# Presentation: 682172

## Constraints and Compromises in Planning NSLS-II Beamlines 

**Andy Broadbent, Beamlines Manager,**
**EFAC Meeting **
**  ****Monday 5****th**** May, 2008**

## General Constraints

- Safety Constraints.
- Building Constraints:
- LOBs;

**General Constraints**

## General Constraints

- Safety Constraints.
- Building Constraints:
- LOBs;
- Column positions;
**Floor space**.

**General Constraints**

## General Constraints

- Safety Constraints.
- Building Constraints:
- LOBs;
- Column positions;
- Floor space.
- Accelerator Constraints:
- Injection straight;
- RF straights;
- 3 or 5 fold symmetry;
- Devices on high beta straights;
- Diagnostics.
- Grouping of beamlines.

**General Constraints**

## Safety

- Emergency egress from facility.
- Standard width access aisles.
- 50’ maximum “dead-end” _*strongly*_ recommended.
- Ideally have gap between FOE and experiment stations.
- This gives a exit route via a beamline “duck-under”.
- Normally feasible, occasionally not possible.
- Do not locate such beamlines in adjacent positions.

## GOOD!Choice of emergency exit routes

- GOOD!Choice of emergency exit routes

## Choice of emergency exit routes not always possible.  

**Choice of emergency exit routes not always possible.  **
**Care is needed in locating such beamlines.**

## Floor Space

**Floor Space**

**10’ expansion of floor – a critical change**

## Dual Protein Crystallography Beamlines on a Canted Undulator Source.

**Dual Protein Crystallography Beamlines ****on a Canted Undulator Source.**

- Layout worked out in conjunction with ACCEL who have designed a “revised GMCA-CAT” based beamline that will fit without compromise.

## Floor Geometry

## Beamlines passing outside the facility require a low level “bypass”, this gives the opportunity for extra floor space.

**Vibration isolation**

**Previous vibration isolation joint position**

**Extra 10’ of floor length**

**Beamlines passing outside the facility require a low level “bypass”, this gives the opportunity for extra floor space.**

## Options for DW placement with 3 or 5 fold symmetry.

| Three fold symmetry Options |  |
| --- | --- |
| 2,12,22 | RF straight conflict |
| 4,14,24 | RF straight conflict |
| 6,16,26 | OK |
| 8,18,28 | OK |
| 10,20,30 | Injection straight conflict |
| Five fold symmetry Options |  |
| 2,8,14,20,26 | OK |
| 4,10,16,22,28 | RF straight conflict |
| 6,12,18,24,30 | RF and injection straight conflict |

- Damping wigglers may only be located in high beta (even numbered) straights.
- The possible options are tabulated below.

**Options for DW placement with 3 or 5 fold symmetry.**

**Symmetry Considerations**

## Possible damping wiggler locations:

**Symmetry Considerations**

**Possible damping wiggler locations:**

**Option 1: 6,16,26**

**Option 2: 8,18,28**

**Option 3: 2,8,14,20,26**

## Large Gap Dipole Chambers for Far-IR.

**Symmetry Considerations**

**Large Gap Dipole Chambers for Far-IR.**

**We can take advantage of unused floor space on other side of the ratchet wall... here.**

## IR Cabins

- Horizontal extraction is desirable for the far-IR beamline.  This is only possible in a few places at NSLS-II.

- Photos courtesy of the Australian Synchrotron

## Vertical extraction scheme proposed for the mid-IR beamlines at NSLS-II 

- Vertical extraction scheme proposed for the mid-IR beamlines at NSLS-II

## Extended Length Straights

- Very desirable for IXS beamline where a very long undulator would have a significant scientific impact.
- There is a feasibility study for extending straights, at the cost of reducing the length of the adjacent short straights (dipole and focusing magnets move outward).
- Extended length straights would need to have three fold symmetry.
- Care needs to be take with devices +/-10 straights away from IXS, plus with the adjacent six short straights.
- Position would be critical as tunnel walkway would become narrower.

## Devices on High Beta Straights

- High field and/or short period device will cause amplitude dependent tune shift;
- this is undesirable on a new machine
- aim to avoid making commissioning any more difficult
- carefully select devices for high beta straights to give no greater impact than DWs.
- Superconducting wigglers cannot go on high beta straights.
- IVU specifications need to be carefully reviewed prior to locating on a high beta straight.

## Grouping of Beamlines: Scientific Villages

- Many User groups expressed the desire to co-locate beamlines with a similar theme, for example;
- one sample, several techniques,
- laboratory requirements,
- sample environments.
- Efficiency of facility staffing.
- Promote User interaction.
- Promote sharing of a single technique between communities.
- Dynamic scientific environment for facility staff.

## Summary

- There are lots of constraints.
- Strawman layout does not currently exist.
- We cannot satisfy everyone!
- Some compromises are needed.
- Advice or comment sought from EFAC