psb dump: proposal of a new design

PSB dump: proposal of a new design

EN – STI technical meeting on Booster

dumps Friday 11 May 2012BE Auditorium PrevessinAlba SARRIÓ MARTÍNEZ

OUTLINE

•Introduction•Constraints and design choices•Proposal of a new design•Analyses•Conclusions

INTRODUCTION• The PSB dump was designed in the 1960’s to cope

with beam energies reaching 800 MeV and intensities of 1013 protons per pulse.

• Over the past years, the dump encountered some problems, i.e. vacuum and water leaks.

• Beam energy and intensity have been periodically increased during the last upgrades.

• A new upgrade in beam energy (2 GeV) and beam intensity (1014 particles per pulse) is foreseen for the near future.

• Consequently: a new dump is needed to cope with this last upgrade.

CONSTRAINTS•Installation and

lifetime•Location •Reliability•Access •Loading•Cooling circuit•Material

DESIGN CHOICES

LS1, LHC’s lifetime. The dump needs to be ready to be installed by August 2013

CONSTRAINTS•Installation and lifetime•Location •Reliability•Access •Loading•Cooling circuit•Material

x

x

CONSTRAINTS

•Location: dimension limitations and integration where the old dump is at present.

DESIGN CHOICES

CONSTRAINTS

•Reliability: minimise any risk of failure (avoid encountering the same problems than in the past)

DESIGN CHOICES

® The design has to be as simple as possible (to maximise reliability, to reduce assembly difficulties and to ease manufacturing complexity).® Not to work under vacuum.® Mechanical connections are preferred over welding.

CONSTRAINTS• Access: the dump core couldn’t be accessed

without a major interruption in the beam availability® no in-situ maintenance can be done® redundancies must be foreseen

DESIGN CHOICES

CONSTRAINTS

•Loading

Parameter Unit Current BeamUpgraded

Beam

Extraction energy E0 GeV 1.4 2

Peak current I* mA 3088.2 9650.6

Average Beam Power W=E0*I kW 6 26.7

1 Max. Beam Size H x V cm 1.64 x 5.61 1.46 x 5.16

1 Min. Beam Size H x V cm 0.42 x 0.81 0.37 x 0.71

CONSTRAINTS

•Loading

DESIGN CHOICES

® Cooling is needed to extract the almost 27 kW of average power of the future beam.® A 2 GeV proton beam requires a dump 130 cm long (when entirely made of Copper).® The diameter is defined to intercept up to 5 of the upgraded maximum beam: = 50 cm

CONSTRAINTS• Cooling circuit: cooling is needed to extract the

almost 27 kW of average power of the future beam▫Cooling by natural convection has been proved to be

not sufficient (preliminary analyses).▫A solution with forced air cooling is not possible

either: impossibility of having a closed air loop with enough flow in this particular area of the tunnel.

▫Water cooling is mandatory to extract the almost 27 kW of average power of the future beam.

▫The minimum cooling flow is estimated at ~2m3/h, when water at ambient temperature is used.

CONSTRAINTS

•Cooling circuit: cooling is needed to extract the almost 27 kW of average power of the future beam® Position of the cooling pipes: close to the beam axis (maximum peak of temperature), provided that radioactive activation of water is kept within acceptable limits. ® Redundancies to improve cooling reliability: 4 independent water circuits

DESIGN CHOICES

CONSTRAINTS

•Material:▫Does not need inert atmosphere.▫Good thermal and mechanical properties, to

optimise heat extraction and to guarantee the structural behaviour of the material.

▫Materials that have a good long term performance in a radioactive environment.

▫Galvanic corrosion in between materials.▫Erosion corrosion in pipes (max. speed of

water).

CONSTRAINTS

•Choice of material: following the principle of reliability and simplicity

DESIGN CHOICES

® Basic metal compounds Thermal and mechanical properties are well known Workability and behaviour in extreme conditions

(such as ionizing radiation) is well assessed® Candidate materials: Graphite, Aluminium, Stainless Steel, Copper, Titanium

PROPOSAL OF A NEW DESIGN

•Geometry▫Multiple-disk like geometry:

To lower the stress level To allow natural air cooling and thermal

radiation to play a role in the heat extraction from the dump

Aluminium keeps levels of energy deposited by the impinging beam low, while Copper helps to release the heat generated in the inner core and acts also as a shielding.

Cylindrical object, two meter long and 50 cm across, with two distinct parts, one meter long each.

Inner core. Disks made of

Aluminium

Outer core, made of Copper

or Stainless Steel

Structure made entirely in Copper or

Stainless Steel4 independent water circuits cool down only the first part


Elastic clamping. Regulates the stress in

the water pipes


ANALYSES*

to be confirmed by FLUKA

- Sliced core made of Aluminium, surrounded by sliced Copper parts.

- Steady State Temp reached in the core: 125°C (water cooling)

- Temp in the Cu part (surrounding the Al core): remains at 22°C

- Max temp in the external surface of the Al disks ~100°C

- Max temp in the external surface of the Al disks ~100°C

ANALYSES*

to be confirmed by FLUKA

ANALYSES

GeometryWater

CoolingAir Cooling E escaping

Aluminium core + Copper safe risky 30%

Graphite core + Copper safe not safe 63%

Copper core + Copper safe not safe 48%

Titanium core + Copper not safe -

GeometryWater

CoolingE escaping

Latest proposal (Al + SS) safe 21%

Latest proposal (Al + Cu) safe 20 %

ANALYSES

CONCLUSIONS

•The design proposed is the result of various iterations

•Considerable number of constraints addressed in the new design▫Placement, logistics▫Material and cooling▫Reliability

•Future design more robust▫Higher energies absorbed and dissipated▫Disruption kept to a minimum

THANK YOU FOR YOUR ATTENTIONQ & A

GALVANIC POTENTIALS

OLD PSB DUMP


Sliced core made of Aluminium, slices 4.5 cm thick, with a 5 mm gap in between them


Aluminium disks, 360 mm , 45 mm thick, 5 mm gap

Sliced Copper parts, surrounding the disks in Aluminium. 250 mm thick, outer 500 mm, inner 360 mm

psb dump: proposal of a new design

Documents

beam energy

beam intensity

beam availability

beam energies

new dump

average beam power w

gev proton beam

average power