Experience Fabricating the Storage Ring Vacuum Chambers for NSLSII

July 12th, 2011Prepared by: Charles Hetzel

Facility and Cell Overview.

Pumps and Valves.

Instrumentation and Absorbers.

RF bellows.

Chamber Cross Sections and Fabrication.

Chamber Assembly and Production Status.

Vacuum Instrumentation Rack Overview.

1- Accelerator Tunnel

2- Experimental Floor

3 - 200MeV LINAC

4 - Booster (C=158m)

5 - RF Building, liquid He Plant

6 - Service Buildings

1

2

3

4

56

6

6 6

6

Nominal energy: 3GeV

Nominal current: 500mA

30 cells (DBA) in 5 pendants

Ring circumference: 792m

Long straight sectionRF gate valve

S3Dipole

S4Multipole S5

Dipole

S2Multipole

S6Multipole

ID photon extraction

Dipole and 3PWphoton extraction

3 pole wiggler (3PW)

Each section of the cell is composed of girders assemblies. 3 focusing and 2 bending segments (DBA). Alternating long and short straights (9.3m and 6.6m).

Photon extraction takes place at S3 and G6.

The ring is divided into 60 vacuum sections. Sectors can be isolated with RF gate valves. Design pressure (beam on): 10-9 torr.

Fast corrector

Short straight sectionRF gate valve

200 l/s ion pump (8” or 6”)TSP cartridge

Right angle valve

100 l/s ion pumpTSP cartridge

NEG strips (St707)1500m

Turbo pump cart18 units

All metal RF gate valves isolate cells and ID straights. Double position indicators (to vac PLC and to EPS PLC). Radiation resistant and bakeable. Two first articles received. Additional RF gate valves used to isolate SC cavities.

All metal gate valves used in transport lines and font ends.

Right angle valves Rough pumping. Instrumentation isolation.

RF gate valve62 units

All metal gate valve40 units

Right angle valve270 units

Instrumentation located in dipole chambers.

CCG and RGA in S3

CCG and TCG in S5

Gauge tree with isolation valve.

Flange absorber21mm X 64mm

90 units< 200 W (< 16 W/mm2)

Absorbers intercept unused dipole fan radiation.

Intercepting surfaces are made GlidCop Al15.

Stick absorber20mm, 22mm, 25mm

130 units< 700W (< 5 W/mm2)

Glidcop: 130°C, Tube: 119°C

Crotch absorber21mm

60 units< 1800W (< 57 W/mm2)

GlidCop: 180°, Tube: 127°C

Requirements:

Misalignment: +/- 2 mm

Stroke: +10/-15 mm

Angular deviation: +/-10 mrad

Low impedance

RF fingers(GlidCop)

Finger retainer(316L)

Bellows weldment(316L)

Contact springs(Inconel 718)

Sleeve(316L)

Water cooled flange

Storage ring will require ~ 220 units

100 piece order in process

Weldment purchased, assembly @ BNL

Coil spring(Be-Cu)

Multipole cross sectionDipole cross section

Fast corrector sectionS4A cross section

Only 2 vendors were willing and able to produce our extrusion.

180 multipole extrusions.

140 dipole extrusions.

Extrusions were fabricated over ~18 months.

Incoming extrusions were inspected.

Dipole chambers. Bent into shape.

Thermally cycled.

Re-measured.

Packaged and shipped for machining.

Welding of flange-adapter sub assemblies. Out of tolerance flanges.

Sub assemblies to chamber welding.

Bake out and vacuum certification. Leaky flanges (21 flanges, 10 chambers)

Currently producing 10 chambers per month.

Note: Pictures taken at Argonne National Laboratory

Measurement description Target Avg. Measured Values

Absorber flange to beam center 290.6mm 289.0 +/- 1.5mm

Flatness of machined surface +/- 1mm +/- .6mm (1.8mm max)

Flange angle perpendicular to the orbit plane 9 mrad max +/- 3 mrad (7 mrad max)

Transition flange twist 9 mrad max +/-3 mrad (7 mrad max)

Minimum wall thickness in machined area 3mm 2.5mm (1.9mm min)

Measurement description Target Avg. Measured Values

Absorber flange to beam center 252.0mm 251.5 +/- 1.4mm

Chamber flatness near magnet pole cut outs +/- 1mm +/- .56mm (1.4mm max)

Flange angle perpendicular to the orbit plane 9 mrad max +/- 3 mrad (10 mrad max)

Transition flange twist 9 mrad max +/- 5 mrad (6 mrad max)

Exit port survey point X 332.2mm 332.4 +/- 1.5mm

Exit port survey point Y 7.1mm 7.1 +/- .5mm

BPM

rf shield

NEG assembly

Bake out and conditioning Cal rod heater

Currently assembling 10 chambers/month

Removal of surface contamination.

400ppm ozone in oxygen @ 70°C for 6 hours. NEG activation 35 A@120 C. Cool down and reprocess.

Treatment performed on 9 out of 90 chambers.

P = 1.3 x 10-9 Torr3X bake 6 h@120 C.

P = 8.5 x 10-10 Torr

Chamber Ordered Machined Welded Assembled

S2 34 32 (94%) 32 (94%) 30 (88%)

S4 33 18 (54%) 18 (54%) 16 (47%)

S6 34 24 (71%) 12 (35%) 12 (35%)

35 mm Dipoles 62 62 (100%) 36 (58%) 27 (44%)

Totals 163 136 (83%) 98 (60%) 85 (52%)

Install after magnet pre-alignment (100µm).

BPMs positioned using laser tracker (mechanical center).

Adjustment may be required after magnetic alignment (30µm).

Pumps and bake out wiring added after final alignment.

Final leak check and vacuum signoff.

Three racks/cell located on mezzanine IPPS, TSP power supplies Gauge controllers (CCG, Pirani)PLC chassis, MOXA

Cables: Low smoke, zero halogen, tray rated

Computer system w touch screen

Joe Gagliano, George Goeppner (APS)

Vacuum techs

C. Longo

S. Sharma

L. Doom

V. Ravindranath

T. Dilgen

B. Kosciuk

Gao-Yu Hsiung and June-Rong Chen (NSRRC)

Many others in and out of NSLS-II