Study of nucloen-nucleon interaction through inelastic scattering of protons

构建了高分辨率光谱仪“大雷电”的焦平面计数系统。它由两个垂直漂移室（VDC）和两个塑料闪烁体组成。采用VDC作为位置计数器，利用VDC的位置信息计算粒子的x、y、phi坐标。闪烁体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。这些信息在背景还原和粒子识别中是有用的。VDC的整体检测效率高于98%，计数器系统的位置和角度分辨率分别小于0.3mm和2mr。这一性能高于使用光谱仪进行高分辨率测量的要求。这个计数器系统被设置在“大雷电”的焦平面上。经过多次加速束流性能测试，测量了质子在入射能量为30OMeV时的非弹性散射光谱。在^<12>C目标下，即使在2度的小散射角下也能获得较低的背景光谱。从N-N相互作用的角度来看，两个1^+能级，Ex=15。lMeV （T=I）和Ex=12.7MeV （T=O）是重要的。它们被N-N相互作用的不同组分激发，因此，可以提取各种组分的相对强度。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种有用的方法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.