LIU external beam dump review External beam dump option A: branching off from LSS6
Summary: LIU-SPS external beam dump review
description
Transcript of Summary: LIU-SPS external beam dump review
![Page 1: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/1.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 1
Summary: LIU-SPS external beam dump review
SPS external dump review
![Page 2: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/2.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 2
Scope of workshop and introduction SCHMIDT, Rüdiger
● The SPS has compared to other accelerators a rather high beam power and it is among the most powerful proton accelerators worldwide
● Is motivation clear and sufficient?● Are specifications complete, with enough margin?● Are worst-case beams defined, and repeated dumping for extended periods?● Margins: design is focused on first phase (incl. HL-HC parameters) using known
future beam parameters, what are future upgrade options if parameters will further evolve?
![Page 3: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/3.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 3
SPS beam dumping: from today to LIU eraVerena Kain
● Need to dump all beams, all energies, all types (E, emittance, I, repetition period)● Emergency dump and setting up● Start with relevant beam parameters that are known● Max intensity and cycle length are important parameters● What is the average beam power? This number is most useful to compare different
beams.● New projects: SHIP with 7.2 s cycle length, LAGUNA, …. 320 bunches for LHC, … should
be taken into account … what impact does it have on the current design?● Operation scenario (e.g. waiting time between cycles, after an emergency dump)● Current dump in LSS1, H and V sweep (V is fast), internal beam dump, injection kickers
in same area. Two beam dump blocks, low and high energy, some forbidden zone 28.9GeV-102.2GeV. At 14 GeV high E dump is not sufficient. Bumps are used, depends on optics.
● Dose close to the beam dump: up to 15-25 mSv/hr● 86% of energy is absorbed… where does the rest go?● Graphite is open to beam tube…. issues with vacuum pressure spikes (HW interlock)
![Page 4: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/4.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 4
SPS beam dumping: from today to LIU eraVerena Kain
● Robustness: repetitive dumping is an issue● Limits were 18 shots, 6 s cycle, then wait 5 min (total 408 s, 8.6e14 protons)● Limits were exceeded several times per year, no “formal” limit was set● Damage with current beam parameters can be avoided by operational procedures / SW
interlocks● One shot of LIU standard would go above operational limit (this limit went down from
400 C to 200 C)● What are the limits? One shot, continuous use.● Disadvantages, but in principle ok for beam parameters● HW upgrade…. no dead zones where we cannot dump● Emergency beam dumps in in forbidden zone (only very few dumps, per mille effect)● Improved logging needed ● How much beam / power could one put on the external beam dump?
![Page 5: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/5.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 5
Recently observed problems with present TIDVG,Ivo VICENTE LEITAO
● Issues: prone to water leak, degassing, radioactive in LSS1● During LS1 some refurbishment was done● Al debris found during LS1, Al block damaged, pieces of about 1 cm, clear damage, no
visible impact on beam operation, graphite block ok● Damaged beam dump due to excessive beam load – dumping for extended periods● New TIDVG ready by 31 August● Some improvements have been done, and some improvements will be done in the
future (e.g. temperature sensors)● Maintenance with high accumulated dose: training, robotics, design for end-of-life● Define beam load: what parameters are relevant? ● Are there any other beam dumps or TEDs at CERN in a similar condition? List of dumps,
and list of parameters….. for all dumps and TEDs.● What is the monitoring and recording of data● Upgraded internal beam dump for LHC, for what load? Emergency beam dump?
Operational issues?● What damaged the present beam dump? CNGS very likely above by a factor of two.● Status of old beam dumps TIDVG1?
![Page 6: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/6.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 6
Recently observed problems with present TIDVG,Ivo VICENTE LEITAO
● Outgassing issue for new dump….● Initially “protected” by vacuum (valves close and stop beam due to high pressure)● Damage of upstream part? Nothing seen….● Are different dumps needed?● Emergency and operational beam dump: why have not only one external beam dump?● Fraction of emergency beam dumps / operational beam dumps
![Page 7: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/7.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 7
Rradiation Protection considerations,H. Vincke
● TIDV main problem, about 10e18 p/year, severe radiation problems (activation)● High dose rate, up to 25 mSv/h after 30 h (one meter from equipment), many
consequences● Momentum collimator TIDP is next (3 mSv/h)● Air activation: release close to Bat. 54 – to public close to 10 muSv/y● Air-born radioactivity, tunnel monitors trigger● Both could stop SPS (happened in 2004, and might happen again with beam dump that
is outgassing)● New beam dump should avoid such problems: redesign or external beam dump
(external beam dump more promising option)● External beam dump: LSS1 will become much cleaner: majority of protons should go
out (order of a factor of 10)● New beam dump considerations: prompt dose, activation, air● Prompt dose: shielding – high E muons go far. Annual muon dose , 550 m concrete to
be avoided – not to have a beamline pointing upstream● 10 m concrete should be present to avoid controlled area● Shielding well defined, molasse could be used
![Page 8: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/8.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 8
Rradiation Protection considerations,H. Vincke
● Activation around new beam: no access limitation in the vicinity, concrete shielding of 3 m radius
● Some operational scenarios: 2e18/yr and 2e18/yr + MD -> acceptable, after one day 1-10 uSv/h
● Other scenarios if there is too little space, can be optimised, not yet fine tuning.● Air activation: prevent immediate air release (consider location)● Dose to accelerator equipment: no problem to outside shielded region (cable exchange
not required, say, every 10 years)● What beams can be dumped? How much fraction of the power?● Integrated power is the parameter● Momentum collimator TIDP is next (3 mSv/h): can the dose be brought down? Not
clear, better when operating without transition● Fixed target beam after extraction should be also extracted (few % of beam end of each
cycle)● Transport of an activated dup: needs to be considered, but can be done…
![Page 9: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/9.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 9
Energy deposition considerations for the worst SPS beam scenarios, Genevieve STEELE
● One shot for each beam dump was calculated● Run 2 beam parameters were considered, up to 4e13 protons● Sweeping is considered, different for different beams (depends on batch length), is an
important factor for one shot, emittance is less of an issue – Run 2 dT increase of 70 C ● Run 3: dT increase of 170 C ● Different cores lead to different T● Ti – advantages, optimisation still possible● Increase of high density graphite? C-C? Difficult to get….adding some other material?● For emergency beam dump do not need to stop 80% protons● TEDs: dependence of beam spot size. Even more critical…..higher energy deposition,
but closed. What would happen? Closed system. Risk to be analysed.● What is the impact of melted Aluminum?● TED –could we do some monitoring?● External dump: beta function of = 1000….1800 m assumed● Would be 7 m long if only graphite (dT = 1000 C)
![Page 10: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/10.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 10
Energy deposition considerations for the worst SPS beam scenarios, Genevieve STEELE
● For 4 m, up to 800 C in copper, or up to 450 C with longer graphite part● Longer graphite absorber could do it● Less constraints for any external beam dump● Shock waves – 2nd order problem, also if the material close to melting temperature?● Plastifying – how does it evolve with time?
![Page 11: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/11.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 11
Thermo-mechanical analysis, Florian PASDELOUP
● TIDVG 1 from 2000 to 2004 ● TIDVG 2 from 2006 to 2014● TIDVG 3 from 2014 to 20xx● HL-LHC 4.82 MJ● Cooling system cools copper part, cooling of Al depends on the Thermal Contact
Conductance ● Al is limiting factor, bake-out weakens it: Al at 250 C during 350 h decrease yield
strength by 68 %● dT should not be higher than 150 C● Stress less than 77 MPa, elastic, higher plastic● Between 250 and 600 C, not clear, above there is melting● Plastification can lead to reduced cooling● For 10 pulses, cooling to the outside not important, heat capacity and conductivity of Al
block leads to cooling of Tmax● Plastification happens after a few shots (for new TIDVG)
![Page 12: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/12.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 12
Thermo-mechanical analysis, Florian PASDELOUP
● After 47 pulses, temperature reaches 450 C (assuming nominal cooling, too optimistic)● Ideas: higher density graphite, other material (e.g. boron nitride) ,eliminate Al and use
Ti, improve cooling, …● Cooling of Al absorber blocks possible? Not obvious, problems in the past….● Longer SPS cycles? No real gain….● How many pulses to get to melting point? 47 pulses….● Copper block is cooled, should be not problem….. ● Interesting to understand observed damage mechanisms of Al (not clear how a 1 cm
piece of Al could form)
![Page 13: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/13.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 13
External beam dump option A: branching off from LSS6, Jose ABELLEIRA
● Two options: TT61 and TNC (HiRadMat) tunnels: old neutrino tunnel or using HiRadMat tunnel
● Extraction system can be re-used● Some modification of magnets: 4 MBS (larger aperture) instead of 2MBB● Vertical bending is an issue: option to use existing tunnel, ● No access in HiRadMat when extracting in LSS6● Long shielding for muons, 600 m long shielding● Or have a horizontal beam path, excavation needed, tunnel of 140 m required,
complicated option● Other angle, going through surface. What about molasse? Enough shielding? ● TNC: water activation? Since dump is close to tunnel wall: no issue● Very close to HiRadMat – HiRadMat dump to be moved● Could there be only one dump? For HiRadMat and the external dump. No.● Beam size would be large enough● Issues with interlock – beams with same energy● Cost is in the order of several MCHF
![Page 14: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/14.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 14
External beam dump option A: branching off from LSS6, Jose ABELLEIRA
● Not clear what such external beam dump could● Civil engineering difficult, access difficult● Dipole magnets could dilute muons● Energy and emittance: does beam fit into aperture
![Page 15: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/15.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 15
External beam dump option B: branching off from LSS4,Francesco Maria VELOTTI
● Studies only done for LHC beam types, extend use of such dump going on (e.g. FT 5%)● LSS4 dedicated line● Tunnel enlargement needed● Behind TT40 create a dump line in TI8● MKE.4 could be extended to 21 mus● Two versions studied…. with different dilutions● Aperture has been studied (emittances for slow extracted beams)● CE enlargement is best for CE● Enough space for sweepers● Order of 5 MCHF without CE (incl. sweepers)● What beams can be dumped with what type of systems (Energy, emittance)?● Not clear if FT beams can fit through aperture…. some magnets might be too small● Better to have only one cross section● If we can dump all beams above 150 GeV (LHC), 300 GeV (FT) we would gain a lot,
below is 1 %● Early dumps could be at higher energy, is this preferred? Possibly… ● How to do it operationally – operational scenarios….
![Page 16: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/16.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 16
External beam dump option B: branching off from LSS4,Francesco Maria VELOTTI
● Operational scenarios….to be developed. ● RP prefers TI8, better shielding, muons no problem, air activation better● HiRadMat – ventilation system might have to be considered
![Page 17: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/17.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 17
Civil engineering work, Martin MANFREDI
● LIU-SPS external beam dump in LSS4 was assumed● Path to access with some distance in several tunnels● Several options are being studied● Enlargement 68.5 m * 10.5 m wide or 73 m * 10.5 m or 91 m * 10.5 m (concrete and
iron shielding) or 83.6 m * 12.5 m (only concrete shielding)● Distance between TT41 and new tunnel at least 4.80 m● Molasse could be used for shielding● Exchange of the dump to be discussed, several options● Displacement from TI8 line is fixed● Different options: CE cost between 8.9 and 12.6 MCHF (incl. 10% contingency and
consultants), uncertainty about 50%● 5 years project, CE works could be done during 20 months, some GS resources needed● Reinstallation about 6 months… what about operation of Awake? ● Shielding on the back side needed – not needed, could reduce CE (what about water?),
could be faster
![Page 18: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/18.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 18
Civil engineering work, Martin MANFREDI
● Can we access the area when no extraction in LSS4 – probably yes, to be studied● Shaft PCG8, can it be used? Could be better…● Should start soon (consultant and contractor) – begin of 2015 when activities should be
done in LS2 ● Dedicated extraction line: would it be possible? More kickers, expensive, but would be
of some advantage…still not to be discarded● Extraction kicker in the line… if LHC injection is not permitted, send beam into external
beam dump ● Extra extraction kickers in SPS? The it would be better to build a new system in LSS5.● LSS5: SPS performance (e.g. impedance), use of LSS5 for other applications, cost of new
system, radiation in LSS5, radioactive zone in LSS5
![Page 19: Summary: LIU-SPS external beam dump review](https://reader033.fdocuments.in/reader033/viewer/2022051216/5681500a550346895dbde55b/html5/thumbnails/19.jpg)
CERN
Rüdiger Schmidt Review 30 July 2014 page 19
Summary
● Motivations for an external beam dump: activation, efficiency of operation (HL-LHC)● An external beam dump should be designed to be used for the next, say, 40 years (a
least it should be designed such that an upgrade is possible)● Beam parameters improved over the last 40 years, a similar improvement is expected
for the future● Could one external dump use for all beams?● Logging of parameters to be improved