Minutes of the Booster Commissioning Working Group held on 22nd of May 2008

Present: K. Hanke, J. Borburgh, W. Weterings, B. Mikulec.

Agenda:

1. Communications
2. Follow-up of open actions
3. Aperture limitations for H- beam at BI.DIS and BI.SMV
4. Planning of PSB commissioning with Linac4
5. AOB

2. Follow-up of open actions:

• Kicker magnets in LBE line: In order to decide which group is responsible for the kicker magnets in the LBE line, J. Borburgh and W. Weterings requested to know the exact specifications of the magnets.

Assigned to	Start date	Description	State	Result
K.Hanke	2008-05-26	Obtain specifications of kicker magnets in LBE line and send them to W. Weterings.	openclosed	Done.	edit

• Simulations of LBE line: K. Hanke has asked for a fellow to spend some time working on the simulations of the LBE line. OP has asked in total for 2 fellows. The selection committee will take place in May.

3. Aperture limitations for H- beam at BI.DIS and BI.SMV:

Following a presentation of M. Eshraqi on April 10th 2008 (https://twiki.cern.ch/twiki/bin/view/SPL/10April), W. Weterings and J. Borburgh presented the modified design for the distributor and the vertical septum (see 22-05-2008-commisioning.pdf). The aim of this new design is to increase the vertical clearance. The beam parameters from M. Eshraqi were taken as basis for these studies.

The new proposed scheme foresees a beam offset of 6.5 mm instead of 5.2 mm at BI.DIS entrance; BI.DIS should be installed with a vertical offset of -5 mm (inform M. Hourican of this offset). The required parameters for BI.DIS are a max. deflection angle of 5 mrad, max. Bdl of 9.5 mTm, max. voltage of 26.75 kV and max. current of 1100 A. The magnet has already been tested successfully up to 30 kV and 3D field simulations show no saturation for an operation at maximum current. T. Fowler confirmed that the increase in kick of BI.DIS should be feasible.

In this new scheme the strength of BI.DVT40 has to be increased. The feasibility of this has to be checked with T. Zickler and C. DeAlmeida Martins (deflection angle up to 9.2 mrad meaning a change in Bdl by factor of 2.4).

Assigned to	Start date	Description	State	Result
T.Zickler, C.DeAlmeida	2008-05-26	Check if the current BI.DVT equipment is adapted to allow for an increase in deflection angle by a factor 2.4.	openclosed	Has become irrelevant as injection chicane layout has again been changed.	edit

The increased deflection angle of BI.DIS allows to decrease the angles at BI.SMV. This provides additional 4-5 mm clearance at the septum; the min. clearance is now 2.5 mm. This leaves little margins, but seems achievable. Additional beam clearance could be obtained if a bent yoke would be used instead of a segmented yoke (currently 2 segments). This is under study. The yoke gap of BI.SMV amounts to 55 mm.

J. Borburgh mentioned that he is in the process of quantifying the stray field at the septum from simulations. This is required to determine the final thickness of the septum and freeze the design. Once this is done, the beam transport simulations should be readapted to the design changes and if possible should include the influence of these stray fields.

4. Planning of PSB commissioning with Linac4:

K. Hanke presented a first draft of the modified planning. As a first step, the transfer line commissioning period was combined with Linac4 commissioning, with half a year foreseen for Linac4 commissioning and 3 months for transfer line commissioning. It was felt that these 3 months should be reduced to 1 month, also because during transfer line commissioning no access can be given for work on the PSB injection line. The remark was made that transfer line commissioning (with beam to the LBE/LBS lines) can be used as cool-down time to prepare the installation work and should be clearly marked as such in the planning. The ideal timing would be if Linac2 and the Booster would stop at the 1st of December. This would mean that installation work could start beginning of the year. 3 months are estimated as the minimum time required for the installation work in the PSB injection period. PSB commissioning will follow this period.

It seems feasible to advance the KSW installation to the 2011/2012 shutdown and use the KSW as vacuum pipe during 2012 PSB operation. It would also make sense to plan for a MD period in 2012 to already test the KSW.

Maybe the lead distributor could already be removed during the 2011/2012 shutdown. K. Hanke should make sure that this is acceptable and then contact S. de Man to organise the details.

Assigned to	Start date	Description	State	Result
K.Hanke	2008-05-26	Contact S. de Man to organise the removal of the lead distributor for the 2011/2012 shutdown.	openclosed	Will be done during 2009/2010 shutdown (still to be organised).	edit

K. Hanke will include the comments into the new draft planning and send it afterwards to W. Weterings and J. Borburgh for a cross-check. He will then propose the modified planning to the Linac4 core team.

-- BettinaMikulec - 26 May 2008

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