14) Response to Questions 1 - RFP MG 07222024.pdf

LBNL Response to Questions 01 Re: LBNL RFQ MG-07222024 – 08/09/2024

1) With reference to AL-1613-0852 Rev.A:

a) Does the sentence “The only parts of the white beam slits capable of intercepting the beam are the blades” mean that the beam should hit the blade before any other component, or that just the blade frontal projection defines the beam absorption area so that, for examples, the fixation holes of the blade should be completely outside the beam footprint being otherwise a point of transparency even if paired with the blade there will be a thick Copper absorber?

LBNL Response: For direct radiation (direction of beam propagation) only the blade’s frontal projection is considered for beam interception.

b) Is it possible placing the water-cooled absorber upstream the blade?

LBNL Response: Not necessary

c) (7.1.1, 7.1.2, 7.2.1, 7.2.2) Where should we guarantee the required overlap? Over the whole beam footprint or just until the beam fan axis at x=0? We are assuming that, looking the slit from the source, the left blade edge would go from +12.5 mm (half max aperture) to (-6.87-2,5) i.e. inboard footprint plus half overlap, and the right blade would go from -12.5 mm (half max aperture) to (5.41+2,5) i.e. outboard footprint plus half overlap. This would justify the request to consider each blade intercepting the whole beam fan footprint

LBNL Response: We want each blade to be able to go from -12.5 mm to +15 mm, and the overlaps of 2.5 mm possible over the whole opening. H blades and V blades should have anti-collision stops.

d) (7.2.1, 7.2.2) The maximum aperture does not let the whole X beam fan MAESTRO passing through (25 mm respect to ± 18.13 mm), and is quite tight for the X beam fan COSMIC (25 mm respect to ± 12.16 mm with less than 0.5 mm of clearance): is it a mistake or the operation does not need to the whole beam passing through?

LBNL Response: ± 18.13 mm is the synchrotron radiation fan size, not the beam size. The beam is smaller; so the 25 mm aperture includes a sufficient margin of safety. However, the blades should be large enough to intercept the SR fan.

e) (7.3.1, 7.3.2) The field of view and the minimum screen size are smaller than the beam fan footprint and in addition the horizontal dimension does not consider the tilt by 45° of the screen so that the horizontal acceptance is even smaller. Do you confirm the minimum screen size as indicated in the specification?

LBNL Response: The screen size is 15 mm, twice as big as the max 6sigma beam for MAESTRO; we won’t be using the screens to block the SR fan

f) 8.2. Do you confirm that you ask for the supply of pump, angle valve, burst disc and gauges?

LBNL Response: Yes, it is confirmed that the pump, angle valve, burst disc, and gauges are part of this RFP

g) And if yes, up to which extent? Pump with controllers and cables (how long in case)?

LBNL Response: Controllers and cables are not part of this RFP

h) Pressure gauges with controllers and cables (how long in case)?

LBNL Response: Controllers and cables are not part of this RFP

i) Given the request to have granite based supports (or to anchor the slit unit to an existing granite base in the case of the WB slit), the acceptable vibrational amplitude of 20 micron with an integrated vibrational displacement at the floor level of 30 nm, do you really need an extensive modal analysis and vibrational characterization during the FAT of the devices in object?

LBNL Response: Yes, modal analysis and vibrational characterization is needed.

2) With reference to AL-1595-2995 rev.B :

a) As far as we understand from named drawing the flange-to-flange longitudinal encumbrance of the white beam slit unit should be 214 mm. The maximum inboard encumbrance should be 90 mm over the whole height while in the outboard side, there is a volume (protrusion zone) in which we can protrude with the actuation mechanisms. Is this correct and completely not negotiable?

LBNL Response: Correct, the outboard protrusion zone is as stated. A feasible model would help us consider opportunities for space negotiations.

We believe that you are referring to the 100mm dimension.

b) About radiation shielding, which are the points to be considered as radiation sources?

c) Any in vacuum point? All the foreseen impact points of the beam? Just the first impact points?

LBNL Response: All components of the vacuum chamber must meet the requirements for indirect (scattered) synchrotron radiation. For anything 'transparent' to radiation (e.g., ceramic feedthroughs) or not credited for shielding (e.g., pumps, gauges), a two-bounce rule of thumb from the direct beam to the exterior generally works. This is just a rule of thumb for design; proposed design will be analyzed by the Radiation Physicist on a case-by-case basis.

d) Is fig. 8.1 just showing the two possible shielding approaches or the Tee piece made sufficiently thick does not guarantee the shielding and a further cover should be combined with it?

Figure 8.1 shows a shielding (both the cover and the thick-Tee) that was approved for another COSMIC white beam component. Only the thick Tee or only the cover is not sufficient.