprotons, mass spectr.RESR: accumulation of anti-protons, fast decel. of RIBsNESR: e-cooling of RIBs andand antiprotons, precise massspectr., e-n scattering facility

CR: stochastic cooling of RIBs,and antiprotons, mass spectr.RESR: accumulation of anti-protons, fast decel. of RIBsNESR: e-cooling of RIBs andand antiprotons, precise massspectr., e-n scattering facility

Antiproton TargetAntiproton Target


BIW `06, May 1st 2006

Scheme of FAIR Parallel OperationScheme of FAIR Parallel Operation


BIW `06, May 1st 2006

Research Areas at FAIRResearch Areas at FAIR

100 m

Hadron Physicswith antiprotons

Nuclear Structure & Astrophysicswith radioactive beams

Plasma Physicswith compressedion beams & high-intensity petawatt-laser High EM Field (HI) ---

Fundamental Studies (HI & p)Applications (HI)

Nuclear Matter Physics with35-45 GeV/u HI beams


BIW `06, May 1st 2006

Challenges in the Accelerator Parameters (1)


Fast cycling superconducting magnets: For SIS 100 superconducting magnets (2 T)

with 4 T/s ramping rate are required. SIS 300 will be equipped with 6 T (1 T/s)

dipole magnets. The optimization of the magnet field quality for low loss, high

current operation with beams filling large parts of the acceptance is of great

importance.

Control of the dynamic vacuum pressure caused by beam loss induced desorption

of heavy molecules, which can cause the rapid increase of the residual gas

pressure a novel collimation concept is presently under test at the SIS18.

Cooled secondary beams: Fast electron and stochastic cooling at medium and at

high energies will be essential for experiments with exotic ions and with

antiprotons.

High RF voltage gradients: The fast acceleration and bunch compression of intense

heavy-ion beams down to ~60 nanosecond bunch length (protons: ~25 ns)

requires compact RF systems. Complex RF manipulations with minimum phase

space dilution and the reduction of the total beam loading in the RF systems are

important R&D issues.

Operation with high brightness, high current beams: The synchrotrons will operate

close to the space charge limits with tolerable beam losses of the order of a few

percent. The control of collective instabilities and the reduction of the ring

impedances is a subject for the R&D phase.


BIW `06, May 1st 2006



Straight section of the synchrotron tunnel with a shielded small recess building

Cross section of the synchrotron tunnel with an inner size of 5 x 4 m2, SIS100 (bottom) and SIS300 (top) cryostats are shown with cryogenic bypass lines (yellow)


BIW `06, May 1st 2006

General Challenges for Beam Diagnostics (1)


Despite quite different beam parameters of the FAIR synchrotrons and

storage rings, common realizations of SIS100, SIS300 and all storage ring

diagnostics are mandatory to save man-power and costs during the R&D

phase and enable a cost reduction due to the large quantities during the

construction phase.

Large dynamic range, e.g. in SIS100: from low currents beams for

adjustments up to space charge limited intensities of heavy ions, from

long bunches at injections up to short pulses after bunch rotation /

compression.

Because the acceptance was limited to 3*emittance (KV-Distribution) in

the synchrotrons and 2*emittance in the transfer lines , a precise

alignment of the beam in the vacuum pipe is strongly advised. The beam

diagnostics system has to allow a precise orbit measurement and the

capability for online feedback on the closed orbit, on the betatron tune,

on chromaticity and on coupling.

If the loss budget in the superconducting synchrotrons is only a few

percent, current measurements with high accuracy (~10-4) for controlling

beam losses are mandatory.


BIW `06, May 1st 2006



Due to the compactness of all accelerators the repetition rates are quite

high (up to the MHz region), which is a challenging task e.g. for turn-by-

turn profile measurements based on a RGM system.

Additional constraints have to be fulfilled, which are sometimes

challenging:

installations in cryogenic parts of the accelerators,

UHV conditions (pressure: 5×10-12 mbar) and

high radiation levels.

The complex, „quasi-parallel“ operation scheme demands a highly

reliable and flexible data acquisition system adapted to the fast pulsed

machines parameters.

Complicated scheme of transport lines with high diversity of magnetic

rigidities.


BIW `06, May 1st 2006



not part of thebeam lines

sc 100 Tmsc 90 Tm

18 Tm13 Tm

sc 300 Tm

SIS18

SIS300

Dump

CBMPP2

AP

CR

RESR

SFRSTarg

LE-Cave

HE-Cave

NESR

FLAIR

HESR

PP1 PbarTarg

SIS100

1

2 34

5 67

8

910

11

12 1314 15

16

17 18 1921

22 23

24

2526

27

28

29

20

30

31

32

3334

35

36

37

3839

40

4142

43 4445

46

D

A

BC

E F

G H I

J K LMN

O

P Q

R

ST

U

Schematic view of FAIR beam transport lines

Total length of about 2350 m of allbeam lines (excluding Antiproton-

Separator, FLAIR beam lines, ...), divided in 46 sections with differing parameters.

In the transfer lines the high dynamic range of intensities and energies as well as ion species leads to the necessity of destructive measurement methods needed for low currents and in parallel to non-destructive devices for high currents which would destroy any material in the beam optical path.


BIW `06, May 1st 2006

Beam Diagnostic Challenges in DetailBeam Diagnostic Challenges in Detail

Examples of beam diagnostic challenges concerning the ring

accelerators in detail and R&D for possible solutions:

(1) Current measurement in SIS100 from dc to short single bunch

operation (operating bandwidth of 10 kHz)

(2) BPM systems for the cryogenic synchrotron environment with

varying acceleration frequencies

(3) Turn-by-turn profile measurement (RGM) in synchrotrons and

storage rings with high repetition rates (MHz) under UHV

conditions


BIW `06, May 1st 2006

Current Measurement in SIS100 (a)Current Measurement in SIS100 (a)

Injection (4*stacking)

Protons U28+

Nmax 4*1013 5*1011

E [MeV/u] / trev [µs] 2000 / 3.81 92 / 8.72

Icoasting/Ibunch [A] 1.6 / 8 0.28 / 1.45

After acceleration

E [GeV/u] / trev [µs] 26 / 3.62 2.38 / 3.76

Icoasting/Ibunch [A] 1.8 / 8.8 0.6 / 3.2

After bunch merging & compression (h: 8 1, bunch length 25/60 ns)

Icoasting/Ibunch [A] 1.8 / 384 1.2 / 57

Theoretical upper limits of currents in SIS100


BIW `06, May 1st 2006

Current Measurement in SIS100 (b)Current Measurement in SIS100 (b)

Solutions: a) Use the NPCT of Bergoz; an installation in SIS18 is scheduled for August 2006 and tests starting in October 2006 – Question: Will the feedback loop of the NPCT work stable under high current bunched beam condition (bunch frequency of some MHz) ?

Severe problem of GSI DCCT: Above specific levels of beam current and/or revolution frequency the loop starts to oscillate (right). Mostly it gets back control. But: Did it settle to the correct working point ?


BIW `06, May 1st 2006

Current Measurement in SIS100 (c)Current Measurement in SIS100 (c)

Solutions: b) Design of an alternative current measurement based on the idea of a clip-on ampere-meter with a GMR sensor in the gap of a toroidal core (collaboration with University of Kassel, Germany).

Simulated magnetic flux in a slit toroidal coreScheme of an clip-on ampere-meter


BIW `06, May 1st 2006

Current Measurement in SIS100 (d)Current Measurement in SIS100 (d)

Assuming a measurement bandwidth of 10 kHz, the resolution of different GMR sensors is in the order of ~100 nT

Resolution measurement of different GMR sensors (by NVE corporation)


BIW `06, May 1st 2006

Current Measurement in SIS100 (e)Current Measurement in SIS100 (e)

Data sheet characteristics:

Saturation field: 10 mT

Specified linear range:± 0 – 7 mT

Operating frequency: dc 1 MHz

Example for the DC characteristics of a GMR sensor (NVE AA005)

Measurements concerning high frequency behaviour are under way !


BIW `06, May 1st 2006

Current Measurement in SIS100 (f)Current Measurement in SIS100 (f)

Construction of a first test set-up with a split core (either VITROVAC 6025 F or CMD 5005 from CMI ferrite) and two gaps for sensor positioning to be built in

SIS18 in autumn 2006

Due to the two half shells an installation without vacuum break is possible!

Existing SIS18 DCCT with added new core

Details


BIW `06, May 1st 2006

BPM development - detector (a)BPM development - detector (a)

Curved section of SIS100

Straight section of SIS100


BIW `06, May 1st 2006

Apertures/mm:

horizontal = 268

vertical = 116

length = 350

separation rings on the ground potential

simulated beam

BPM development – detector (b)BPM development – detector (b)

Different types of BPMs are necessary:

• SIS100 version: elliptical, cryogenic

• SIS300 version: round, cryogenic

• Storage rings: large aperture up to 300 mm, normal temperature env., but high bakeout temperaturesPosition sensitivity and linearity:

For shoe-box type calculated

Δx(f) = K(f) * Δ/Σ+ offset(f)

Careful mechanical design

(high f by bunch-compression)

R&D: Matching RF- and cyrogenic requirements

Starting point: ESR BPM

Necessity of guard rings (1)


BIW `06, May 1st 2006

BPM development – detector (c)BPM development – detector (c)

Necessity of guard rings (2)

Cross talk between plates in one plane (should be low!)

Simulations on ESR type:Geometry Structure on ceramics

Metal plates

no guard ring 1mm gap

-5.1dB -7.9dB

no guard ring 2mm gap

-8.1dB -10.8dB

with guard ring -20.8dB -22.5dB

separation rings on the ground potential

Metal plates seem to be the better choice, but:

Mechanical stability of an arrangement of numerous single metal plates is poor due to experience from collaborators in Dubna (Nuclotron)!

Structure on ceramics chosen!


BIW `06, May 1st 2006

BPM development – detector (d)BPM development – detector (d)

Present layout of SIS100 BPM version

(elliptical shape)

BPM parameters:

Capacity: ~ 100 pF

Length: 30 cm

For maximal beam current i.e. Nz 4x1013 e/bunch and bunch length of 25 ns:

Qm=4.3 x 10-7 C

U=4.3 kV

For minimal beam current i.e. Nz 4x108 e/bunch and bunch length of 60 ns:

Qm=4.4 x 10-13 C

U=4.4 mV

Barrier bucket behaviour (long bunches!) not studied until now!

Further adjustment of parameters needed!


BIW `06, May 1st 2006

BPM development – analog electronics (e)BPM development – analog electronics (e)

In the case of SIS100/300 the hybrid must most likely positioned in the cryogenic area!

From CS

J. Belleman

(from CERN-PS)


BIW `06, May 1st 2006

BPM – data acquisition and analysis (f)BPM – data acquisition and analysis (f)

Behind the amplifier chain no additional analog signal treating direct digitization!

Common EU-FP6-initiative of GSI, CERN and Instrumentation Technologies for a digital data evaluation platform for fast cycling hadron machines with varying frequencies:

Main board 4 channel ADC input board

Scheme of Libera electronics


BIW `06, May 1st 2006

BPM development – data acquisition and analysis (g)

BPM development – data acquisition and analysis (g)

Two different approaches for data evaluation are under development now:

CERN: digital version of classical base line restoring and PLL implementation using RF frequency input and phase tables

GSI: Free running algorithm with the following implementation:

PU signal

Libera

ADC Averaging for noise reduction, using a median filter with a short length of 5

taps

Summing of each data sample at the input -> gate

construction using the fact that the data between 2 bunches should have a linear trend

FPGA

Integration over each

bunch using the

constructed gates

SBC

Position calculation outside the

FPGA due to floating point

limitation


BIW `06, May 1st 2006

BPM development – data acquisition and analysis (h)

BPM development – data acquisition and analysis (h)

Results of offline implementation/calculation:

Both methods (CERN/GSI) are under development and implementation in FPGA code; test are foreseen in the 2nd half of 2006 !

Measurement in SIS18 harmonic number = 4


BIW `06, May 1st 2006

RGM Development – Requirements (a)RGM Development – Requirements (a)

Parameters given by the machines:• Revolution frequency

• in SIS 100/300: 110 – 280 kHz• in the Storage Rings: 125 kHz – 1.4 MHz

• Beam pipe apertures:• in SIS 100/300: 135 * 65 mm2, resp. 90 mm in diameter (SIS300)• in the Storage Rings: up to 300 mm in diameter• adaptive spatial resolution down to 0.1 mm (rel. 1%) necessary due to cooled beams• Transversal measurement range: ~ 100 mm

• Turn-by-turn readout necessary e.g. for matching of the injected beam emittance orientation and dispersion setting with respect to the acceptance• Detection of secondary e-/ions ( conversion with e.g. phosphor P47) , thus

• E-field (E50 V/mm, 1% in-homogeneity) and• B-field for guidance (B0.03 T, 1% in-homogeneity) compact because of limited space

• Read-Out Modes: a) high resolution measurement on ms time scale with CCD camera

b) turn-by-turn: array of ~100 photo-diodes or multi-anode PM or SiPM


BIW `06, May 1st 2006

RGM development – mechanical design (b)RGM development – mechanical design (b)

First design of RGM with magnets, but the following changes are necessary:

• Possibility of change between CCD and multi-diode readout

• Due to low magnetic rigidities in the storage rings compensations of the applied magnetic fields of the RGM are necessary more complex magnet installations

• Alternative design with permanent magnets is under calculation at ITEP, Moscow

First test of RGM version with CCD readout, but without magnetic field are foreseen in collaboration with FZ Jülich at their COSY proton storage ring in the 2nd half of 2006!


BIW `06, May 1st 2006

RGM development – turn-by-turn readout (c)RGM development – turn-by-turn readout (c)

Alternative sensor for turn-by-turn readout: Silicon Photomultiplier (B. DOLGOSHEIN et al., MEPI, Moscow)

First commercial sensor on the market (www.SensL.com)

Up to 103 silicon micro pixels per mm2, dimensions scalable


BIW `06, May 1st 2006

The Most Challenging Part of the FAIR Project ...

The Most Challenging Part of the FAIR Project ...

Realisation/Stage Plan

2007 (start of final design) 2014

Stage 1 Stage 2 Stage 3


BIW `06, May 1st 2006

AcknowledgementAcknowledgement

Instead of a summary:

Thanks to all colleagues and collaborators contributing to

this talk with their papers and pictures!

Thanks to our small technical review board (Tom Shea and

Hermann Schmickler) for valuable discussion and their

consulting!

Thanks for your attention!

Documents

BIW `06, May 1st 2006 Beam Diagnostics Challenges in the FAIR project at GSI The FAIR project - a Facility for Antiproton and Ion Research Planning of