Phase-space collimator for transverse acceptance measurement

Kashiwagi, Hirotsugu; Miyawaki, Nobumasa; Okumura, Susumu; Ishibori, Ikuo; Kurashima, Satoshi; Yuri, Yosuke; Ishizaka, Tomohisa; Yuyama, Takahiro; Yoshida, Kenichi; Agematsu, Takashi; Nara, Takayuki; Yokota, Wataru

It is necessary to match a beam emittance to an acceptance to minimize a beam loss in an accelerator. In JAEA Takasaki, an emittance and acceptance measurement device is being developed to evaluate the emittance matching to the acceptance. The method of acceptance measurement is as follows. A beam which occupies a small area in phase-space is injected into an accelerator. A detector after the accelerator determines whether the beam pass through the accelerator. The area in phase-space in which the detected beam occupies at the injection is a part of the acceptance. To measure whole acceptance the measurement is done by varying the position of the small area in phase-space. The device to collimate the area in transverse phase-space in the injected beam was developed. It is consisted of two pair of position slit and angle slit so that arbitrary area in two dimensional or four dimensional phase-space could be injected into the accelerator.