Beam Line Technical Specifications
- Chris HALL (Unlicensed)
IMBL beams
Our x-ray beam monochromatic energy range range is: 20 keV – 120 keV
Both 'White (polychromatic) and monochromatic beams are available in all enclosures.
Descriptions of the range of source spectra can be found in the IMBL Spectrum section.
IMBL Layout
Beamline layout for the first four hutches (1A - 2B)
A table of distances along the beam line (courtesy: A. Stevenson, MCT beamline)
item | hutch | distance (m) | comments |
|---|---|---|---|
Front-end mask | FE | 7.53 | 6.57mrad (H) x 0.983mrad (V) |
Front-end photon shutter | FE | 8.154 | 49mm (H) x 6.8mm (V) = 6.0mrad x 0.83mrad |
IDT mask | FE | 10.316 | 5.12mrad (H) x 0.325mrad (V) = “5mrad (H) x 0.3mrad (V)” |
Diamond window | FE | 10.559 | 53mm (H) x 3.2mm (V) = 0.6 x 0.05mm (thick) - damaged & removed |
Main gate valve | FE | 13.22 | end of front-end |
In-vacuo vertical primary slits | 1A | 13.7 | water cooled |
In-vacuo horizontal primary slits | 1A | 14.0 | water cooled |
In-vacuo filter vessel | 1A | 14.7 | 5 paddles (at 14.39, 14.53, 14.67, 14.81 & 14.95 m resp.); water cooled |
DCLM | 1A | 16.15 | to middle of tank; see elsewhere for details |
Diagnostic cross | 1A | 17.24 |
|
Photon shutter | 1A | 17.64 |
|
MRT shutter | 1A | 18.20 |
|
Upstream side of 1A/1B wall | 1A | 19.248 |
|
Downstream side of 1A/1B wall | 1B | 19.348 |
|
Be window* | 1B | 20.4 | polished; 0.35mm thick; vacuum upstream & He-flushed (68mm path) downstream; 0.0015” (38um) thick Al foil to air |
Upstream side of 1B/2A wall | 1B | 25.348 |
|
Downstream side of 1B/2A wall | 2A | 25.448 |
|
Be window** | 2A | 30.7 | polished; 0.35mm thick; vacuum upstream & He-flushed (81mm path) downstream; 0.0015” (38m) thick Al foil to air |
Mama slits table** | 2A | 31.1 | Monash prototype (ver. 1) IC usually here - two 50m Kapton windows; 0.6m air path in between Be windows |
Be window** | 2A | 31.5 | polished; 0.35mm thick; He-flushed (81mm path) upstream; 0.0015” (38m) thick Al foil to air; vacuum downstream |
Upstream side of 2A/2B wall | 2A | 31.748 |
|
Downstream side of 2A/2B wall | 2B | 31.848 |
|
Be window*** | 2B | 32.8 | polished; 0.35mm thick; vacuum upstream & He-flushed (75mm path) downstream; 0.0015” (38m) thick Al foil to air |
Upstream side of downstream 2B wall | 2B | 39.948 |
|
Mask | “coffin” | 40.3 | 3.8mrad x 1.4mrad |
Downstream side of 3A/3B wall | 3B | 135.284 |
|
Be window**** | 3B | 135.8 | polished; 2.0mm thick; vacuum upstream & He-flushed (43mm path) downstream; 0.0015” (38m) thick Al foil to air |
Upstream side of downstream 3B wall | 3B | 145.284 |
|
*only relevant for hutch mode 1
**only relevant for hutch modes 2 and 3
***only relevant for hutch mode 2
****only relevant for hutch mode 3The IMBL sources: Superconducting Multi-pole Wiggle (SCMPW)
Period: 52 mm
Pole pairs (total): 30 (59 full field + single 3/4 and 1/4 at each end)
K (max): 20.4
SCMPW source brilliance: 1 x10^16 ph/sec/mm2/mr/0.1%bw at the peak
Normal operation at 3.0 T field: K=14.6, Ecrit=18.0 KeV
Period length(mm) | 52 |
Number of periods | 31 |
Maximum magnetic field strength at electron beam position | 4.17 T |
Maximum deflection parameter, K | 18.7 |
Length of magnetic structure (m) | 1.5 |
Critical Energy at maximum field (keV) | 25 |
Total Power at maximum field (kW) | 29.5 |
Total power entering beamline at maximum field (kW) | 23 |
With storage ring electron beam at 3.o GeV and 200 mA
Attenuators and filters
There is no fixed primary window. Only differential pumping isolates the beamline vacuum from the machine vacuum in normal operation.
There is a CVD diamond primary filter to remove low energies, before the beam enters the beamline.
In-vacuum Filters
The Paddle number increases going downstream i.e. Paddle 1 is closest to the source. Green highlighting indicates the essential filter set. Changes to these filters to be made only after verification with the IMBL staff.
Note: these are foil thicknesses. The material thickness seen by the beam is a factor of 1.414 more, since the foils are presented at 45 degrees to the beam.
Paddle number | Foil Position | Foil Material | Foil Thickness (mm) |
|---|---|---|---|
1 | 1 | white beam | ---- |
1 | 2 | Graphene sheet | x 18=0.45 mm |
1 | 3 | Graphene sheet | x 1=0.025 mm |
1 | 4 | Graphene sheet | x 10= 0.25 mm |
2 | 1 | white beam | ---- |
2 | 2 | HD graphite | 5.0 |
2 | 3 | Flex. graphite | 5.0 |
2 | 4 | Flex. graphite | 3.0 |
3 | 1 | white beam | ---- |
3 | 2 | HD graphite | 10.0 |
3 | 3 | Flex. graphite | 5.0 |
3 | 4 | Aluminium | 1.0 |
4 | 1 | white beam | ---- |
4 | 2 | Aluminium + Aluminium | 1.0 + 1.0 = 2.0 mm |
4 | 3 | Molybdenum + Aluminium | 1.0 + 1.0 mm |
4 | 4 | Copper | 2.0 |
5 | 1 | White beam | --- |
5 | 2 | Aluminium + Molybdenum | 1.0 + 1.0 |
5 | 3 | Copper | 1.0 |
5 | 4 | Aluminium + Aluminium | 1.0 + 1.0 = 2.0 mm |
Monochromator
Bent Double Laue
Energy range: 25 – 120 keV
Energy resolution: 1 : 10^-3
Crystal material: silicon
Vertical offset: Upwards 20 – 25 mm
Cooling: Water
Further details can be found in the Monochromator Page.
Primary Slits
Scissor slits in the vertical, independent slits horizontal.
Water cooled. Able to handle the full beam power at 4.0 T.
Nominal distance of 13.5 metres from Tangent Point (TP).
Hutches and beam sizes
IMBL has three pairs of optics + experiment hutches:
1A/1B: with an entrance window ~20 metres from TP
2A/2B: with an entrance window ~32 metres from TP
3A/3B with an entrance window ~136 m from TP.
The two tables below are for a maximum field (4.17T) horizontal and vertical beams at 23 metres (Hutch 1B). Red numbers indicate the width is outside the current limits set by the front-end or tunnel mask.
Horizontal
Beam energy (keV) | 10% roll-off width (mm) | FWHM (mm) |
|---|---|---|
20 | 117 | 138 |
40 | 69 | 120 |
60 | 52 | 104 |
80 | 43 | 92 |
100 | 37 | 84 |
120 | 33 | 77 |
Vertical
Beam energy (keV) | 10 % roll-off limit (mm) | FWHM (mm) |
|---|---|---|
20 | 3.6 | 7.1 |
40 | 2.1 | 4.9 |
50 | 1.6 | 3.9 |
80 | 1.3 | 3.3 |
100 | 1.2 | 2.9 |
120 | 1.1 | 2.6 |
The two tables below are for horizontal and vertical beams at 38 metres (Hutch 2B). Red numbers indicate the size is outside the current limits set by the masks.
Horizontal
Beam energy (keV) | 10 % roll-off width (mm) | FWHM (mm) |
|---|---|---|
20 | 194 | 228 |
40 | 114 | 198 |
60 | 85 | 172 |
80 | 71 | 153 |
100 | 61 | 138 |
129 | 55 | 127 |
Vertical
Beam energy (keV) | 10 % roll-off width (mm) | FWHM (mm) |
|---|---|---|
20 | 5.9 | 11.7 |
40 | 3.5 | 8.0 |
60 | 2.6 | 6.4 |
80 | 2.2 | 5.4 |
100 | 1.9 | 4.8 |
120 | 1.7 | 4.3 |
The two tables below are for beam sizes at 130 metres (Hutch 3B). Red numbers indicate the width is outside the current limits set by the mask.
Horizontal
Beam energy (keV) | 10 % roll-off width (mm) | FWHM (mm) |
|---|---|---|
20 | 664 | 781 |
40 | 392 | 677 |
60 | 292 | 588 |
80 | 242 | 522 |
100 | 211 | 473 |
129 | 189 | 435 |
Vertical
Beam energy (keV) | 10 % roll-off width (mm) | FWHM (mm) |
|---|---|---|
20 | 20 | 40 |
40 | 12 | 27 |
60 | 9 | 22 |
80 | 7.5 | 19 |
100 | 6.6 | 16 |
120 | 6 | 15 |
Position and motion control
The beam center is approximately 1.4 m above the floor, and central in each of the hutches.
By convention the direction along the beam is called X, horizontal (perpendicular) is Y, and vertical is Z.
Positioning of samples / apparatus in the beam is enabled using a pair of central rails, and a pair of optical tables.
The tables have motorised Y and Z translation. Designed for loads up to 100 Kg.