List of R&D questions for 2021

Support Structure R&D Items 2021

Have both inner and outer EMCal faces at the same transverse plane?

• Note that the blocks in the outer EMCal are at least twice as long as those for the inner part – have to also consider the center of gravity  having the faces not at the same transverse plane may be preferable

• JLab Hall D FCAL insert (inner=PWO, outer=lead glass) designed with faces not at the same transverse plane

• Concern for not having the faces in the same transverse plane: may get some showers in the outer EMCal starting to develop from some depth (not from the face), which may result in significant longitudinal leakage (at least for the part of the shower developing in the outer EMCal).

Integration of the EMCal support structure with HCal or a standalone solution for EMCal?

• In an integrated design with HCAL access to the EMCal readout (should be on the EMCal back, hence between EMCal and HCal), requires opening of the endcap (here HCal+EMCal) for any service and even further separation for maintenance
• A standalone design is mechanically challenging – any examples?

Projectivity

• Projectivity seems not needed for the electron endcap based on experience at other facilities, e.g. JLab, PANDA. And there is a major cost impact as the production of projective PWO is more expensive than non-projective - the design is also more complex, e.g. at PANDA 11 different shapes were needed for the barrel EMCal.
• Furthermore, both the PWO crystals and the lead glass that could potentially be recycled for the EIC electron endcap are non-projective.

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