Since the undulator wall is being bombarded by photon produced in the ILC helical undulator, masks were installed inside the undulator to protect the superconducting undulator as well as the vacuum. The photon energy spectrum was used to calculate the incident power. HUSR software was used to simulate the photon energy spectrum per meter inside the undulator. The influence of adding masks inside the undulator on the photon polarisation and energy spectrum was also studied.