IMP Cryomodule Assembly and Alignment Hao Guo LINAC Department Institute of Modern Physics Good morning, everyone! I will introduce the strings assembly of superconductor cavity.

Cryomodule components-CM6 6 HWR, 6 tuner, 6 coupler, 6 SC solenoid, 5 BPM. Thermal radiation shield Aluminum plate and Muti-layer insulation 80K LN2 cooling insulating vacuum: 10-4Pa Clean room assembly - dimension: 4.2m×1.2m×1.6m - beamline vacuum: 10-7Pa 11/28/2018 IMP

Fixture for strings assembly This is the second vision of strings fixture. The main advantage of this fixture is that it could be divided into six parts. Each parts could support on cavity, on solenoid and one coupler. The second vision of CM6 strings fixture. This fixture could be divided into six parts, and each parts could support one cavity, one solenoid and one coupler.

Fixture for strings assembly The second vision of CM6 strings fixture

Assembly environment Class 100 clean room Length: 6m Width: 3m Width of the door: 2m Assembly operators: 4 persons

Assembly procedure Put parts on assembly fixture Blow screws, bolts, nuts, washer , gasket or flange with high purity nitrogen Tight all screws to 30Nm Pre-alignment Connect parts by bolts without fastening This is our assembly procedure. First we put the parts on assembly fixture, than blow the fasteners by nitrogen. After that we adjust the position of the parts, remove plastic film and connect parts. At last we tight all bolts and screws to 30Nm

The counter of particles less than 40 per minutes Assembly procedure The final test of every assemblies without SC cavities before strings assembly Leak check cleanliness Less than 5E-10mbarL/s The counter of particles less than 40 per minutes Before the strings assembly, we had a final test of every parts about leak check and cleanliness.

Challenges for cleaning RF components Welded bellows: the particles will hide in bellows and hard to remove. BPM: the particles will hide in buttons and hard to remove. (assembled and calibration in unclean room) couplers: the particles will hide inside and hard to remove. (Power condition in unclean room) The particle counter of bellows and BPM cleaned by ultrasonic (0.3μm) bellows BPM coupler >300 per 10s >10000per 10s >400 per 10s The main change of structure, we add a needle bearing to let the solenoid could sliding at a certain range. It could let us assemble easier between cavity and solenoid and it easier to protect the cleanliness.

Challenges for cleaning RF components Test area Solution: assembled in cleanroom and cleaned by HPR Parameter of HPR and particle counter (0.3μm) parts bellows BPM Coupler Pressure 60bar 40bar Rotate speed 20rpm Rinsing time 8min 15min 22min for outer conductor, 5min for inner conductor Without clean >12000 per 10s Ultrasonic clean >300 per 10s >17000 per 10s >400 per 10 s HPR 0 per 10s >900 per 10s N2 blow area The main change of structure, we add a needle bearing to let the solenoid could sliding at a certain range. It could let us assemble easier between cavity and solenoid and it easier to protect the cleanliness. Particle counter of BPM after ultrasonic cleaning and drying

Improvement for cleaning RF components We have done already HPR for bellows HPR for solenoids We plan to do The main change of structure, we add a needle bearing to let the solenoid could sliding at a certain range. It could let us assemble easier between cavity and solenoid and it easier to protect the cleanliness. HPR for BPM HPR for coupler

Pre-alignment in cleanroom The purpose of pre-alignment in cleanroom To prevent the abnormal twist of bellow in the cryomodule assembly. At this I will show the sequence of strings assembly. At first step, we join every cavity, solenoid and coupler. Then we adjust level of cavity and solenoid. At last, we tight bolts.

Fixture for strings assembly The detail structure of solenoids supporter Needle bearing The main change of structure, we add a needle bearing to let the solenoid could sliding at a certain range. It could let us assemble easier between cavity and solenoid and it easier to protect the cleanliness. 功能描述 The solenoid supporters could adjust the position of solenoid.

Pre-alignment in cleanroom First step: join the flanges of cavity and solenoid then fix screws without fastening. Second step: adjust levelness of cavity and solenoid by frame level meter. Third step: fasten screws to 30Nm At this I will show the sequence of strings assembly. At first step, we join every cavity, solenoid and coupler. Then we adjust level of cavity and solenoid. At last, we tight bolts.

The improvement for strings assembly All parts could slide on linear guide The structure of supporter have be designed to adjust parts easier. 12 bolts could be used for adjusting the position of every parts. The main change of structure, we add a needle bearing to let the solenoid could sliding at a certain range. It could let us assemble easier between cavity and solenoid and it easier to protect the cleanliness. 功能描述

Low speed vacuum The vacuum pumping rate is limited by mass flowmeter. The rate is 0.1 slm. Mass flow meter for vacuum pumping Mass flow meter for venting N2 The last step, we vacuum the strings and the vacuum pumping rate is limited by mass flowmeter. The rate is 0.1 standard liter per minutes. For our strings, we need 30 hours for vacuum. I had a questions about vacuum leak. If we found the strings is leak, how to solve it? Is that necessary to disassemble all the parts, clean and assemble again. Question: If the vacuum of strings leak, how to solve it?

Alignment process chart Single component’s calibration Bundle calibration BPM+Solenoid Location and measurement of offline network Offline alignment and monitoring Online alignment

Offline alignment and monitoring Portable CMM and Laser Tracker are cooperative used The least alignment time only used laser tracker is about 1-2 weeks; The cooperative alignment time is reduced to 1-2 days

Displacement and deformation of 78K Transverse Vertical Measure range±1.2mm

summary TCM6 passed the beam of 4mA 5Mev CW. So the entire process of cryomodule process is feasible. But the detail should been improved. The improved cleaning process of BPM and coupler could been testing on next cryomodule. The measure range of offline alignment is ±1.2mm.

Thanks for your attention!