nToF11 beam request (DRAFT)

Here the different modes of beam desired for the nToF11 run in spring 2007 are described. It is not intended to provide a regular beam request.

- The proton beam at PS extraction has a nominal beam momentum of 24 GeV/c, which is the maximum that can be transported on the FTN line.
- PS is running in harmonic 8.
- The maximum nominal intensity is 5*1012 protons per bunch (ppb). A possibility to increase this to 7*1012 ppb will be investigated. The bunch length is 50 ns.
- nToF11 is a single-pulse experiment. Upon request one and only one pulse should be extracted. A delay between two pulses (with modifications) is at least of 30 minutes, if the mercury jet target is present.
For the purpose of beam tuning, the mercury target is not present and typical, permanent cycling can be applied.

bulletsetup and intensity runs
bulletup to four subsequent buckets are filled
bulletthe intensity per bunch can be chosen from 1 to 5 (7) ppb.
bulletpump-probe method
bulletThis needs the possibility to fill the eight buckets of the PS with the four bunches to our discretion. E.g. three bunches in the first three buckets, the position of the fourth bunch varied from pulse to pulse. Also possible to have two initial bunches and two are varied in position.
bulletIn this mode the pulse length is limited to 2ms due to the strength of the kicker modules (see PS extraction kicker modules).
bulletextended pump-probe method - PS multi kick method
bulletIn order to allow to use the PS multi kick mode of the PS extraction system, the requested momentum is temporarily reduced to the maximum possible (?14 GeV/c?) having two kicks available. This would allow to extend the extraction beyond 2ms.
bullet"50Hz-operation" - PS multi batch mode
bulletWith the possibility of reusing the kicker modules after 10 ms at full strength allows to simulate the nominal 50 Hz operation of the neutrino factory.
bulletHalf of the bunches extracted first, followed 20 ms later by the remaining bunches. Nominal four bunches are assumed.
bulletFilling the PS with 8 bunches requires an additional sub-cycle for filling from the PSB, but allows to study the effect of 50 Hz operation at nominal intensity per "pulse".

The possibility of using the continuous-transfer (CT) option for extraction should be discussed as well.

The beam spot at experiment should be rr.m.s=1.2 mm at maximum intensity to achieve nominal power densities. The quadrupole strengths are kept for all intensitites. A range of displacement of +-5mm in both planes is required to study possible misalignment failures.

Contact PS machine: Christian Carli, Simone Gilardoni, Massimo Giovannozzi, S.Hancock, Gianluigi Arduini (MD planning)
Cc: Ilias Efthymiopoulos, Jacques Lettry, Adrian Fabich, Harold Kirk, Kirk McDonald