Minutes of the Booster Commissioning Working Group held on 04th of February 2010

Present: O. Aberle, G. Bellodi, A. Dallocchio, C. Carli, R. Chamizo, J. Coupard, K. Hanke, L. Hein, T. Hermanns, M. Jones, R. Maccaferri, B. Mikulec, A. Newborough, D. Nisbet, M. Vretenar and T. Zickler (at end).

Agenda:

1. Communications
2. Follow-up of open actions
3. Quadrupole upgrade proposals for the LBE line (A. Newborough)
4. Work-Packages affected by the Dump/LBE/LBS Lines with Linac4 (T. Hermanns)
5. AOB

1. Communications

The last minutes have been approved.

2. Follow-up of open actions

The follow-ups will be treated in one of the coming meetings.

3. Quadrupole upgrade proposals for the LBE line

A. Newborough presented a few upgrade options for the quadrupoles in the LBE line (see LBE Quadrupole Upgrade). Available magnet families are of type SMIT-Air, SMIT-Water, QTN, QLC and Q#E, but all of them are from the 70s or even older. The 3 latter have conflicting sizes (height and width), and the SMIT-Air would become to hot for the required current.

Therefore the proposal is to keep the SMIT-Air magnets in place, but to modify them to install water cooling. These magnets are also used in the BTP line. As has been discovered there, the coils are not anymore in good condition and should be re-fabricated (2+1 spare set; ~15 kCHF per set). This could be a common project and seen as synergy with the consolidation of the complex. The total cost of the magnet upgrade is estimated to ~50 kCHF excluding manpower; total project duration: ~1.5 years.

The current power supplies (20 A DC) will have to be exchanged. It is not possible to pulse the magnets, but the non-ppm behaviour is considered acceptable for the LBE line measurements.

Concerning the spectrometer magnet in the LBS line, a new design is required. Before the final parameters can be fixed, it is mandatory to know the final length of the line (which is defined by the special dump design at the ceiling). B. Mikulec and T. Hermanns have sent all required beam distributions to the team of R. Chamizo and V. Vlachoudis to allow to pursue the simulations. T. Zickler estimates that the design of the magnet needs to start at latest beginning of 2012.

4. Work-Packages affected by the Dump/LBE/LBS Lines with Linac4

As the simulation studies for the designs of the dump/LBE/LBS lines have been finished, a list of required equipment and measures (installation, commissioning, etc.) for a technical realization have been prepared. The aim of the presentation of T. Hermanns is to alert the different work package holders of the installation/upgrade of the three diagnostic lines so that they can adapt their work packages accordingly (if necessary). In the first part of the presentation the contributions, which are specific for each of the three lines, were summarized, while in the second part the contributions were listed, which are common to all three lines. Per item an assignment to a work-package has been proposed.

Remarks

• WP 2.7: The readout cameras for the fluorescence monitors (dump and LBE lines) must be selected to meet the required measurement resolutions. However, they must be so radiation-hard that they can tolerate the radiation level induced by the activation of the beam dumps. Therefore, the cameras must potentially be particularly shielded.
• WP 2.9.1: The steerer magnet can tolerate a maximum current of 10 A, but it is already driven with 9 A during emittance measurements of 50 MeV Linac2 protons. Given that the momentum is approximately doubled when switching to the Linac4 beam, it can be estimated that the current must be doubled as well to obtain the same correction effect. This is above the tolerable current of the magnet. However, the dedicated power converter can still be used because it can provide up to 20 A.
• WP 2.10: For the dump and LBE lines the power converters are assigned to the quadrupole magnets.
• WP 2.10: The power converter for the LBS line should fit to the spectrometer magnet.

• The slit is one crucial device of the LBS line (small vertical aperture of 1mm but macroscopic length of about 200mm, absorption of 160 MeV Hminus-ions, maybe cooling, etc.). Therefore, a collaboration between WP 2.7 and WP 2.13 is proposed to benefit from mutual experiences and knowledges.

Remarks

• WP 2.11: New vacuum chambers are required for dump and LBS lines. For the LBE line only a refurbishment of the vaccum system starting downstream of the quadrupole magnets is necessary.
• WP 2.12: The synchronisation of the beam with the hardware and the distribution of other control signals is part of the work to be done by the WP "control systems".
• WP 4.2: For the integration it must be investigated how the existing equipment can be lifted and removed from the LBS and LBE line areas (are there rails on the ceiling?).
• WP 4.4: The commissioning of the LBS and LBE lines are connected to the transfer line commissioning, contributions by WP 4.5 cannot be explicitly defined, but are implied as well.
• WP n .def.: For the drawings of the LBE/LBS lines the responsibility must be defined, whereas it seems clear that the integration drawing of the Linac4 dump line can be covered by the section of J.-P. Corso and A. Dallocchio. It should be clarified if a real design drawing or only an intergration plan has to be provided for the LBE and LBS lines. Geometrical contraints due to the planned/existing experimental areas might demand a revision of the proposed equipment designs. Persons to be contacted are J.-P. Corso and A. Dallocchio.

• The LTB.BHZ40 bending magnet (deviates the beam from the transfer lines into the LBE or LBS line) is specified to provide the stronger B-field required for the higher-energetic Linac4 beam () while only are required for Linac4 operation. Its power converter is already considered to be replaced. Nevertheless, it must be verified, if the water flow through the magnet is sufficiently high to cope with the increased cooling requirements.
• The water-cooling circuits for the magnets in the LBE/LBS lines must be considered. At the moment they are connected to the LEIR water station, which operates already at its maximum performance. Further cooling requests (being absolutely necessary when the LBE quadrupoles are changed from air- to water-cooled magnets) could potentially be achieved with this circuit once Linac2 will be disconnected. This option is still to be verified. However, a general revision of the cooling infrastructure could be advisable. As a conncetion of the LBE/LBS-magnets to the LEIR circuit stops the lines from operation during LEIR maintenance work, a decoupling of the two zones including LT and LTB should be considered.

4. AOB

The next meeting is planned to take place on 25th of February 2010 at 14h00.

-- ThomasHermanns - 04-Feb-2010%META:FILEATTACHMENT{name="100204_LBE_Quad_Recommendation.pdf" attachment="100204_LBE_Quad_Recommendation.pdf" attr="" comment="Presentation on options for LBE line quadrupoles" date="1265277950" path="100204_LBE_Quad_Recommendation.pdf" size="2815355" stream="100204_LBE_Quad_Recommendation.pdf" tmpFilename="/usr/tmp/CGItemp43585" user="thomas_2ehermanns_40cern_2ech" version="1"}%%META:FILEATTACHMENT{name="100204_Update_WPs_with_DiagnosticLines.pdf" attachment="100204_Update_WPs_with_DiagnosticLines.pdf" attr="" comment="Presentation on workpackages affected by installation/upgrade of Linac4 dump line and LBE/LBS lines" date="1265277992" path="100204_Update_WPs_with_DiagnosticLines.pdf" size="2894112" stream="100204_Update_WPs_with_DiagnosticLines.pdf" tmpFilename="/usr/tmp/CGItemp48630" user="thomas_2ehermanns_40cern_2ech" version="1"}%