BNMR: Experimental Modes
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Introduction
This page describes the different Experimental Modes (also known as PPG Modes) available for the bnmr and bnqr experiments. Not all Experimental Modes are supported for both bnmr and bnqr experiments. New Modes are added as needed.
For all Experimental Modes, a PPG-template is used to produce the PPG loadfile. Several Experimental Modes may share the same PPG-template. A timing diagram is provided for each Refer also to the timing diagram for the mode (several modes may share the same timing diagram). See full list of modes here.
All modes are of Type 1 (c.f. I-musr), type 2 (c.f. TD-Musr), or a combination of both types. All Type 1 modes have a designation starting with "1", e.g. "1a","1f". Similarly all type 2 modes start with a "2", e.g. "2a", "2e". Some modes also have a name, e.g. Mode "10" is called "Scalers", Mode "20" is called "SLR". The more commonly used modes are described under #Experimental Mode Parameters.
Note that the data are saved in different histograms depending on whether the mode is Type 1 or Type 2. The combination modes are given a type designation (1 or 2) according to how their histograms are saved.
Type 1 (I-MUSR)
In Type 1 modes, a variable is incremented between a maximum and a minimum value forming a "scan", which is then repeated. At each increment, one of more PPG Cycles are run, and the data are stored in histogram memory in the frontend. In this mode, the histogram data are output after each increment, and saved as MIDAS-format data by the standard MIDAS logger mlogger. The helicity may be flipped after each complete scan, or, in some modes, after each PPG Cycle. The frontend histogram memory is cleared after the data are output at each scan increment. This MIDAS-format file is then converted to MUD-format by the MIDAS client mdarc.
Type 2 (TD-MUSR)
In Type 2 modes, the scaler data for each PPG Cycle is accumulated in the histogram memory in the frontend. The RF may be turned on for part of the cycle. The histogram memory is only cleared at the begin-of-run, and the histograms are accumulated within the frontend. Periodically, the data is read out bymdarc, and saved directly into MUD format.
Selecting an Experimental (PPG) Mode
The available PPG Modes are displayed and selected using the bnmr or bnqr custom status page. Each mode has its own set of run parameters, which are displayed on the Parameters Page (see review the run parameters). Some run parameters are common between the modes (e.g. helicity). The run parameters for the more common experimental modes are described in #Experimental Mode Parameters below.
Experimental Mode Parameters
- NOTE
- Not all experimental modes are supported for both experiments.