Status of the Diamond Light Source ESLS XXII Workshop Grenoble, 25 November 2014 R. Bartolini...

Status of the Diamond Light Source

ESLS XXII WorkshopGrenoble, 25 November 2014

R. Bartolini

Diamond Light Sourceand

John Adams Institute, University of Oxford

OutlineOutline

Operation statistics

The “10 years vision” exercise

Conclusions


Operation statisticsOperation statistics


MTBF target of 72 h still elusive

courtesy V. Kempson

Operation statistics - 2014Operation statistics - 2014


Summary stats for 2014 to date with run 5 yet to finish

Run Custom - 01/01/2014 To 14/11/2014.User Beam Data including beamline start up.

Run Hours: 4359 Total Beam Trips: 89 Run Uptime (%) 90.8%Unscheduled Downtime /Hrs: 398.70Scheduled Downtime /Hrs: 3.38MTBF /Hrs: 48.98Total Beam Delay Faults: 19Total Other Faults: 227MTTR /Hrs: 4.48

courtesy V. Kempson

Operation statistics - 2014Operation statistics - 2014


2nd September: Helium leak in RF cavity 2 forced a quick cavity swap (with the spare brand new cavity – yet to be conditioned).

Cancelled two weeks of users time 9-22 SeptemberRetrieved some uptime by starting earlier in November run (at 230

mA)courtesy V. Kempson

Trips statisticsTrips statistics


Trips dominated by the SC RF

courtesy V. Kempson

RF trips statisticsRF trips statistics


We took the following remedial actions:

Probe blip:added a filter at circuit board level after the LLRF comparator to smooth out the blips

IOT connection:checked all connections on IOTs (fault was in the connections on the delivered assembly)

Vacuum trips:continuing with warm-ups and conditioning

Drive amp chain:dispersed all parts of the faulty chain amongst the different systems

ISC:started high power RF conditioning rather than DC conditioning.

Focus coil:checked isolation of all coils and reworked suspicious radiation shielding

IOT LLRF:changed closed-loop LLRF gain to reduce noise and reset interlock levels to allow 7-IOT operation (still not completely tested)

Filament current:

Quench detector:swapped out the quench detector unit with the spare

courtesy C. Christou

… … and now looking at installing a NC RFand now looking at installing a NC RF


• the loss of two weeks at the start of the last run went down badly, particularly with industrial users;

• general reliability of superconducting cavities has been brought into question- cavity failure is a catastrophic event putting Diamond out of action for several weeks- commonly accepted lifetime to failure of cavities is around 6 years- repair of cavity can be very slow (CLS cavity has taken 2 years)

• normal conducting cavities have been considered as an option for some time- at the moment we envisage adding normal conducting cavities, not replacing superconducting cavities- normal conducting cavities will bring their own problems- removal of common modes of failure

• board meeting resolved to add copper cavities sooner rather than later“the Board didn’t just approve the plan, but instructed us to go ahead”


e.g. EU HOM damped cavitye.g. EU HOM damped cavity



• international collaboration, BESSY, ESRF, ALBA, …• coupler, tuner and HOMs mounted radially• requires external pumping

Hybrid RF straight sectionHybrid RF straight section



Install pair of EU cavities in the RF straight in place of the third SC cavityTwo new cavities can be powered by existing amplifier

No new breakthroughs into storage ringCavities protected by small-bore sector valve

10 years vision10 years vision


25-th April – Science away day9-th June – Science away dayDraft document on 10 Years Vision – October 20145-th November: presented and discussed at the SAC

10 years vision10 years vision

Science driven (7 key scientific areas: biomaterials, chemistry, condensed matter, earth science, integrated structure biology, heritage, soft condensed matter)

• beamline development (optics, detectors, stability, …)

Machine development

• reliability • stability

Source development

• CPMUs (in house)• DDBA• Conceptual design for Diamond II

bid within next CSR – 2016; first beam >2020

Consolidate operation with low V emittance 8 pmConsolidate operation with low V emittance 8 pm


Diamond operates with a very good control of the beam optics • Optics deviation (beta-beating) redecue to 1% level• Emittance [2.78 - 2.74] (2.75) nm• Energy spread [1.1e-3 - 1.0-e3] (1.0e-3)• Emittance coupling ~0.08% achieved → vertical emittance ~ 2.0 pm

6 m rms vertical

Transparent realignment of the machine to easy operation at low coupling (see M. Apollonio’s talk)

Diamond is currently running at reduced coupling 0.3% (8pm V) for users

stabilitystability

One beamline has been given control of the electron beam with a window of 20 um H and V to adjust for long term beam movement and static alignment

courtesy G. Rehm

Now coupling electron beam stability and photon beam stability at sample

Feedback on beamline component not obvious (mirrors 1.4 m long)Electron beam “easier” to move for small high frequencies variations

Motion relative to the beam size

IDsIDs


Seven planned CPMU + SCU development with ASTeC and RAL TD

courtesy J. Schouten

• New cooling system (already under development)

• In situ shimming (wish list) which will require a bench to measure both warm and cold

• develop cold measuring bench (use experience from Bessy, ESRF)

DDBADDBA


Modifying one straight section to add an ID – DDBA cell24 DDBA cell provide a 270pm emittance

Insertion Device

existing DBA cell

modified DDBA cell

BM beamline

ID beamline

Magnets, vessel , BPM buttons contract placednow progressing reasonably well towards their FDR

First magnet due by April 2015 – installation 8 weeks SD in August 2016Beam back November 2016 (one week AP commissioning time)

Status (magnets)Status (magnets)

3.4m mid-cell straight

55 T/m 25 cm

65 T/m 25 cm

-14.4 T/m 67 cm

-14.4 T/m 97 cm

55 T/m 25 cm<2000 T/m2

17.5 cm

Challenging designs but no showstoppers !Other projects (e.g. ESRF) have more aggressive requirements

Even if the minimisation of the emittance is not the primary target, the tight control of dispersion and beta functions requires very strong quads

Diamond IIDiamond II


DLS will produce a Conceptual Design report for Diamond II ~2016

Initial studies are based on MBA (modified 4BA or 5BA – 140-270 pm)Making a strong effort to tailor the machine design to the user requirements

customised opticslength of the shutdown is not a settled questions yet…

Most of technological choices and engineering issues are expected to be similar to the single cell DDBA

Possible new are of development (wrt to DDBA)

magnet design – permanent magnet – longitudinal gradientvacuum chamber design and vacuum system (antechamber - NEG)diagnostics for stability (including electron and photons)

(preliminary) SAC feedback(preliminary) SAC feedback

SAC requested a clear assessment of the overall benefit of a low emittance upgrade beamline by beamline

An example: dispersive branch in I20 (WIP)An example: dispersive branch in I20 (WIP)

This beamline requires large horizontal divergence in order to have a large photon energy span at the sampleThe energy range is correlated with the angle of incidence on the polychromatic mirror (dispersive beamline)

Source divergence defined by the slits opening angle in the FE if ID (wiggler) radiation fan has divergence >> than the slit opening angle

Design the straight section with large electron beam divergence + use a wiggler? May prove sufficient…

ConclusionsConclusions


Diamond is continuously striving to provide a reliable and stable source of high brightness X-rays to users

A 10 years vision is being shaped

beamline upgradeoptic, detectors

machine upgradereliabilitystability

source developmentnew IDsDDBAconceptual design for Diamond II

New low emittance lattice by 202x (0 x 1)

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Status of the Diamond Light Source ESLS XXII Workshop Grenoble, 25 November 2014 R. Bartolini...

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