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The 100 MeV Linac of the Proton Engineering Frontier Project (PEFP) consists of an ion source, a low energy beam transport (LEBT), a 3 MeV radio frequency quadrupole (RFQ), and an 100 MeV drift tube linac (DTL). The DTL is separated into two parts. The first part includes 4 tanks which accelerate 20 mA proton beams up to 20 MeV. The medium energy beam transport (MEBT) follows the 20 MeV accelerator in order to match the proton beams into the next linac as well as to extract and supply 20 MeV proton beams to the user facilities. The second part of the DTL consists of 7 tanks to accelerate proton beams to 100 MeV. This work focuses on an error analysis of the designed 100 MeV linac in order to study the steering magnets which control the beam fluctuations and reduce the potential beam loss.

The RF amplitude and the phase stability requirements of the LLRF system for the PEFP (Proton Engineering Frontier Project) proton linac are within 1% and 1 degree, respectively. As a prototype of the LLRF, a simple digital PI control system based on commercial FPGA board is designed and tested. The main features are a sampling rate of 40 MHz which is four times higher than the down- converted cavity signal frequency, digital in-phase and quadrature detection, pulsed mode operation with the external trigger, and a simple proportional-integral feedback algorithm implemented in a FPGA. The developed system was tested with 3 MeV RFQ and 20 MeV DTL, and satisfied the stability requirements.

The beam test of the Proton Engineering Frontier Project (PEFP) 20 MeV proton linear accelerator started again, after the upgrade of the RF control system. One of the important goals during this test period is to increase the beam current to the design level. Various current transformers were installed along the linac to measure the beam current itself and possible beam loss along the accelerator. Also two sets of beam position and phase monitors (BPPM) were installed at the end of the 20 MeV accelerator to measure not only the beam position and phase but also the beam energy. In this paper, the overall test results including beam current and energy measurement are presented.

The temperature-controlled water cooling system has been designed to obtain the resonance frequency stabilization of the normal conducting drift tube linac (DTL) for the PEFP 100 MeV proton linear accelerator. The sizing of individual closed-loop low conductivity cooling water pumping skids for each DTL system is conducted with a simulation of thermo-hydraulic network model. The temperature control schemes incorporating the process dynamic model of heat exchangers is examined to regulate the input water temperatures into the DTL during transient and steady state operation.