Installation of TCL4 in IP1 and IP5
Description
TCL (Target collimator Long Physics debris) collimators in IR1 and Ir5 are designed to protect cold magnets in the matching sections from collision debris, whose intensity depends on luminosity. They are only required downstream of the high luminosity insertions IP1/IP5. In the present LHC collimation system it was foreseen to have 1 TCL in front of D2/Q4 cryostat (TCL4, to be installed during LS1) and 1 TCL in front of the Q5 (TCL5, already installed).The TCL4 were estimated to be required only for the design beam energy of 7 TeV.
During LS1 the TCL4 will be installed, the positions are shown below. The TCL5 will remain operational at their present locations.
More details in the ECR (link).
Proposed positions
| Slot name | Distance to IP1 [m] |
|---|---|
| TCL.4R1.B1 | 149.73 |
| TCL.4L1.B2 | -149.73 |
| Slot name | Distance to IP5 [m] |
| TCL.4R5.B1 | 149.73 |
| TCL.4L5.B2 | -149.73 |
Space reservation of TCL6 in IP1 and IP5
Description
It is proposed to prepare the space reservation and infrastructure for a future installation of a TCL type collimator in front of Q6.
Forward physics programs foresee the installation of very-forward detectors downstream of the Q5 magnet whose operation at high intensity puts constraints on the minimim TCL4 and TCL5 gaps. Opening the TCL5 increases the losses in the matching section. In addition, the insertions of movable detectors during the high intensity operation can be itself a source of beam losses that affect the magnets downstream. For example, the operation of TOTEM at 3.5 TeV in 2011 required an increase of BLM thresholds for the Q6 magnet. Alternative layouts that foresee new TCL collimators downstream of Q5 are therefore considered. In particular, it is proposed to prepare the infrastructure for a TCL collimator in front of the Q6, TCL6.
More details in the ECR (link).