Status of CHICO-X upgrade

To be fully compatible to GRETA, CHICO needs an upgrade to CHICO-X by redesigning the detector chamber and pixelated position-sensing board. The design has been finalized after the design of GRETA holding frame was completed in late 2020. The chamber has an outer diameter of 12.6 inches and a flight path of 13 cm from the target to the cathode board at 49^o. The angular coverage for theta is from 25^o to 77^o for the forward hemisphere and from 103^o to 155^o for the backward hemisphere. The phi coverage is 280^o out of 360^o. The major changes include the sliding O-ring seal for the pressure window and the integrated design for detector chamber. Some detailed design will be presented together with the schedule to complete this project.