Study of nucloen-nucleon interaction through inelastic scattering of protons

本文介绍了一个用于高分辨光谱仪“Grand Raiden”的焦平面计数器系统。它由两个垂直型漂移室（VDC）和两个塑料漂移室组成。采用VDC作为位置计数器，x。利用VDC'S的位置信息计算了粒子的θ、y和φ坐标。该触发器主要用作数据采集系统的触发信号源。它们还用于提取位置和能量损失信息。该系统的探测效率大于98%，位置分辨率小于0.3mm，角分辨率小于2 mr。该计数器系统已安装在“大雷电”的焦平面上。经过多次加速束流性能测试，在入射能量为300 MeV时，测量了质子非弹性散射谱。在~^ C靶的情况下<12>，即使在2 °的小散射角下也能获得低本底谱，从N-N相互作用的角度看，有两个1 ~^+能级，Ex=15。1 MeV（T=I）和Ex=12.7MeV（T=O）的能量是重要的。它们是由N-N相互作用的不同成分激发的，因此，可以提取各种成分的相对强度。非弹性散射的测量仍在进行中，从这些数据中提取的信息提供了一个有用的手段来测试有效相互作用的可靠性，这是由几个小组提出的。

A focal plane counter system for the high resolution spectrometer, "Grand Raiden", has been constructed. It consists of two virtical-type drift chambers (VDC's) and two plastic scintillators. The VDC's are adopted as position counters, and x. theta, y and phi coordinates of particles have been calculated using the position information from the VDC'S. The scintillators are primarily used as a source of trigger signals to the data taking system. They are also used to extract position and energy-loss information. Such information is useful in background reduction and particle identification.The overall detection efficiency of the VDC's is higher than 98% and the position and angular resolutions of counter system are less than 0.3mm and 2mr, respectively. This performance is higher than requirement to make high resolution measurements using the spectrometer.This counter system was set on the focal plane of "Grand Raiden". Following several times of performance test using accelerated beam, the spectra of proton inelastic scattering have been, measured at the incident energy of 30OMeV. In the case of ^<12>C target, low background spectrum was obtained even at the small scattering angle of 2 degrees.From the view point of N-N interaction, two 1^+ levels, Ex=15. lMeV (T=I) and Ex=12.7MeV (T=O), are important. They are excited by different components of N-N interaction and, therefore, it is possible to extract the relative strengths of various kinds of components.Measurements of inelastic scattering are still in progress and information extracted from these data provide a useful means to test the reliability of effective interactions, which are proposed by several groups.