Minutes of the LIS Section meeting held on 11 February 2013

Present: Androula Alekou, Fanouria Antoniou, Gianluigi Arduini, Christian Carli, Vincenzo Forte, Adriano Garonna, Simone Gilardoni, Alexander Huschauer, Meghan McAteer, Tatiana Rijoff, Guido Sterbini, Adrian Ulsroed, Letizia Ventura, Raymond Wasef

General Information (Gianluigi)

Gianluigi discussed the proposed group structure to be implemented by the middle of the year and aimed at building sections around areas of expertise. Feedback to Gianluigi and/or to Oliver is more than welcome.

A joint HL-LHC/LIU workshop will take place in September/October with the aim of reviewing the various steps of the upgrade plans and evaluate their impact in integrated luminosity.

The Second meeting of the European Strategy Group for Particle Physics has taken place at the end of January in Erice. The results of the work of the Strategy Group will be presented in Bruxelles in occasion of an EU ministerial meeting in May.

LHC operation with protons against ions has ended on Sunday 10/2 at 6 AM. The target integrated luminosity of 30 nb^-1 has been exceeded in all the experiments. Setting-up for an high intensity run at intermediate energy (1.38 TeV) has started.

Round Table (all)

PS (Alexander, Guido, Letizia, Raymond and Simone):

Measurements of the damping time provided by the transverse feedback at injection as a function of the machine settings (e.g. chromaticity and coupling) have been made confirming the expectations.

Resonance compensation with skew sextupoles. A tune scan has been performed and showed the effectiveness of the pre-calculated resonance compensation settings applied on four independent skew sextupoles to reduce losses when the working point is close to the 3Qy=19 and 2Qx+Qy=19 resonances. For the moment no setting has been tested for compensating both resonances. This will be done in the next days. Tests at lower (than 1.4 GeV) energy will be performed by decelerating the beam with the aim of gaining more margin in the strength of the correctors.

Letizia has started simulations of the longitudinal coupled bunch instabilities expected in the PS according to the impedance model updated last year by Mauro Migliorati. The programme developed by Mauro for Daphne has been used so far.

Hybrid MTE: Losses are observed when the QKE is pulsed. Tune and chromaticity are compensated during the QKE pulse and the reason for the losses is not clear.

The extension of the LHC run might determine some delays in the work planned for the Goward road.

ELENA (Christian, Tatiana)

Christian is evaluating the need to start the work on the transfer line between AD and ELENA already during LS1. This would require modifications of the transfer line between AD and the AD experimental areas.

Subjects being addressed: compensation solenoids for the electron cooler solenoid, instrumentation for the measurement of the electron beam position.

SPS (Adrian)

Measurement of the TT2/TT10 optics (dispersion and betatron mismatch) have been performed with the old extraction bump settings. Data have been taken with the 4 OTR screens in TT2. Analysis of the data ongoing. The dispersion data are consistent among them after introduction of appropriate calibration factors for the beam position monitors in TT2/TT10/SPS.

PSB (Meghan, Vincenzo)

Multi-turn trajectory measurements have been performed with the transverse feedback used as an exciter. Attempts have been done to use the transverse damper as an AC dipole but did not succeed yet.

A tune scan has been performed at the PS Booster. There is a clear difference depending on the direction from where resonances are traversed. This could be due to the asymmetry of  the necktie due to space charge. Different settings for the sextupoles and skew sextupoles correctors have been applied and the effect on losses observed. A reduction of the orbit distortion when approaching the integer has been obtained by correcting the orbit. The correctors used could give an indication of the localization of errors in the machine. It would be good to compare the orbit data with the alignment data. A complete realignment of the PS Booster is planned during the long shut down.

Neutrino studies (Androula, Fanouria)

The issue with the interpretation of the data of the extraction orbit in the SPS with a discrepancy between model and data has been understood (MADX feature).

Preparations for the LAGUNA meeting at DESY (25-27/2 are ongoing) A first version of the high power PS will be presented. A first version of the lattice is available and the specifications for the magnets for a 50 and a 75 GeV options are ready. Collimation studies (with a similar approach to that used for the PS2) will follow.

IBS and SPS studies (Fanouria)

Fanouria is continuing the studies to quantify IBS and Touschek effects in the SPS with LHC ion beams. Examples for the SPS for the IBS MADX module are being prepared and will be included in the next MADX version.

LEIR for Radiobiology (Adriano)

The reason of the strong deformation of the separatrices observed for the slow-extraction has been understood: the sextupoles used for the slow extraction had a small phase advance separation requiring strong excitation in one of them to change the orientation of the separatrix in phase space. Another configuration is being considered.

Monday, 18^th March 2013 at 14:00 in room 6-R-018

Agenda:

General information (Gianluigi)

Round Table (all)

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