BZ-2025-08 QAv3.pdf

RFP BZ-2025-08 Q&A v3 1

April 25, 2025 RFQ BZ-2025-08: SAXS Flight Tube

Questions and Answers v3

Q1: Can you please provide a 3D model of the hutch?

A1: Yes, see the new attachment to the SAM posting. The flight tube volume claim begins

350mm downstream of the sample location. Downstream of this point the potential vendors are restricted only by the hutch dimensions. The model includes both proposed beampaths as outlined in the ESD.

Q2: Can you extend the submission date?

A2: Yes. The new submission deadline is April 30, 2025. Deadline for technical questions has also been extended, until April 23, 2025.

Q3: Will it be possible to enter the hutch using wheels?

A3: Yes, the floor is entirely smooth through the door, so wheeled transport is possible.

Q4: Could you please confirm if the in-vacuum cables and the in-vacuum hoses needed for the detector will be supplied by LBNL? Same question for the feedthrough (cooling feedthrough and electrical feedthrough).

A4: We would prefer if all in-vacuum cables, hoses, and feedthroughs were supplied by the seller. However, if your team feels that there is a sound technical reason why it isn’t possible to commit to that at this stage (e.g. due to uncertainty over the final detector choice) they should state that explicitly in the proposal and we would take that into consideration.

Q5: In the table page 9 of the engineering specification, you request +/-25mm for the Y minimum adjustment range of FT for alignment to primary beam path. This is a quite high range of alignment. Could you accept a smaller stroke (+/-10mm) instead?

A5: The large motion range is required solely to accommodate initial alignment and then occasional translation between the two alternate beampaths with sufficient fine adjustment at each location to facilitate parallelizing the Z travel exactly to the beam axis to within the specified tolerance. If the offeror were to suggest an alternative means of realignment between the two paths that doesn’t require a large, continuous, travel range then we would consider that alternative.

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Q6: In the table page 9 of the engineering specification, you mention a “Minimum sub-region of FT Y range over which fine adjustment is possible with sufficient precision to meet specifications in section 9.5” of +/-12mm. Could you please explain the reason for this requirement? Is it an over-stroke for the detector?

A6: This relates to the previous requirement. We require a large adjustment in Y sufficient to transition between the two beam paths with a fine adjustment (that may or may not be independent of this) to parallelize the FT to the beam path within the required alignment tolerance, at each of these two possible locations. This fine adjustment only needs to be possible in the immediate vicinity of each of these two locations. We don’t mandate fine adjustment for intermediate alignments (indeed there is no requirement to be able to achieve stable intermediate alignments).

Q7: Detector cover: Can we consider that the retractable cover will be placed manually when the detector is located in front of a side door implemented on the vacuum chamber (chamber at atmospheric pressure) or do you require an in-vacuum motorized system?

A7: It must be possible to cover the detector face remotely while the detector is in vacuum.

Attached is a movie of one of our existing detector covers (“LBNL_Cover.mov”).

This movie is intended only to illustrate the function of such a cover; that particular design is actuated by compressed air and so is unsuitable for use in vacuum.

Q8: How close from the upstream flange of the FT vacuum chamber shall we position the detector?

A8: As close as possible but there is no minimum requirement. But the closer the better since it permits a larger solid angle of data to be collected.

Q9: What are the requested sizes of the beamstops (XYZ)? Which material do you recommend for both beamstops?

A9: The existing beamstop is 8x2x4mm (HxWxD) of tungsten. However the exact size is not particularly critical as we envision having to replace this periodically.

Q10: You request an X stroke of 200mm for the beamstops, is it to switch from one beamstop to the other one?

A10: This is to permit the beamstop to be fully withdrawn beyond the edge of the detector face. We could settle for less if this turned out to be a major technical challenge.

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Q11: You request an Y stroke of 20mm for the beamstops, is it the necessary stroke to put the beamstop out of the beam?

A11: This is an estimated stroke to move the beamstop out of the direct beam. It is also large enough to allow for a second diagnostic to be added later and for the stroke to be used to move between them.

Q12: Do we have to foresee a cooling system for the beamstop?

A12: No.

Q13: Do you request any viewport on the vacuum chamber?

A13: Yes, at a minimum one that will allow us to see the detector face and confirm that the cover is open, or the face isn’t damaged.

Q14: Do you need to have a lighting system to see inside the vacuum chamber?

A14: No.

Q15: As the 9 mrad pitch rotation will be at 2m from the incoming flange of the Flight

Tube and the yaw rotation of 9 mrad will be at 1.5m from this flange, can we consider a common pitch/yaw center of rotation located at 1.75 m from the start of the FT (and having therefore only 1 common pivot along Z axis)?

A15: Yes, providing that the Z axis can be parallelized to the beam axis in both configurations.

Q16: Regarding the beam height, on paragraph 9.2 it is written that “the primary axis is parallel to the floor and at a height of 1240 mm.” In table 9.2a, it is written that when the KB mirrors are retracted the beam height will be at 1183 mm (and therefore not 1240); furthermore in this table we can see that when the KB mirrors are retracted the difference in beam height is 39 mm between the exit and the start of the Flight Tube (it should be horizontal). Is there any inversion of lines in this Table?

A16: When the KBs are retracted the upward bounce of the VFM is eliminated from the beam path, therefore the undeflected beam continues descending at 4.5mrad along the length of the hutch when this “secondary” geometry is in use. The beam is only parallel to the floor for the “primary” beam path, the one with VFM inserted.

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Q17: For a tube length of 4.3 m, we can consider that the deviation of 9 mrad for the pitch & yaw corresponds to a linear lateral and vertical deviations of ~39 mm. Table of page 9 indicates that the total stroke for “additional X adjustment of FT required to accommodate alternate beam path” is 40 mm (=55-15), which corresponds indeed to the 9 mrad. Nevertheless on page 10, the total stroke for “additional Y adjustment of FT required to accommodate alternate beam path” is only 35 mm (=55-20). Is there a mistake for the Y stroke?

A17: The HFM and VFM mirrors are 500mm apart and so when they are retracted the pivot point for the H and V displacement of the flight tube are at different locations.

The upwardly deflecting VFM is 2m upstream of the start of the FT and so removing it causes a 9mrad rotation downwards of the beam path. That becomes 18mm downward motion at the start of the FT and 54mm at the end. (assuming 4m length).

I rounded these up to -20mm and -55mm in table 9.2a.

The HFM is 1.5m upstream of the FT and inboard deflecting (towards the hutch door) and so removing it causes a 9mrad outboard (towards the hutch wall) rotation of the beampath which results in horizontal movements of +13.5mm at the start of the FT and +49.5mm at the end (assuming 4m length).

I rounded these to +15 and +55 mm in the spec. However, in reviewing these numbers it appears that the +55 is a copy/paste error and it should be 50mm.

This adjustment to reach the new beam path is additional to the adjustment which is required for general installation alignment (that constitute the first four lines of table 9.2a).

The reason for listing the general adjustment range required for installation alignment separately from the adjustment range needed to accommodate the two beam paths is in case the subcontractor wishes to accommodate these two different move requirements using two different methods since there is no requirement to be able to achieve alignments that are intermediate between the two beam paths.

However, we have no preference for how either motion is implemented.

Also see the response to question 15 above.

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Q18: In the table of page 9 it is written that “the Z minimum adjustment shall be +- 15 mm”. Do you need absolutely this degree of freedom along the beam propagation axis?

A18: If the offeror is confident that the tube can be installed and aligned satisfactorily without an adjustment of the Z axes then we would consider that solution.

Q19: In the table of paragraph 9.5 (page 12), you ask at 2 occasions that the detector X movement resolution shall be better than 100 um. Should we understand that the second requirement concerns Y axis?

A19: Correct. It should be 100µm in X and 100µm in Y.

Q20: In the table of paragraph 9.5 (page 12), you ask for a detector stability better than 5µm; but over which period of time?

A20: High static stability is required only during active data collection. 5 minutes would be sufficient to demonstrate this capability.

Q21: In table of paragraph 9.6 (page 13), you ask that “one beamstop shall include a beam visualization system with a resolution of better than 10um.” Putting a sort of camera in a beamstop will enlarge too much the size of the beamstop, would you accept an independent system of measure (i.e. placed outside of the beamstop) as a beamviewer?

A21: Yes.

Q22: In section 9.2, it states the following: "Realignment between alternative beampaths can be achieved via manual adjustment. Although LBNL may consider subcontractor proposed motorized solutions as an additional option." Given the large price difference between the two options, could the two options be presented separately in the price proposal for evaluation by LBNL?

A22: Yes, it could be presented as a separate option.

Q23: With regard to structural integrity and, more specifically, the fatigue check, could you please provide an approximate figure for the number of vacuum cycles required?

A23: Very rarely, probably two or three times a year, plus maybe 10 times during initial commissioning.

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Q24: Is there a preferred XY beam stop translator vendor? Or is a custom solution required?

A24: LBNL has no preference for a commercial or custom solution. Any solution that is capable of positioning a lump of suitable material to within the required tolerance is acceptable.

Q25: We have not been able to locate off-the-shelf solutions that meet the requirements for the following instrumentation items. Are there recommended or preferred vendors for these?

A. One beamstop shall have an embedded photodiode capable of measuring 10keV beam intensities to better than 0.1% accuracy B. One beamstop shall include a beam visualization system with a resolution of better than 10μm A25:

A. We typically use photodiodes such as the OSI S-100VL. But photodiodes come in many different formats and packages and so there may be a different one that is more optimally matched to whatever solution the is proposed for meeting this requirement.

B. We don’t have a specific solution in mind for this. Such systems typically involve a YAG (or other fluorescent material) that intercepts the beam. The subsequent fluorescent beam image is then viewed by a high magnification camera. Solutions we have used in the past run the gamut from ones that are completely built in-house to systems that are completely commercially integrated.

Q26: What sort of retractable Detector cover is required - Shield Material/thickness requested? There appears to only be 3cm of room between detector face and beam stop for the retractable cover.

A26: No preference. The cover just needs to provide mechanical protection from accidental contact with the detector surface while the detector is in motion or undergoing maintenance. Our existing covers (as seen in the previously supplied movie) are roll-ups and made of ~5mm thick aluminum slats. The cover assembly attaches to the detector bezel and protrudes 25mm (including screw heads) but we have also used sheet steel and other materials or mechanical formats in the past depending on the particular circumstances of the installation.

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