Installation of a Passive ZDC Module in TAN Motivation: Test radiation hardness of materials that are considered for an liquid radiator upgrade of the ZDC. Materials will be tested for the optical properties and isotopic and chemical composition before and after irradiation. Schedule: Installation during TSP 2, week of September 12th (as best fits overall schedule) Removal during TSP 3, week of November 7th (as best fits overall schedule) Material tests to occur after cool down period TBD by RP Device: Passive aluminum test container (ACT) with dimensions of ZDC hadron module. The ACT will contain W-plates, aluminized-mylar and gold-reflectors, 3 different mineral oils and quartz windows. Procedures: For installation and safety it is proposed to follow procedures and safety measures that have been established for the ZDC installation and removal. Procedures and safety measures for the irradiated material testing will be established with RP. ECR draft has been distributed to ZDC group. Funding and manpower: NSF (at CERN through UIUC team account), ATLAS ZDC group in particular graduate students and technicians Matthias Grosse Perdekamp, UIUC

Motivation: ZDC in High Radiation Environment Radiation exposure leads to aging that manifests itself in rapid decrease in light attenuation length. Present solution: only operate in Pb-Pb and p-Pb + replace quartz as needed. Proposal: replace quartz with liquid radiator that can be replaced easily (possibly during operations). Test lq radiators together with other ZDC materials in TAN to study impact radiation driven chemistry in this environment has on optical properties of lq radiators, reflectors and PMT quartz windows.

ATC Materials Container: Aluminum Shielding: Tungsten Plates Seals: Gold foil Reflectors: Gold foil and aluminized mylar Liquid radiators: 2.5 l of mineral oils (flash points 140-180 Co)

Liquid Radiators

Aluminum Test Container Dimensions in mm mirror external dimensions of ZDC hadronic module. Design has been sent to ATLAS Tool and Die in Chicago to evaluate possibility to manufacture by Wire EDM. The top and the bottom covers will be machined separately. Material: Al-6061 Liquid radiator + Absorber (Tungsten) Shielding Compartment (5 Tungsten Plates)

Tungsten Plates and Liquid Radiator Placement Tungsten Plates (Only 180 mm deep) coated with reflector material sheets Tungsten Plates and Liquid Radiator Placement in the ATC, approximate drawing Liquid Radiator

Material Tests Planned For lq radiators: (1) chemical and isotopic composition through spectroscopy. Agreed with RPC on comparison between RP simulations and experimental results. (2) attenuation length & light yield For reflectors: (1) chemical and isotopic composition through spectroscopy. Agreed with RPC on comparison between RP simulations and experimental results. (2) reflectivity For quartz window: (1) chemical and isotopic composition through spectroscopy. Agreed with RPC on comparison between RP simulations and experimental results. (2) transmission

Schedule, Procedures, Manpower & Funding Installation during TS2 – no specific requirements on schedule during TS2, will provide manpower as and when needed. Removal and storage in a UIUC provided sarcophagus during TS3 – no specific requirements on schedule during TS3, will provide manpower as and when needed. Installation and removal procedures can be adapted from the procedures for ZDC module installation and storage. (The ATC is a passive device and we don’t expect to impact the existing safety envelope for work at the TAN.) ECR draft has been submitted to ZDC group for review. Store irradiated ATC in holding bay designated by RP. Keep sealed during cool down. Carry out material tests after cool down time (TBD by RP) in laboratory assigned by RP. RP will assist with spectroscopy of irradiate materials and safety procedures needed. UIUC will prepare apparatus needed for measurement of optical properties. Funding needed available at UIUC and through UIUC team account at CERN, manpower from ZDC group and UIUC as needed