# Measurement of the electron transmission rate of the gating foil for the TPC of the ILC experiment

## TL;DR

This paper reports on the development and measurement of a gating foil for a TPC in the ILC, focusing on its electron transmission rate and ion blocking capabilities, crucial for detector performance.

## Contribution

It introduces a novel gating foil with a high optical aperture ratio that functions as an ion gate without gas amplification, and measures its electron transmission properties.

## Key findings

- Electron transmission rate varies with applied voltage.
- The foil effectively blocks positive ions.
- The device operates without gas amplification.

## Abstract

We have developed a gating foil for the time projection chamber envisaged as a central tracker for the international linear collider experiment. It has a structure similar to the Gas Electron Multiplier (GEM) with a higher optical aperture ratio and functions as an ion gate without gas amplification. The transmission rate for electrons was measured in a counting mode for a wide range of the voltages applied across the foil using an $^{55}$Fe source and a laser in the absence of a magnetic field. The blocking power of the foil against positive ions was estimated from the electron transmissions.