Vacuum downstream the plasma exit and upstream of the spectrometer dipole

Friday 19 Sept 2025, 10:00 → 12:00 Europe/Zurich

Participants: Maria-Carmen, Patric, Marlene

Notes from the discussion

• At least two vacuum pumps (placed symmetrically) are required between the plasma exit and the spectrometer dipole: one turbo pump and one ion pump.
  * Vacuum requirements downstream of the plasma are the same as for the proton line: 1e-8 mbar.
  * Keep in mind that Rb vapor acts as a getter pump.
  * To do (Marlene): Clarify whether the quadrupoles come with vacuum pipes and specify the connection flange size (ideally share the CDD code).
  * Consider adding orifices to protect vacuum equipment from Rb contamination.
  * There should be two valves between the plasma exit and the beamline to allow for disconnection.
  * Existing DN40 valves can be reused.
  * MPP/GWA will clean the valves during the first week of October. If VSC equipment should also be cleaned, this can be coordinated.
  * To do (Marlene & Patric): Define beam pipe diameters and identify where equipment will be placed.
  * To do (Maria-Carmen): Provide a list of beamline space requirements for:
    * Bellows (DN40, DN63, DN80)
    * Transitions (DN40–DN63 and DN63–DN80)
    * Turbo and ion pumps
  * At least one bellow is required between rigid systems.
  * Two bellows are required for any system that needs alignment.
  * MPP/GWA will wash some equipment with water; these components can be reused after a mild bakeout at ~150°C.
  * The 3rd expansion volume will also need a vacuum pump; the flange is already included. To do: Clarify the flange type.
  * The 3rd expansion volume will likely include a paddle to shield Rb when the electron beamline is not in use.
  * The upstream expansion volume will likely remain unchanged; the downstream one may be modified if space conflicts arise. An L-shaped structure may be added to better protect the pumps.
  * To do: Arrange a discussion on which signals will be needed from which equipment (e.g. for e-gun protection).

 

 

Follow up email from Maria Carmen on the sizes:

 

Vacuum Item	Comments	Length (mm)	Gaskets gap (mm)	Length to be considered (mm)	CDD	PLM Link
Bellow DN 40		66	0	66	SPSVCW_0062	ST0752759_04 AA.00 Bellow Ø95-Ø95 Ø63/Ø60 L=66 - Profil
Bellow DN 63		76	4	80	SPSVCW__0012	ST0621428 2.02 VC Ø95-Ø95 Ø63/Ø60 L=76 CaV Ø95-Ø95 Ø63/Ø60 L=76
Bellow DN 80		115	4	119	SPSVCW__0018	ST0622995
Transition DN159 to DN63	Includes a bellow	124	4	128	SPSVCW__0017	ST0622860_02 --.02 VC- Ø206-Ø95 Ø63/60 L=124
Pumping tank (turbo pump)		246	4	250	SPSVPW__0005	ST0599394 3.02 VC Ø153-Ø150 - Ø84/80 - L=246 C à V Ø153-Ø150 - Ø84/80 - L=246
Pumping tank (ion pump)	The length includes two welded bellows -> no bellows need to be added around this tank	499	4	503	SPSVPW__0004	ST0587036 2.01 VC- Ø95-Ø95-Ø63/60-L=499

 

DN40 valves need 35 mm on the beamline

 

Backup info:

The magnets we had originally selected are:

• 3x https://norma-db.web.cern.ch/magdesign/idcard/577/
• 1x https://norma-db.web.cern.ch/magdesign/idcard/160/ 

 

potentially new dipole: 

https://norma-db.web.cern.ch/magdesign/idcard/186/#1

10:00 → 10:20 Introduction

Speaker: Marlene Turner (CERN)

intro.pdf