Beam diagnostics in the beamlines Sergey Sadovich CERN BE-BI-PM on behalf of BE-BI-PM

Outline HIE-ISOLDE diagnostic system overview Short and long diagnostic boxes Instruments and devices Faraday Cup Scanning slit Collimator and stripping foils Silicon detector

Diagnostic boxes:

Possibilities: Beam current measurement Profile and position measurement Beam emittance Energy of beam measurement Stripping foils

Types of DB:

Short and Long diagnostic boxes Due to tight space constraints in the longitudinal direction, two designs for the DBs were implemented: Linac: Short DBs (5). HEBT: Long DBs (8). The functionality and operation of the instruments is similar in the SDBs and LDBs. The only difference between them is that the SDBs have a compact Faraday cup. Depending on which devices are included on each DB, there can be up to 4 different types/configurations of DBs. scanning slit stripping foils FC Si. det collimators vacuum port beam short FC long FC

Instruments summary Instrument Inputs Outputs Plane * Positions Connected to Faraday cup V repeller I signal plate 2 IN – OUT FC preamplifier + VME board Scanning slit 1 continuous stroke 135 mm Si detector HV particle energy and time of arrival and continuous adjustment preamplifier + VME digitizer V1724 Collimators 1 4 setpoints and continuous adjustment Collimators 2 Stripping foils 3 setpoints and continuous adjustment

Faraday Cup FC working zone Design for short FC Ibeam IFC Vrep -67 V

Faraday Cup Final design Ibeam IFC Vrep

Scanning slit A blade with a V-shaped slit is scanned upstream the FC. Detector Beam A blade with a V-shaped slit is scanned upstream the FC. Vertical and horizontal profiles are acquired, and the beam position is calculated from them. A 1 mm collimator hole is also included in the blade and can be used for beam alignment. The position of the blade needs to be controlled for the full stroke (135 mm). The actuator is driven by a stepper motor.

Transverse profile: scanning slit + FC Horizontal and vertical profiles. Beam size and position.

Transverse emittance: 2 slits + FC can be implemented with 2 DBs at the HEBT (d = 2.6 m) MonteCarlo simulation of particles transport optimal slit width w = 1 mm

Scanning slit: position measurement

Collimators and stripping foils Preset positions (1 to 4, or OUT) or arbitrary value. Actuator driven by a stepper motor.

Collimators: position measurement

charged particles spectroscopy Silicon detector preamplifier energy chain charged particles spectroscopy Total particle energy Mass composition timing chain time of flight Particle speed Bunch length energy spectrum TOF spectrum Works at an average rate of ~100s particles per second. Beam intensity needs to be severely reduced placing collimating foils in DB2 and DB3. Detector bias (60 or 100 V) supplied through the preamplifier. Preamplifier power: ±24 V, ±12 V provided by shaper amplifier. Leakage current monitoring can be used to determine detector aging and also to block the beam if dose rate is too high. Requires the time signal for the RF master-oscillator and the EBIS pulse for triggering the TDC and gating the acquisition. Integration time controlled by the user.

Implementation: Canberra PIPS detector (TM)PD50-11-300AM 50 mm2 Resolution 11(16) keV FWHM for 241Am, 5.486 MeV alphas Canberra 2003BT The output provides a voltage in direct proportion to the collected charge at the rate of 0.45 V per pC. This translates to a gain of 20 mV per MeV for room temperature silicon detectors. CAEN V1724 with DPP-PHA VME module with 8 Channels 14 bit 100 MS/s Flash ADC Waveform Digitizer and featuring 10 Vpp input dynamics 0-10V /20 mV = 0-500 MeV 500 MeV / 2^14 = 30.5 keV per bit

Summary DBs in tunnel are installed DBs for XT01 line are installed DBs for XT02 line are ready to be installed Stripping foils have to be installed Silicon detectors for SDB5 and LDB6 have to be installed Following measurements can be performed Beam intensity: Faraday cup (+ collimators). Setting up the accelerator and aligning and transporting the beam. Beam transverse profiles (and position): Scanning slit + FC. Horizontal and vertical profiles. Beam longitudinal profile: Silicon detectors. Energy and time spectra. Time of flight measurements Transverse emittance: 2 scanning slits + FC Stripping foils.