psb finemet upgrade: overview, preliminary results & planning llrf: m. e. angoletta, a. findlay,...

PSB Finemet upgrade:

overview, preliminary results & planning

LLRF: M. E. Angoletta, A. Findlay, M. Jaussi, J. Molendijk, J. Sanchez Quesada (RF/FB, RF/CS)

HLRF: M. Paoluzzi, M. Haase, A. Jones (RF/IS)

PSB simulations: D. Quartullo, S. Albright (RF/BR)

MSWG, 24 April 2015

Outline

1. Project overview

2. 2014 MDs results

3. Plans for 2015 & MD requests

4. Conclusions

5. References

Outline

1. Project overview

2. 2014 MDs results


4. Conclusions

5. References

Why & what 2012 MDs Installations after LS1 Finemet Review Sept 2014

Project overview: why & what

2010: new low-loss Finemet material (FT3L) validated @KEK [4] Aim of the project: to evaluate if it is possible to replace C02

(S7+S10) + C04 (S13) with Finemet-based cavities.

M. E. Angoletta “PSB Finemet upgrade” MSWG 24/04/2015 1

Operation to be assured for 25 more years.

Increased beam intensity (2E13 ppb)

Increased injection + extraction energies

C04 HLRF is limiting system

Upgrade:Linac4 + PSB@2GeV

Wide-band cavities: beam loading compensation needed (fast RF + LLRF feedback)

Each Finemet HLRF (12 cells) used as C02 + C04 Options: 2 straight sections → 16 kV

3 straight sections → 24 kV

PSB HLRF: consolidation [1] + upgrade [2,3] needed

Project overview: 2012 MDs [5]

HLRF [6] : 5-cells installed in Ring 4 (S6), 4 cells (~ 2 kV) for final tests. LLRF: Servoloop on one harmonic (LEIR-based test system.) Operation: acceleration of h=1 beam with C02 + Finemet. Final result: 460 E10 protons (~6A) kept @extraction with 2 kV Finemet.

Problems/limitations: HLRF: Limited total voltage available

Radiation effects on solid-state ampli Limited amplifier diagnostics

Solved during LS1


LLRF: only one harmonic servoed (processing power limitation)

Magnetic fieldFinemet

voltage (2 kV)

BeamC02 voltage (5 kV to 1.5 kV,

non linear scale)

Project overview: installations after LS1

HLRF: 5 additional cells installed in Ring 4 (S6). Now: 10-cells, 7 kV available in total.

LLRF [7] : New DLLRF operational in PSB. Ring 0 DLLRF used for Finemet tests


Project overview: Finemet review (Sept ‘14)

External reviewers: C. Ohmori (KEK), J. M. Brennan (BNL), R. Gaillard (radiation effects consultant)

Strong case for upgrade to Finemet LLRF adequate PSB longitudinal dynamics simulations must be improved

to extrapolate to future beams (intensity, energy)

https://indico.cern.ch/event/315998/overview


Conclusions for PSB:



Outline

1. Project overview2. 2014 MDs results

3. Plans for 2015 & MD requests4. Conclusions5. References

s

Cavity servoloop effectiveness Acceleration with Finemet alone Finemet as C02 Finemet as C04 Finemet as C02+C04 & heating tests 2014 + 2015 simulation

2014 results: cavity servoloop effectiveness [8]

4 servoloops implemented (h=1,2,3,5)

475E10 protons, h=1 beam.

Reduction in detected voltage with/without

cavity servoloop: 30 dB @h1, 20 dB @h2, 20

dB @h3, 10 dB @h5.

No optimisation yet.

Voltage induced by 730E10 protons (h=1 beam, NORMHRS, C02+C04+C16) as measured on h=1..6 by DLLRF.


2014 results: acceleration with Finemet alone [8]

7 kV on Finemet alone (no ferrite cavities ON)

650E10 protons accelerated.

Phase loop closed on Finemet gap return.

Instabilities @ end acceleration, can be cured with C16.


2014 results: Finemet as C02 [8]

Finemet aligned with C02 (frequency-dependent rotation)

7 kV Finemet @h1; 2.4 kV C02; 8 kV C04

~800 E10 protons accelerated on average.

Phase loop closed on C02 gap return.


Signal voltage envelopes during whole cycle.Yellow trace: driving voltage; Green trace: gap return voltage.

Beam @ctime 500. Double-harmonics effects is clearly visible.

2014 results: Finemet as C04 [8]

Finemet aligned with C02 (frequency-dependent rotation), programmable phase for bunch shaping

7 kV Finemet @h2; 8 kV C02; C16 blowup.

~790 E10 protons accelerated on average.


Beam @ctime 768 (before synchro)

824E10 protons

2014 results: Finemet as C02+C04 & heating tests [8]

Finemet aligned with C02 (frequency-dependent rotation), harmonic 2 programmable phase for bunch shaping

3.5 kV Finemet @h1, 3.5 kV Finemet @h2; 4.5 kV C02; 4.5 kV C04; C16 blowup.

~800E10 protons accelerated.

For ~1 hour Finemet MD cycles added to supercycle: duty cycle from 8% (3 out of 38) to 68% (26 out of 38).

VRF151 case must remain < 90 degrees and it’s OK also extrapolating to 100% duty cycle.

Amplifiers heating tests


2014 (+ 2015) results: simulations

BLOnD: Beam LOngitudinal Dynamics

simulation code (under development): treats

multiple RF systems, intensity/energy

effects, acceleration, multibunch…

Aim: to simulate longitudinal stability thresholds with/without Finemet,

for higher beam intensity and for higher energies than those now

available in the PSB.

Simulations presented @ Finemet review in Sept 2014 were limited (no

phase loop, injection and extraction simulated with no ramp).

In 2015 the code has evolved [9, 10] and is now able to simulate quite

realistically the PSB longitudinal dynamics.

Already one MD of data taking (Ring 3) in March 2015 [11].


Outline

1. Project overview

2. 2014 MDs results


4. Conclusions

5. References

Plans for 2015 Questions to be answered Summary of MDs requirements

Plans for 2015

Finemet program to be completed by mid-Sept 2015.

Final Finemet review will take place on Sept 14, 2015.

BE management to take decision on Finemet upgrade by Dec ‘15.

Is the system reliable

Can the system handle high intensity beams

Is the longitudinal impedance compatible with future PSB intensity

& energy

Answers needed to decide on Finemet upgrade:


Plans for 2015 – reliability validation

Question: is the system reliable?

Reliability run with Isolde-type user by using DLLRF Ring 0 + Finemet as C02+C04.

How we will get the answer:

Parallel MDs to setup the beam & normal operation for reliability run. In case of problems, operators will revert to standard operation with Ring 4

DLLRF (no Finemet operation, only ferrite HLRF) via software switch. Aim: to have the beam ready by next Thursday & start reliability run in May.

Not an easy task:

Dedicated MD operating the Finemet HLRF on all users (½ to 1 day).

2014 Finemet cycle settings deleted – had to be recovered from IT database. Changes in driving chain require new loops and rotation settings Problems in updated firmware solved this week.


Plans for 2015 – high intensity validation

Question: can the system handle high intensity beams?


Parallel MDs with very high intensity beams & LLRF servoloops at additional harmonic (8 or more).

Aim: from June 2015 onwards.

We need to maximise the intensity (1E13 protons?) & beam loading as much as possible. How? Beam shortening? Something else? Suggestions anyone?


Plans for 2015 – long. impedance validation

Question: is the longitudinal impedance compatible with the

final PSB intensity & energy? (→ inputs for simulations)


Parallel MDs with high intensity beam (Finemet MD “Isolde beam” clone).

Data to acquire: bunch length, beam profiles, distribution in phase space, particle loss diagrams, Oasis signals…

Switch between Finemet / no Finemet operation.

Alternation between data acquisition and offline data processing + simulation to compare the two. Possibly only up to 1 MD slot / week needed.

Training (Simon) on data acquisition required beforehand.


Plans for 2015 – summary of MD requirements

Parallel MDS:

3 x ½ days per week until mid September.

Possibly more MDs afterwards (until December?) to answer additional

questions from reviewers/management.

Dedicated MD:

Between ½ day and 1 day when possible in June/July.

NB: Strong engagement from RF group. Sizeable amount of

manpower required for development, studies and MDs support.


Conclusions & outlook

Finemet (FT3L)-based HLRF: viable alternative to ferrite C02 + C04 HLRF systems for PSB.

Successful tests in 2012 highlighted weakness/desired improvements that now are removed/obtained. HLRF + LLRF installation done during LS1 allows Finemet operation close to final situation.

Finemet review in Sept ‘14 positive on Finemet@PSB project.

Aggressive MD plan for 2015: LLRF operation, HLRF tests and simulation development. Critical path as it competes with other projects for manpower.

Finemet review in Sept ‘15 + management decision by end 2015.


Finemet @ PSB: very high priority for and strong engagement (manpower) by the RF group.

We ask MSWG to support us with our MD requests.

References

S. Baird, “Keeping The Present LHC Injector Complex Running for 25 Years”, Chamonix 2010.

R. Garoby et al., “Upgrade Plans for the LHC Injector Complex”, IPAC2012, New Orleans, Louisiana, USA, 2012, p. 1010.

K. Hanke et al., ”Status and Plans for the Upgrade of the CERN PS Booster”, IPAC2015, Richmond, USA, 2015.

C. Ohmori et al., “Developments of Magnetic Alloy Cores With Higher Impedance for J-PARK Upgrade”, IPAC2010, Kyoto, Japan, 2010, p. 3711.

M. M. Paoluzzi et al., “Beam Tests and Plans for the CERN PS Booster Wideband RF System Prototype”, IPAC2013, Shanghai, China, 2013, p 2660.

M.M. Paoluzzi et al., “Studies on a Wideband, Solid-State Driven RF System for the CERN PS Booster”, IPAC2012, New Orleans, Louisiana, USA, 2012, p. 3749.

M. E. Angoletta et al., “A Leading-edge Hardware Family for Diagnostics Applications and Low-Level RF in CERN’s ELENA Ring”, IBIC2013, Oxford, UK, 2013, p. 575.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

References – cont’d

M. M. Paoluzzi et al., “Beam Tests Using a Wide Band RF System Prototype in the CERN PS Booster”, IPAC2015, Richmond, USA, 2015.

D. Quartullo et al., “Longitudinal Spac-Charge Simulations with BLONG at Injection in the CERN’s PS Booster”, talk presented at the EuCard/Xbeams Workshops on space Charge, Oxford, 24 March 2015.

V. Forte et al., “Longitudinal Injection Schemes for the CERN PS Booster at 10 MeV Including Space Charge Effects”, IPAC2015, Richmond, USA, 2015, MOPH231.

S. Albright, D. Quartullo et al., “RF Measurements in the PSB Ring 3 for LHC25ns beams”, BE/RF MD note under publication.

[8]

[9]

[10]

[11]

psb finemet upgrade: overview, preliminary results & planning llrf: m. e. angoletta, a. findlay,...

Documents

kv finemet

finemet hlrf

c02 finemet

finemet tests

finemet alonefinemet

finemet gap

finemetbased cavities

linac4 psb